SEC Info  
    Home      Search      My Interests      Help      Sign In      Please Sign In

PENTAIR plc – ‘10-Q’ for 3/31/18 – ‘EX-101.DEF’

On:  Friday, 4/20/18, at 4:58pm ET   ·   For:  3/31/18   ·   Accession #:  77360-18-16   ·   File #:  1-11625

Previous ‘10-Q’:  ‘10-Q’ on 10/24/17 for 9/30/17   ·   Next:  ‘10-Q’ on 7/25/18 for 6/30/18   ·   Latest:  ‘10-Q’ on 4/23/24 for 3/31/24   ·   4 References:   

Find Words in Filings emoji
 
  in    Show  and   Hints

  As Of               Filer                 Filing    For·On·As Docs:Size

 4/20/18  PENTAIR plc                       10-Q        3/31/18   92:10M

Quarterly Report   —   Form 10-Q   —   Sect. 13 / 15(d) – SEA’34
Filing Table of Contents

Document/Exhibit                   Description                      Pages   Size 

 1: 10-Q        Quarterly Report                                    HTML    643K 
 2: EX-10.2     Material Contract                                   HTML     83K 
 3: EX-10.3     Material Contract                                   HTML     82K 
 4: EX-10.4     Material Contract                                   HTML     86K 
 5: EX-10.5     Material Contract                                   HTML     83K 
 6: EX-10.6     Material Contract                                   HTML     83K 
 7: EX-31.1     Certification -- §302 - SOA'02                      HTML     34K 
 8: EX-31.2     Certification -- §302 - SOA'02                      HTML     34K 
 9: EX-32.1     Certification -- §906 - SOA'02                      HTML     29K 
10: EX-32.2     Certification -- §906 - SOA'02                      HTML     29K 
17: R1          Document and Entity Information                     HTML     47K 
18: R2          Condensed Consolidated Statements of Operations     HTML    111K 
                and Comprehensive Income (Loss)                                  
19: R3          Condensed Consolidated Balance Sheets               HTML    109K 
20: R4          Condensed Consolidated Balance Sheets               HTML     36K 
                (Parenthetical)                                                  
21: R5          Condensed Consolidated Statements of Cash Flows     HTML    127K 
22: R6          Condensed Consolidated Statements of Changes in     HTML     80K 
                Equity                                                           
23: R7          Basis of Presentation and Responsibility for        HTML     95K 
                Interim Financial Statements                                     
24: R8          Revenue                                             HTML    111K 
25: R9          Discontinued Operations                             HTML     45K 
26: R10         Share Plans                                         HTML     48K 
27: R11         Restructuring                                       HTML     51K 
28: R12         Earnings Per Share                                  HTML     50K 
29: R13         Supplemental Balance Sheet Information              HTML     77K 
30: R14         Goodwill and Other Identifiable Intangible Assets   HTML     78K 
31: R15         Debt                                                HTML     83K 
32: R16         Derivatives and Financial Instruments               HTML     87K 
33: R17         Income Taxes                                        HTML     36K 
34: R18         Benefit Plans                                       HTML     47K 
35: R19         Shareholders' Equity                                HTML     32K 
36: R20         Segment Information                                 HTML     56K 
37: R21         Commitments and Contingencies                       HTML     38K 
38: R22         Financial Statements of Parent Company Guarantor    HTML    455K 
39: R23         Basis of Presentation and Responsibility for        HTML     83K 
                Interim Financial Statements (Tables)                            
40: R24         Revenue (Tables)                                    HTML     91K 
41: R25         Discontinued Operations (Tables)                    HTML     48K 
42: R26         Share Plans (Tables)                                HTML     37K 
43: R27         Restructuring (Tables)                              HTML     54K 
44: R28         Earnings Per Share (Tables)                         HTML     49K 
45: R29         Supplemental Balance Sheet Information (Tables)     HTML     77K 
46: R30         Goodwill and Other Identifiable Intangible Assets   HTML     79K 
                (Tables)                                                         
47: R31         Debt (Tables)                                       HTML     72K 
48: R32         Derivatives and Financial Instruments (Tables)      HTML     78K 
49: R33         Benefit Plans (Tables)                              HTML     44K 
50: R34         Segment Information (Tables)                        HTML     57K 
51: R35         Commitments and Contingencies (Tables)              HTML     34K 
52: R36         Financial Statements of Parent Company Guarantor    HTML    456K 
                (Tables)                                                         
53: R37         Basis of Presentation and Responsibility for        HTML     44K 
                Interim Financial Statements - Schedule of Effect                
                of Adoption of ASU 2017-07 (Details)                             
54: R38         Basis of Presentation and Responsibility for        HTML     48K 
                Interim Financial Statements - Additional                        
                Information (Details)                                            
55: R39         Basis of Presentation and Responsibility for        HTML     45K 
                Interim Financial Statements - Schedule of Impact                
                of ASC 606 on the Consolidated Statements of                     
                Operations and Comprehensive Income (Loss)                       
                (Details)                                                        
56: R40         Basis of Presentation and Responsibility for        HTML     65K 
                Interim Financial Statements - Schedule of Impact                
                of ASC 606 on the Condensed Consolidated Balance                 
                Sheets (Details)                                                 
57: R41         Revenue - Schedule of Contract Assets and           HTML     50K 
                Liabilities (Details)                                            
58: R42         Revenue - Additional Information (Details)          HTML     39K 
59: R43         Revenue - Performance Obligations (Details)         HTML     39K 
60: R44         Revenue - Geographic Net Sales Information by       HTML     79K 
                Segment (Details)                                                
61: R45         Discontinued Operations Additional Information      HTML     41K 
                (Details)                                                        
62: R46         Discontinued Operations Income Statement (Details)  HTML     54K 
63: R47         Share Plans - Additional Information (Detail)       HTML     36K 
64: R48         Restructuring - Additional Information (Detail)     HTML     40K 
65: R49         Restructuring - Restructuring Related Costs         HTML     35K 
                Included in Selling, General & Administrative                    
                expenses on Consolidated Statements of Income                    
                (Detail)                                                         
66: R50         Restructuring - Restructuring Accrual Activity      HTML     34K 
                recorded on Condensed Consolidated Balance Sheets                
                (Detail)                                                         
67: R51         Earnings Per Share - Basic and Diluted Earnings     HTML     73K 
                Per Share (Detail)                                               
68: R52         Supplemental Balance Sheet Information (Detail)     HTML    128K 
69: R53         Goodwill and Other Identifiable Intangible Assets   HTML     37K 
                - Changes in Carrying Amount of Goodwill by                      
                Segment (Detail)                                                 
70: R54         Goodwill and Other Identifiable Intangible Assets   HTML     49K 
                - Detail of Identifiable Intangible Assets                       
                (Detail)                                                         
71: R55         Goodwill and Other Identifiable Intangible Assets   HTML     32K 
                - Additional Information (Detail)                                
72: R56         Goodwill and Other Identifiable Intangible Assets   HTML     40K 
                - Estimated Future Amortization Expense for                      
                Identifiable Intangible Assets (Detail)                          
73: R57         Debt - Debt and Average Interest Rates on Debt      HTML     73K 
                Outstanding (Detail)                                             
74: R58         Debt - Additional Information (Detail)              HTML     94K 
75: R59         Debt - Debt Outstanding Matures on Calendar Year    HTML     49K 
                Basis (Detail)                                                   
76: R60         Derivatives and Financial Instruments - Additional  HTML     44K 
                Information (Detail)                                             
77: R61         Derivatives and Financial Instruments - Recorded    HTML     39K 
                Amounts and Estimated Fair Values of Long-term                   
                Debt and Derivative Financial Instruments (Detail)               
78: R62         Derivatives and Financial Instruments - Assets and  HTML     51K 
                Liabilities Measured at Fair Value (Detail)                      
79: R63         Income Taxes - Additional Information (Detail)      HTML     43K 
80: R64         Benefit Plans - Components of Net Periodic Benefit  HTML     41K 
                Cost (Detail)                                                    
81: R65         Shareholders' Equity - Additional Information       HTML     49K 
                (Detail)                                                         
82: R66         Segment Information - Financial Information by      HTML     40K 
                Reportable Segment (Detail)                                      
83: R67         Segment Information Reconciliation of Operating     HTML     52K 
                Profit (Loss) from Segments to Consolidated                      
                (Details)                                                        
84: R68         Commitments and Contingencies - Additional          HTML     28K 
                Information (Detail)                                             
85: R69         Commitments and Contingencies - Changes in          HTML     37K 
                Carrying Amount of Service and Product Warranties                
                (Detail)                                                         
86: R70         Financial Statements of Parent Company Guarantor -  HTML    127K 
                Condensed Consolidating Statement of Operations                  
                and Comprehensive Income (Loss) (Detail)                         
87: R71         Financial Statements of Parent Company Guarantor -  HTML    179K 
                Condensed Consolidating Balance Sheet (Detail)                   
88: R72         Financial Statements of Parent Company Guarantor -  HTML    136K 
                Condensed Consolidating Statement of Cash Flows                  
                (Detail)                                                         
89: R73         Financial Statements of Parent Company Guarantor -  HTML     30K 
                Additional Information (Detail)                                  
91: XML         IDEA XML File -- Filing Summary                      XML    162K 
90: EXCEL       IDEA Workbook of Financial Reports                  XLSX     94K 
11: EX-101.INS  XBRL Instance -- pnr-20180331                        XML   3.43M 
13: EX-101.CAL  XBRL Calculations -- pnr-20180331_cal                XML    284K 
14: EX-101.DEF  XBRL Definitions -- pnr-20180331_def                 XML    747K 
15: EX-101.LAB  XBRL Labels -- pnr-20180331_lab                      XML   1.65M 
16: EX-101.PRE  XBRL Presentations -- pnr-20180331_pre               XML   1.13M 
12: EX-101.SCH  XBRL Schema -- pnr-20180331                          XSD    181K 
92: ZIP         XBRL Zipped Folder -- 0000077360-18-000016-xbrl      Zip    272K 


‘EX-101.DEF’   —   XBRL Definitions — pnr-20180331_def


This Exhibit is an XBRL XML File.


                                                                                                                                                                                
<?xml version="1.0" encoding="windows-1252"?>
<!-- XBRL Document Created with Wdesk from Workiva -->
<!-- -->
<link:linkbase xsi:schemaLocation="http://www.xbrl.org/2003/linkbase http://www.xbrl.org/2003/xbrl-linkbase-2003-12-31.xsd" xmlns:link="http://www.xbrl.org/2003/linkbase" xmlns:xbrldt="http://xbrl.org/2005/xbrldt" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
<link:roleRef roleURI="http://www.pentair.com/role/BasisOfPresentationAndResponsibilityForInterimFinancialStatements" xlink:href="pnr-20180331.xsd#BasisOfPresentationAndResponsibilityForInterimFinancialStatements" xlink:type="simple"/>
<link:roleRef roleURI="http://www.pentair.com/role/BasisOfPresentationAndResponsibilityForInterimFinancialStatementsAdditionalInformationDetails" xlink:href="pnr-20180331.xsd#BasisOfPresentationAndResponsibilityForInterimFinancialStatementsAdditionalInformationDetails" xlink:type="simple"/>
<link:roleRef roleURI="http://www.pentair.com/role/BasisOfPresentationAndResponsibilityForInterimFinancialStatementsScheduleOfEffectOfAdoptionOfAsu201707Details" xlink:href="pnr-20180331.xsd#BasisOfPresentationAndResponsibilityForInterimFinancialStatementsScheduleOfEffectOfAdoptionOfAsu201707Details" xlink:type="simple"/>
<link:roleRef roleURI="http://www.pentair.com/role/BasisOfPresentationAndResponsibilityForInterimFinancialStatementsScheduleOfImpactOfAsc606OnCondensedConsolidatedBalanceSheetsDetails" xlink:href="pnr-20180331.xsd#BasisOfPresentationAndResponsibilityForInterimFinancialStatementsScheduleOfImpactOfAsc606OnCondensedConsolidatedBalanceSheetsDetails" xlink:type="simple"/>
<link:roleRef roleURI="http://www.pentair.com/role/BasisOfPresentationAndResponsibilityForInterimFinancialStatementsScheduleOfImpactOfAsc606OnConsolidatedStatementsOfOperationsAndComprehensiveIncomeLossDetails" xlink:href="pnr-20180331.xsd#BasisOfPresentationAndResponsibilityForInterimFinancialStatementsScheduleOfImpactOfAsc606OnConsolidatedStatementsOfOperationsAndComprehensiveIncomeLossDetails" xlink:type="simple"/>
<link:roleRef roleURI="http://www.pentair.com/role/BasisOfPresentationAndResponsibilityForInterimFinancialStatementsTables" xlink:href="pnr-20180331.xsd#BasisOfPresentationAndResponsibilityForInterimFinancialStatementsTables" xlink:type="simple"/>
<link:roleRef roleURI="http://www.pentair.com/role/BenefitPlans" xlink:href="pnr-20180331.xsd#BenefitPlans" xlink:type="simple"/>
<link:roleRef roleURI="http://www.pentair.com/role/BenefitPlansComponentsOfNetPeriodicBenefitCostDetail" xlink:href="pnr-20180331.xsd#BenefitPlansComponentsOfNetPeriodicBenefitCostDetail" xlink:type="simple"/>
<link:roleRef roleURI="http://www.pentair.com/role/BenefitPlansTables" xlink:href="pnr-20180331.xsd#BenefitPlansTables" xlink:type="simple"/>
<link:roleRef roleURI="http://www.pentair.com/role/CommitmentsAndContingencies" xlink:href="pnr-20180331.xsd#CommitmentsAndContingencies" xlink:type="simple"/>
<link:roleRef roleURI="http://www.pentair.com/role/CommitmentsAndContingenciesAdditionalInformationDetail" xlink:href="pnr-20180331.xsd#CommitmentsAndContingenciesAdditionalInformationDetail" xlink:type="simple"/>
<link:roleRef roleURI="http://www.pentair.com/role/CommitmentsAndContingenciesChangesInCarryingAmountOfServiceAndProductWarrantiesDetail" xlink:href="pnr-20180331.xsd#CommitmentsAndContingenciesChangesInCarryingAmountOfServiceAndProductWarrantiesDetail" xlink:type="simple"/>
<link:roleRef roleURI="http://www.pentair.com/role/CommitmentsAndContingenciesTables" xlink:href="pnr-20180331.xsd#CommitmentsAndContingenciesTables" xlink:type="simple"/>
<link:roleRef roleURI="http://www.pentair.com/role/CondensedConsolidatedBalanceSheets" xlink:href="pnr-20180331.xsd#CondensedConsolidatedBalanceSheets" xlink:type="simple"/>
<link:roleRef roleURI="http://www.pentair.com/role/CondensedConsolidatedBalanceSheetsParenthetical" xlink:href="pnr-20180331.xsd#CondensedConsolidatedBalanceSheetsParenthetical" xlink:type="simple"/>
<link:roleRef roleURI="http://www.pentair.com/role/CondensedConsolidatedStatementsOfCashFlows" xlink:href="pnr-20180331.xsd#CondensedConsolidatedStatementsOfCashFlows" xlink:type="simple"/>
<link:roleRef roleURI="http://www.pentair.com/role/CondensedConsolidatedStatementsOfChangesInEquity" xlink:href="pnr-20180331.xsd#CondensedConsolidatedStatementsOfChangesInEquity" xlink:type="simple"/>
<link:roleRef roleURI="http://www.pentair.com/role/CondensedConsolidatedStatementsOfOperationsAndComprehensiveIncomeLoss" xlink:href="pnr-20180331.xsd#CondensedConsolidatedStatementsOfOperationsAndComprehensiveIncomeLoss" xlink:type="simple"/>
<link:roleRef roleURI="http://www.pentair.com/role/CondensedConsolidatedStatementsOfOperationsAndComprehensiveIncomeParenthetical" xlink:href="pnr-20180331.xsd#CondensedConsolidatedStatementsOfOperationsAndComprehensiveIncomeParenthetical" xlink:type="simple"/>
<link:roleRef roleURI="http://www.pentair.com/role/Debt" xlink:href="pnr-20180331.xsd#Debt" xlink:type="simple"/>
<link:roleRef roleURI="http://www.pentair.com/role/DebtAdditionalInformationDetail" xlink:href="pnr-20180331.xsd#DebtAdditionalInformationDetail" xlink:type="simple"/>
<link:roleRef roleURI="http://www.pentair.com/role/DebtDebtAndAverageInterestRatesOnDebtOutstandingDetail" xlink:href="pnr-20180331.xsd#DebtDebtAndAverageInterestRatesOnDebtOutstandingDetail" xlink:type="simple"/>
<link:roleRef roleURI="http://www.pentair.com/role/DebtDebtOutstandingMaturesOnCalendarYearBasisDetail" xlink:href="pnr-20180331.xsd#DebtDebtOutstandingMaturesOnCalendarYearBasisDetail" xlink:type="simple"/>
<link:roleRef roleURI="http://www.pentair.com/role/DebtTables" xlink:href="pnr-20180331.xsd#DebtTables" xlink:type="simple"/>
<link:roleRef roleURI="http://www.pentair.com/role/DerivativesAndFinancialInstruments" xlink:href="pnr-20180331.xsd#DerivativesAndFinancialInstruments" xlink:type="simple"/>
<link:roleRef roleURI="http://www.pentair.com/role/DerivativesAndFinancialInstrumentsAdditionalInformationDetail" xlink:href="pnr-20180331.xsd#DerivativesAndFinancialInstrumentsAdditionalInformationDetail" xlink:type="simple"/>
<link:roleRef roleURI="http://www.pentair.com/role/DerivativesAndFinancialInstrumentsAssetsAndLiabilitiesMeasuredAtFairValueDetail" xlink:href="pnr-20180331.xsd#DerivativesAndFinancialInstrumentsAssetsAndLiabilitiesMeasuredAtFairValueDetail" xlink:type="simple"/>
<link:roleRef roleURI="http://www.pentair.com/role/DerivativesAndFinancialInstrumentsRecordedAmountsAndEstimatedFairValuesOfLongTermDebtAndDerivativeFinancialInstrumentsDetail" xlink:href="pnr-20180331.xsd#DerivativesAndFinancialInstrumentsRecordedAmountsAndEstimatedFairValuesOfLongTermDebtAndDerivativeFinancialInstrumentsDetail" xlink:type="simple"/>
<link:roleRef roleURI="http://www.pentair.com/role/DerivativesAndFinancialInstrumentsTables" xlink:href="pnr-20180331.xsd#DerivativesAndFinancialInstrumentsTables" xlink:type="simple"/>
<link:roleRef roleURI="http://www.pentair.com/role/DiscontinuedOperations" xlink:href="pnr-20180331.xsd#DiscontinuedOperations" xlink:type="simple"/>
<link:roleRef roleURI="http://www.pentair.com/role/DiscontinuedOperationsAdditionalInformationDetails" xlink:href="pnr-20180331.xsd#DiscontinuedOperationsAdditionalInformationDetails" xlink:type="simple"/>
<link:roleRef roleURI="http://www.pentair.com/role/DiscontinuedOperationsBalanceSheetDetails" xlink:href="pnr-20180331.xsd#DiscontinuedOperationsBalanceSheetDetails" xlink:type="simple"/>
<link:roleRef roleURI="http://www.pentair.com/role/DiscontinuedOperationsIncomeStatementDetails" xlink:href="pnr-20180331.xsd#DiscontinuedOperationsIncomeStatementDetails" xlink:type="simple"/>
<link:roleRef roleURI="http://www.pentair.com/role/DiscontinuedOperationsTables" xlink:href="pnr-20180331.xsd#DiscontinuedOperationsTables" xlink:type="simple"/>
<link:roleRef roleURI="http://www.pentair.com/role/DocumentAndEntityInformation" xlink:href="pnr-20180331.xsd#DocumentAndEntityInformation" xlink:type="simple"/>
<link:roleRef roleURI="http://www.pentair.com/role/EarningsPerShare" xlink:href="pnr-20180331.xsd#EarningsPerShare" xlink:type="simple"/>
<link:roleRef roleURI="http://www.pentair.com/role/EarningsPerShareBasicAndDilutedEarningsPerShareDetail" xlink:href="pnr-20180331.xsd#EarningsPerShareBasicAndDilutedEarningsPerShareDetail" xlink:type="simple"/>
<link:roleRef roleURI="http://www.pentair.com/role/EarningsPerShareTables" xlink:href="pnr-20180331.xsd#EarningsPerShareTables" xlink:type="simple"/>
<link:roleRef roleURI="http://www.pentair.com/role/FinancialStatementsOfParentCompanyGuarantor" xlink:href="pnr-20180331.xsd#FinancialStatementsOfParentCompanyGuarantor" xlink:type="simple"/>
<link:roleRef roleURI="http://www.pentair.com/role/FinancialStatementsOfParentCompanyGuarantorAdditionalInformationDetail" xlink:href="pnr-20180331.xsd#FinancialStatementsOfParentCompanyGuarantorAdditionalInformationDetail" xlink:type="simple"/>
<link:roleRef roleURI="http://www.pentair.com/role/FinancialStatementsOfParentCompanyGuarantorCondensedConsolidatingBalanceSheetDetail" xlink:href="pnr-20180331.xsd#FinancialStatementsOfParentCompanyGuarantorCondensedConsolidatingBalanceSheetDetail" xlink:type="simple"/>
<link:roleRef roleURI="http://www.pentair.com/role/FinancialStatementsOfParentCompanyGuarantorCondensedConsolidatingStatementOfCashFlowsDetail" xlink:href="pnr-20180331.xsd#FinancialStatementsOfParentCompanyGuarantorCondensedConsolidatingStatementOfCashFlowsDetail" xlink:type="simple"/>
<link:roleRef roleURI="http://www.pentair.com/role/FinancialStatementsOfParentCompanyGuarantorCondensedConsolidatingStatementOfOperationsAndComprehensiveIncomeLossDetail" xlink:href="pnr-20180331.xsd#FinancialStatementsOfParentCompanyGuarantorCondensedConsolidatingStatementOfOperationsAndComprehensiveIncomeLossDetail" xlink:type="simple"/>
<link:roleRef roleURI="http://www.pentair.com/role/FinancialStatementsOfParentCompanyGuarantorTables" xlink:href="pnr-20180331.xsd#FinancialStatementsOfParentCompanyGuarantorTables" xlink:type="simple"/>
<link:roleRef roleURI="http://www.pentair.com/role/GoodwillAndOtherIdentifiableIntangibleAssets" xlink:href="pnr-20180331.xsd#GoodwillAndOtherIdentifiableIntangibleAssets" xlink:type="simple"/>
<link:roleRef roleURI="http://www.pentair.com/role/GoodwillAndOtherIdentifiableIntangibleAssetsAdditionalInformationDetail" xlink:href="pnr-20180331.xsd#GoodwillAndOtherIdentifiableIntangibleAssetsAdditionalInformationDetail" xlink:type="simple"/>
<link:roleRef roleURI="http://www.pentair.com/role/GoodwillAndOtherIdentifiableIntangibleAssetsChangesInCarryingAmountOfGoodwillBySegmentDetail" xlink:href="pnr-20180331.xsd#GoodwillAndOtherIdentifiableIntangibleAssetsChangesInCarryingAmountOfGoodwillBySegmentDetail" xlink:type="simple"/>
<link:roleRef roleURI="http://www.pentair.com/role/GoodwillAndOtherIdentifiableIntangibleAssetsDetailOfIdentifiableIntangibleAssetsDetail" xlink:href="pnr-20180331.xsd#GoodwillAndOtherIdentifiableIntangibleAssetsDetailOfIdentifiableIntangibleAssetsDetail" xlink:type="simple"/>
<link:roleRef roleURI="http://www.pentair.com/role/GoodwillAndOtherIdentifiableIntangibleAssetsEstimatedFutureAmortizationExpenseForIdentifiableIntangibleAssetsDetail" xlink:href="pnr-20180331.xsd#GoodwillAndOtherIdentifiableIntangibleAssetsEstimatedFutureAmortizationExpenseForIdentifiableIntangibleAssetsDetail" xlink:type="simple"/>
<link:roleRef roleURI="http://www.pentair.com/role/GoodwillAndOtherIdentifiableIntangibleAssetsTables" xlink:href="pnr-20180331.xsd#GoodwillAndOtherIdentifiableIntangibleAssetsTables" xlink:type="simple"/>
<link:roleRef roleURI="http://www.pentair.com/role/IncomeTaxes" xlink:href="pnr-20180331.xsd#IncomeTaxes" xlink:type="simple"/>
<link:roleRef roleURI="http://www.pentair.com/role/IncomeTaxesAdditionalInformationDetail" xlink:href="pnr-20180331.xsd#IncomeTaxesAdditionalInformationDetail" xlink:type="simple"/>
<link:roleRef roleURI="http://www.pentair.com/role/Restructuring" xlink:href="pnr-20180331.xsd#Restructuring" xlink:type="simple"/>
<link:roleRef roleURI="http://www.pentair.com/role/RestructuringAdditionalInformationDetail" xlink:href="pnr-20180331.xsd#RestructuringAdditionalInformationDetail" xlink:type="simple"/>
<link:roleRef roleURI="http://www.pentair.com/role/RestructuringRestructuringAccrualActivityRecordedOnCondensedConsolidatedBalanceSheetsDetail" xlink:href="pnr-20180331.xsd#RestructuringRestructuringAccrualActivityRecordedOnCondensedConsolidatedBalanceSheetsDetail" xlink:type="simple"/>
<link:roleRef roleURI="http://www.pentair.com/role/RestructuringRestructuringRelatedCostsIncludedInSellingGeneralAdministrativeExpensesOnConsolidatedStatementsOfIncomeDetail" xlink:href="pnr-20180331.xsd#RestructuringRestructuringRelatedCostsIncludedInSellingGeneralAdministrativeExpensesOnConsolidatedStatementsOfIncomeDetail" xlink:type="simple"/>
<link:roleRef roleURI="http://www.pentair.com/role/RestructuringTables" xlink:href="pnr-20180331.xsd#RestructuringTables" xlink:type="simple"/>
<link:roleRef roleURI="http://www.pentair.com/role/Revenue" xlink:href="pnr-20180331.xsd#Revenue" xlink:type="simple"/>
<link:roleRef roleURI="http://www.pentair.com/role/RevenueAdditionalInformationDetails" xlink:href="pnr-20180331.xsd#RevenueAdditionalInformationDetails" xlink:type="simple"/>
<link:roleRef roleURI="http://www.pentair.com/role/RevenueGeographicNetSalesInformationBySegmentDetails" xlink:href="pnr-20180331.xsd#RevenueGeographicNetSalesInformationBySegmentDetails" xlink:type="simple"/>
<link:roleRef roleURI="http://www.pentair.com/role/RevenuePerformanceObligationsDetails" xlink:href="pnr-20180331.xsd#RevenuePerformanceObligationsDetails" xlink:type="simple"/>
<link:roleRef roleURI="http://www.pentair.com/role/RevenueScheduleOfContractAssetsAndLiabilitiesDetails" xlink:href="pnr-20180331.xsd#RevenueScheduleOfContractAssetsAndLiabilitiesDetails" xlink:type="simple"/>
<link:roleRef roleURI="http://www.pentair.com/role/RevenueTables" xlink:href="pnr-20180331.xsd#RevenueTables" xlink:type="simple"/>
<link:roleRef roleURI="http://www.pentair.com/role/SegmentInformation" xlink:href="pnr-20180331.xsd#SegmentInformation" xlink:type="simple"/>
<link:roleRef roleURI="http://www.pentair.com/role/SegmentInformationFinancialInformationByReportableSegmentDetail" xlink:href="pnr-20180331.xsd#SegmentInformationFinancialInformationByReportableSegmentDetail" xlink:type="simple"/>
<link:roleRef roleURI="http://www.pentair.com/role/SegmentInformationReconciliationOfOperatingProfitLossFromSegmentsToConsolidatedDetails" xlink:href="pnr-20180331.xsd#SegmentInformationReconciliationOfOperatingProfitLossFromSegmentsToConsolidatedDetails" xlink:type="simple"/>
<link:roleRef roleURI="http://www.pentair.com/role/SegmentInformationTables" xlink:href="pnr-20180331.xsd#SegmentInformationTables" xlink:type="simple"/>
<link:roleRef roleURI="http://www.pentair.com/role/SharePlans" xlink:href="pnr-20180331.xsd#SharePlans" xlink:type="simple"/>
<link:roleRef roleURI="http://www.pentair.com/role/SharePlansAdditionalInformationDetail" xlink:href="pnr-20180331.xsd#SharePlansAdditionalInformationDetail" xlink:type="simple"/>
<link:roleRef roleURI="http://www.pentair.com/role/SharePlansTables" xlink:href="pnr-20180331.xsd#SharePlansTables" xlink:type="simple"/>
<link:roleRef roleURI="http://www.pentair.com/role/ShareholdersEquity" xlink:href="pnr-20180331.xsd#ShareholdersEquity" xlink:type="simple"/>
<link:roleRef roleURI="http://www.pentair.com/role/ShareholdersEquityAdditionalInformationDetail" xlink:href="pnr-20180331.xsd#ShareholdersEquityAdditionalInformationDetail" xlink:type="simple"/>
<link:roleRef roleURI="http://www.pentair.com/role/SupplementalBalanceSheetInformation" xlink:href="pnr-20180331.xsd#SupplementalBalanceSheetInformation" xlink:type="simple"/>
<link:roleRef roleURI="http://www.pentair.com/role/SupplementalBalanceSheetInformationDetail" xlink:href="pnr-20180331.xsd#SupplementalBalanceSheetInformationDetail" xlink:type="simple"/>
<link:roleRef roleURI="http://www.pentair.com/role/SupplementalBalanceSheetInformationTables" xlink:href="pnr-20180331.xsd#SupplementalBalanceSheetInformationTables" xlink:type="simple"/>
<link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/all" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#all" xlink:type="simple"/>
<link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#dimension-default" xlink:type="simple"/>
<link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#dimension-domain" xlink:type="simple"/>
<link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/domain-member" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#domain-member" xlink:type="simple"/>
<link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#hypercube-dimension" xlink:type="simple"/>
<link:definitionLink xlink:role="http://www.pentair.com/role/BasisOfPresentationAndResponsibilityForInterimFinancialStatements" xlink:type="extended"/>
<link:definitionLink xlink:role="http://www.pentair.com/role/BasisOfPresentationAndResponsibilityForInterimFinancialStatementsAdditionalInformationDetails" xlink:type="extended">
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_SubsequentEventLineItems" xlink:label="loc_us-gaap_SubsequentEventLineItems_310EF3AB537B5DA38926DC1534B3100A" xlink:type="locator"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_SubsequentEventTable" xlink:label="loc_us-gaap_SubsequentEventTable_25ADC064693BE929F88ADC1534AD0868" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_SubsequentEventLineItems_310EF3AB537B5DA38926DC1534B3100A" xlink:to="loc_us-gaap_SubsequentEventTable_25ADC064693BE929F88ADC1534AD0868" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_SubsequentEventTypeAxis" xlink:label="loc_us-gaap_SubsequentEventTypeAxis_ACFEF9DD912B8099F82BDC14B44B9E10" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_SubsequentEventTable_25ADC064693BE929F88ADC1534AD0868" xlink:to="loc_us-gaap_SubsequentEventTypeAxis_ACFEF9DD912B8099F82BDC14B44B9E10" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_SubsequentEventTypeDomain" xlink:label="loc_us-gaap_SubsequentEventTypeDomain_5D07F5A1FBA3FB20D025DC14B4524E16_default" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_SubsequentEventTypeAxis_ACFEF9DD912B8099F82BDC14B44B9E10" xlink:to="loc_us-gaap_SubsequentEventTypeDomain_5D07F5A1FBA3FB20D025DC14B4524E16_default" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_SubsequentEventTypeDomain" xlink:label="loc_us-gaap_SubsequentEventTypeDomain_5D07F5A1FBA3FB20D025DC14B4524E16" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_SubsequentEventTypeAxis_ACFEF9DD912B8099F82BDC14B44B9E10" xlink:to="loc_us-gaap_SubsequentEventTypeDomain_5D07F5A1FBA3FB20D025DC14B4524E16" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_SubsequentEventMember" xlink:label="loc_us-gaap_SubsequentEventMember_30ABDFC7249AFE0A3FD9DC14D158C43B" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsequentEventTypeDomain_5D07F5A1FBA3FB20D025DC14B4524E16" xlink:to="loc_us-gaap_SubsequentEventMember_30ABDFC7249AFE0A3FD9DC14D158C43B" xlink:type="arc"/>
<link:loc xlink:href="pnr-20180331.xsd#pnr_SpinoffTransactionEquityInterestsIssuedPerOrdinaryPredecessorShare" xlink:label="loc_pnr_SpinoffTransactionEquityInterestsIssuedPerOrdinaryPredecessorShare_83D33FEACAB815743486DC1439058E44" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsequentEventLineItems_310EF3AB537B5DA38926DC1534B3100A" xlink:to="loc_pnr_SpinoffTransactionEquityInterestsIssuedPerOrdinaryPredecessorShare_83D33FEACAB815743486DC1439058E44" xlink:type="arc"/>
<link:loc xlink:href="pnr-20180331.xsd#pnr_SpinoffTransactionNumberOfShareMarkets" xlink:label="loc_pnr_SpinoffTransactionNumberOfShareMarkets_239F42999BCF8B2AA49FDC1695A7084D" xlink:type="locator"/>
<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsequentEventLineItems_310EF3AB537B5DA38926DC1534B3100A" xlink:to="loc_pnr_SpinoffTransactionNumberOfShareMarkets_239F42999BCF8B2AA49FDC1695A7084D" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_NewAccountingPronouncementsOrChangeInAccountingPrincipleLineItems" xlink:label="loc_us-gaap_NewAccountingPronouncementsOrChangeInAccountingPrincipleLineItems_DCA3D6195EA92C4E117CDBCD9420A8A3" xlink:type="locator"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_NewAccountingPronouncementsOrChangeInAccountingPrincipleTable" xlink:label="loc_us-gaap_NewAccountingPronouncementsOrChangeInAccountingPrincipleTable_B9FE636A78E44A0384B0DBCD942008CF" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_NewAccountingPronouncementsOrChangeInAccountingPrincipleLineItems_DCA3D6195EA92C4E117CDBCD9420A8A3" xlink:to="loc_us-gaap_NewAccountingPronouncementsOrChangeInAccountingPrincipleTable_B9FE636A78E44A0384B0DBCD942008CF" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_StatementEquityComponentsAxis" xlink:label="loc_us-gaap_StatementEquityComponentsAxis_90978682F3FC4216BBC8DBCD942014C4" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_NewAccountingPronouncementsOrChangeInAccountingPrincipleTable_B9FE636A78E44A0384B0DBCD942008CF" xlink:to="loc_us-gaap_StatementEquityComponentsAxis_90978682F3FC4216BBC8DBCD942014C4" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_EquityComponentDomain" xlink:label="loc_us-gaap_EquityComponentDomain_00CC42AB1E08D8F7A5ECDBCD94207EAA_default" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_90978682F3FC4216BBC8DBCD942014C4" xlink:to="loc_us-gaap_EquityComponentDomain_00CC42AB1E08D8F7A5ECDBCD94207EAA_default" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_EquityComponentDomain" xlink:label="loc_us-gaap_EquityComponentDomain_00CC42AB1E08D8F7A5ECDBCD94207EAA" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_90978682F3FC4216BBC8DBCD942014C4" xlink:to="loc_us-gaap_EquityComponentDomain_00CC42AB1E08D8F7A5ECDBCD94207EAA" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_RetainedEarningsMember" xlink:label="loc_us-gaap_RetainedEarningsMember_03BDCCA86F9EC077F07CDBCD9420C3EA" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_00CC42AB1E08D8F7A5ECDBCD94207EAA" xlink:to="loc_us-gaap_RetainedEarningsMember_03BDCCA86F9EC077F07CDBCD9420C3EA" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_AdjustmentsForNewAccountingPronouncementsAxis" xlink:label="loc_us-gaap_AdjustmentsForNewAccountingPronouncementsAxis_CD7D0850F28F9AB6410FDBCD94208ABC" xlink:type="locator"/>
<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_NewAccountingPronouncementsOrChangeInAccountingPrincipleTable_B9FE636A78E44A0384B0DBCD942008CF" xlink:to="loc_us-gaap_AdjustmentsForNewAccountingPronouncementsAxis_CD7D0850F28F9AB6410FDBCD94208ABC" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_TypeOfAdoptionMember" xlink:label="loc_us-gaap_TypeOfAdoptionMember_E10ED9E5B011F21631DFDBCD94209513_default" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AdjustmentsForNewAccountingPronouncementsAxis_CD7D0850F28F9AB6410FDBCD94208ABC" xlink:to="loc_us-gaap_TypeOfAdoptionMember_E10ED9E5B011F21631DFDBCD94209513_default" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_TypeOfAdoptionMember" xlink:label="loc_us-gaap_TypeOfAdoptionMember_E10ED9E5B011F21631DFDBCD94209513" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AdjustmentsForNewAccountingPronouncementsAxis_CD7D0850F28F9AB6410FDBCD94208ABC" xlink:to="loc_us-gaap_TypeOfAdoptionMember_E10ED9E5B011F21631DFDBCD94209513" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_AccountingStandardsUpdate201409Member" xlink:label="loc_us-gaap_AccountingStandardsUpdate201409Member_8D78AB3ED8E285F39382DBCD9420998F" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TypeOfAdoptionMember_E10ED9E5B011F21631DFDBCD94209513" xlink:to="loc_us-gaap_AccountingStandardsUpdate201409Member_8D78AB3ED8E285F39382DBCD9420998F" xlink:type="arc"/>
<link:loc xlink:href="pnr-20180331.xsd#pnr_TaxCutsAndJobsActOf2017ReclassificationFromAociToRetainedEarnings" xlink:label="loc_pnr_TaxCutsAndJobsActOf2017ReclassificationFromAociToRetainedEarnings_4743E424B00D9D1CBFDBDBCD9420150F" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NewAccountingPronouncementsOrChangeInAccountingPrincipleLineItems_DCA3D6195EA92C4E117CDBCD9420A8A3" xlink:to="loc_pnr_TaxCutsAndJobsActOf2017ReclassificationFromAociToRetainedEarnings_4743E424B00D9D1CBFDBDBCD9420150F" xlink:type="arc"/>
<link:loc xlink:href="pnr-20180331.xsd#pnr_TaxCutsAndJobsActOf2017ChangeInTaxRateIncreaseDecreaseInPrepaidLongTermAsset" xlink:label="loc_pnr_TaxCutsAndJobsActOf2017ChangeInTaxRateIncreaseDecreaseInPrepaidLongTermAsset_39B81CEE6F7277BD7F9EDBCD9420C489" xlink:type="locator"/>
<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NewAccountingPronouncementsOrChangeInAccountingPrincipleLineItems_DCA3D6195EA92C4E117CDBCD9420A8A3" xlink:to="loc_pnr_TaxCutsAndJobsActOf2017ChangeInTaxRateIncreaseDecreaseInPrepaidLongTermAsset_39B81CEE6F7277BD7F9EDBCD9420C489" xlink:type="arc"/>
<link:loc xlink:href="pnr-20180331.xsd#pnr_TaxCutsAndJobsActOf2017ChangeInTaxRateDeferredTaxAssetIncomeTaxExpenseBenefit" xlink:label="loc_pnr_TaxCutsAndJobsActOf2017ChangeInTaxRateDeferredTaxAssetIncomeTaxExpenseBenefit_648B3FB2778391CF57DADBCD9420CF16" xlink:type="locator"/>
<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NewAccountingPronouncementsOrChangeInAccountingPrincipleLineItems_DCA3D6195EA92C4E117CDBCD9420A8A3" xlink:to="loc_pnr_TaxCutsAndJobsActOf2017ChangeInTaxRateDeferredTaxAssetIncomeTaxExpenseBenefit_648B3FB2778391CF57DADBCD9420CF16" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_CumulativeEffectOfNewAccountingPrincipleInPeriodOfAdoption" xlink:label="loc_us-gaap_CumulativeEffectOfNewAccountingPrincipleInPeriodOfAdoption_057B34052CA457F7C2C7DBCD9420D7F2" xlink:type="locator"/>
<link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NewAccountingPronouncementsOrChangeInAccountingPrincipleLineItems_DCA3D6195EA92C4E117CDBCD9420A8A3" xlink:to="loc_us-gaap_CumulativeEffectOfNewAccountingPrincipleInPeriodOfAdoption_057B34052CA457F7C2C7DBCD9420D7F2" xlink:type="arc"/>
</link:definitionLink>
<link:definitionLink xlink:role="http://www.pentair.com/role/BasisOfPresentationAndResponsibilityForInterimFinancialStatementsScheduleOfEffectOfAdoptionOfAsu201707Details" xlink:type="extended">
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_NewAccountingPronouncementsOrChangeInAccountingPrincipleLineItems" xlink:label="loc_us-gaap_NewAccountingPronouncementsOrChangeInAccountingPrincipleLineItems_51436D3687B08C11522DDBCC1E50171A" xlink:type="locator"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_NewAccountingPronouncementsOrChangeInAccountingPrincipleTable" xlink:label="loc_us-gaap_NewAccountingPronouncementsOrChangeInAccountingPrincipleTable_2A1A1A6CEEF80F2664EDDBCC1E4C5EFC" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_NewAccountingPronouncementsOrChangeInAccountingPrincipleLineItems_51436D3687B08C11522DDBCC1E50171A" xlink:to="loc_us-gaap_NewAccountingPronouncementsOrChangeInAccountingPrincipleTable_2A1A1A6CEEF80F2664EDDBCC1E4C5EFC" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_IncomeStatementLocationAxis" xlink:label="loc_us-gaap_IncomeStatementLocationAxis_38FF6ED797D5BBA4A550DBCCB7C6F729" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_NewAccountingPronouncementsOrChangeInAccountingPrincipleTable_2A1A1A6CEEF80F2664EDDBCC1E4C5EFC" xlink:to="loc_us-gaap_IncomeStatementLocationAxis_38FF6ED797D5BBA4A550DBCCB7C6F729" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_IncomeStatementLocationDomain" xlink:label="loc_us-gaap_IncomeStatementLocationDomain_525D17CF479E901A89B9DBCCB90019E6_default" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_IncomeStatementLocationAxis_38FF6ED797D5BBA4A550DBCCB7C6F729" xlink:to="loc_us-gaap_IncomeStatementLocationDomain_525D17CF479E901A89B9DBCCB90019E6_default" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_IncomeStatementLocationDomain" xlink:label="loc_us-gaap_IncomeStatementLocationDomain_525D17CF479E901A89B9DBCCB90019E6" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_IncomeStatementLocationAxis_38FF6ED797D5BBA4A550DBCCB7C6F729" xlink:to="loc_us-gaap_IncomeStatementLocationDomain_525D17CF479E901A89B9DBCCB90019E6" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_SellingGeneralAndAdministrativeExpensesMember" xlink:label="loc_us-gaap_SellingGeneralAndAdministrativeExpensesMember_82075066A9DC9E532E48DBCCF02B783D" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementLocationDomain_525D17CF479E901A89B9DBCCB90019E6" xlink:to="loc_us-gaap_SellingGeneralAndAdministrativeExpensesMember_82075066A9DC9E532E48DBCCF02B783D" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_OperatingIncomeLossMember" xlink:label="loc_us-gaap_OperatingIncomeLossMember_DD2D40D6181FFC91933FDBCD25ECB80E" xlink:type="locator"/>
<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementLocationDomain_525D17CF479E901A89B9DBCCB90019E6" xlink:to="loc_us-gaap_OperatingIncomeLossMember_DD2D40D6181FFC91933FDBCD25ECB80E" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_OtherExpenseMember" xlink:label="loc_us-gaap_OtherExpenseMember_E8A539C99DD6EB62B5B6DBCD626A45AE" xlink:type="locator"/>
<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementLocationDomain_525D17CF479E901A89B9DBCCB90019E6" xlink:to="loc_us-gaap_OtherExpenseMember_E8A539C99DD6EB62B5B6DBCD626A45AE" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_StatementScenarioAxis" xlink:label="loc_us-gaap_StatementScenarioAxis_0F5FBA9B1317D327ED00DBCC1E4D5B3F" xlink:type="locator"/>
<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_NewAccountingPronouncementsOrChangeInAccountingPrincipleTable_2A1A1A6CEEF80F2664EDDBCC1E4C5EFC" xlink:to="loc_us-gaap_StatementScenarioAxis_0F5FBA9B1317D327ED00DBCC1E4D5B3F" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ScenarioUnspecifiedDomain" xlink:label="loc_us-gaap_ScenarioUnspecifiedDomain_7A45DDB7027543A6D1B3DBCC1E4D22C0_default" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementScenarioAxis_0F5FBA9B1317D327ED00DBCC1E4D5B3F" xlink:to="loc_us-gaap_ScenarioUnspecifiedDomain_7A45DDB7027543A6D1B3DBCC1E4D22C0_default" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ScenarioUnspecifiedDomain" xlink:label="loc_us-gaap_ScenarioUnspecifiedDomain_7A45DDB7027543A6D1B3DBCC1E4D22C0" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementScenarioAxis_0F5FBA9B1317D327ED00DBCC1E4D5B3F" xlink:to="loc_us-gaap_ScenarioUnspecifiedDomain_7A45DDB7027543A6D1B3DBCC1E4D22C0" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ScenarioPreviouslyReportedMember" xlink:label="loc_us-gaap_ScenarioPreviouslyReportedMember_3AF1DDA6E35176198D46DBCC1E4DF5CB" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScenarioUnspecifiedDomain_7A45DDB7027543A6D1B3DBCC1E4D22C0" xlink:to="loc_us-gaap_ScenarioPreviouslyReportedMember_3AF1DDA6E35176198D46DBCC1E4DF5CB" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ScenarioAdjustmentMember" xlink:label="loc_us-gaap_ScenarioAdjustmentMember_63BE6AA08CCD6393DDF1DBCC1E4F300E" xlink:type="locator"/>
<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScenarioUnspecifiedDomain_7A45DDB7027543A6D1B3DBCC1E4D22C0" xlink:to="loc_us-gaap_ScenarioAdjustmentMember_63BE6AA08CCD6393DDF1DBCC1E4F300E" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_AdjustmentsForNewAccountingPronouncementsAxis" xlink:label="loc_us-gaap_AdjustmentsForNewAccountingPronouncementsAxis_767E58686A20A69F3D9FDBCC1E4F07D5" xlink:type="locator"/>
<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_NewAccountingPronouncementsOrChangeInAccountingPrincipleTable_2A1A1A6CEEF80F2664EDDBCC1E4C5EFC" xlink:to="loc_us-gaap_AdjustmentsForNewAccountingPronouncementsAxis_767E58686A20A69F3D9FDBCC1E4F07D5" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_TypeOfAdoptionMember" xlink:label="loc_us-gaap_TypeOfAdoptionMember_37AE349DEFEECCFC5C74DBCC1E50ED94_default" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AdjustmentsForNewAccountingPronouncementsAxis_767E58686A20A69F3D9FDBCC1E4F07D5" xlink:to="loc_us-gaap_TypeOfAdoptionMember_37AE349DEFEECCFC5C74DBCC1E50ED94_default" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_TypeOfAdoptionMember" xlink:label="loc_us-gaap_TypeOfAdoptionMember_37AE349DEFEECCFC5C74DBCC1E50ED94" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AdjustmentsForNewAccountingPronouncementsAxis_767E58686A20A69F3D9FDBCC1E4F07D5" xlink:to="loc_us-gaap_TypeOfAdoptionMember_37AE349DEFEECCFC5C74DBCC1E50ED94" xlink:type="arc"/>
<link:loc xlink:href="pnr-20180331.xsd#pnr_AccountingStandardsUpdate201707Member" xlink:label="loc_pnr_AccountingStandardsUpdate201707Member_CA13E58580B6C25E8302DBCC1E50ABF7" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TypeOfAdoptionMember_37AE349DEFEECCFC5C74DBCC1E50ED94" xlink:to="loc_pnr_AccountingStandardsUpdate201707Member_CA13E58580B6C25E8302DBCC1E50ABF7" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DefinedBenefitPlanNetPeriodicBenefitCost" xlink:label="loc_us-gaap_DefinedBenefitPlanNetPeriodicBenefitCost_32D2DB18A0609EEECBE0DBCC20E920A0" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NewAccountingPronouncementsOrChangeInAccountingPrincipleLineItems_51436D3687B08C11522DDBCC1E50171A" xlink:to="loc_us-gaap_DefinedBenefitPlanNetPeriodicBenefitCost_32D2DB18A0609EEECBE0DBCC20E920A0" xlink:type="arc"/>
</link:definitionLink>
<link:definitionLink xlink:role="http://www.pentair.com/role/BasisOfPresentationAndResponsibilityForInterimFinancialStatementsScheduleOfImpactOfAsc606OnCondensedConsolidatedBalanceSheetsDetails" xlink:type="extended">
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_RevenueInitialApplicationPeriodCumulativeEffectTransitionLineItems" xlink:label="loc_us-gaap_RevenueInitialApplicationPeriodCumulativeEffectTransitionLineItems_036A2F044A5349CD54CEDE73A5C143ED" xlink:type="locator"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_RevenueInitialApplicationPeriodCumulativeEffectTransitionTable" xlink:label="loc_us-gaap_RevenueInitialApplicationPeriodCumulativeEffectTransitionTable_217AC32069C60CAAB237DE73A5C03C03" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_RevenueInitialApplicationPeriodCumulativeEffectTransitionLineItems_036A2F044A5349CD54CEDE73A5C143ED" xlink:to="loc_us-gaap_RevenueInitialApplicationPeriodCumulativeEffectTransitionTable_217AC32069C60CAAB237DE73A5C03C03" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_InitialApplicationPeriodCumulativeEffectTransitionAxis" xlink:label="loc_us-gaap_InitialApplicationPeriodCumulativeEffectTransitionAxis_CE233A941349E994F250DE73A5C01A57" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_RevenueInitialApplicationPeriodCumulativeEffectTransitionTable_217AC32069C60CAAB237DE73A5C03C03" xlink:to="loc_us-gaap_InitialApplicationPeriodCumulativeEffectTransitionAxis_CE233A941349E994F250DE73A5C01A57" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_InitialApplicationPeriodCumulativeEffectTransitionDomain" xlink:label="loc_us-gaap_InitialApplicationPeriodCumulativeEffectTransitionDomain_992B68C48691A5B21FA6DE73A5C06D39_default" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_InitialApplicationPeriodCumulativeEffectTransitionAxis_CE233A941349E994F250DE73A5C01A57" xlink:to="loc_us-gaap_InitialApplicationPeriodCumulativeEffectTransitionDomain_992B68C48691A5B21FA6DE73A5C06D39_default" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_InitialApplicationPeriodCumulativeEffectTransitionDomain" xlink:label="loc_us-gaap_InitialApplicationPeriodCumulativeEffectTransitionDomain_992B68C48691A5B21FA6DE73A5C06D39" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_InitialApplicationPeriodCumulativeEffectTransitionAxis_CE233A941349E994F250DE73A5C01A57" xlink:to="loc_us-gaap_InitialApplicationPeriodCumulativeEffectTransitionDomain_992B68C48691A5B21FA6DE73A5C06D39" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_CalculatedUnderRevenueGuidanceInEffectBeforeTopic606Member" xlink:label="loc_us-gaap_CalculatedUnderRevenueGuidanceInEffectBeforeTopic606Member_4BDC31174D578F07D60CDE73A5C0BD7A" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InitialApplicationPeriodCumulativeEffectTransitionDomain_992B68C48691A5B21FA6DE73A5C06D39" xlink:to="loc_us-gaap_CalculatedUnderRevenueGuidanceInEffectBeforeTopic606Member_4BDC31174D578F07D60CDE73A5C0BD7A" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DifferenceBetweenRevenueGuidanceInEffectBeforeAndAfterTopic606Member" xlink:label="loc_us-gaap_DifferenceBetweenRevenueGuidanceInEffectBeforeAndAfterTopic606Member_41A06EAA3744C1D63999DE73A5C10C17" xlink:type="locator"/>
<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InitialApplicationPeriodCumulativeEffectTransitionDomain_992B68C48691A5B21FA6DE73A5C06D39" xlink:to="loc_us-gaap_DifferenceBetweenRevenueGuidanceInEffectBeforeAndAfterTopic606Member_41A06EAA3744C1D63999DE73A5C10C17" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_AdjustmentsForNewAccountingPronouncementsAxis" xlink:label="loc_us-gaap_AdjustmentsForNewAccountingPronouncementsAxis_56F22596F2E01F7809E1DE73A5C1E9B3" xlink:type="locator"/>
<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_RevenueInitialApplicationPeriodCumulativeEffectTransitionTable_217AC32069C60CAAB237DE73A5C03C03" xlink:to="loc_us-gaap_AdjustmentsForNewAccountingPronouncementsAxis_56F22596F2E01F7809E1DE73A5C1E9B3" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_TypeOfAdoptionMember" xlink:label="loc_us-gaap_TypeOfAdoptionMember_A76F7C4040979B8A37EADE73A5C1F494_default" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AdjustmentsForNewAccountingPronouncementsAxis_56F22596F2E01F7809E1DE73A5C1E9B3" xlink:to="loc_us-gaap_TypeOfAdoptionMember_A76F7C4040979B8A37EADE73A5C1F494_default" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_TypeOfAdoptionMember" xlink:label="loc_us-gaap_TypeOfAdoptionMember_A76F7C4040979B8A37EADE73A5C1F494" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AdjustmentsForNewAccountingPronouncementsAxis_56F22596F2E01F7809E1DE73A5C1E9B3" xlink:to="loc_us-gaap_TypeOfAdoptionMember_A76F7C4040979B8A37EADE73A5C1F494" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_AccountingStandardsUpdate201616Member" xlink:label="loc_us-gaap_AccountingStandardsUpdate201616Member_67F7869736EE0BC59017DE73A5C19F7D" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TypeOfAdoptionMember_A76F7C4040979B8A37EADE73A5C1F494" xlink:to="loc_us-gaap_AccountingStandardsUpdate201616Member_67F7869736EE0BC59017DE73A5C19F7D" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_AccountingStandardsUpdate201409Member" xlink:label="loc_us-gaap_AccountingStandardsUpdate201409Member_63D263C724BD1391615BDE73A5C1C332" xlink:type="locator"/>
<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TypeOfAdoptionMember_A76F7C4040979B8A37EADE73A5C1F494" xlink:to="loc_us-gaap_AccountingStandardsUpdate201409Member_63D263C724BD1391615BDE73A5C1C332" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_AssetsAbstract" xlink:label="loc_us-gaap_AssetsAbstract_051210E9A4CC6BDC73C5DE73A5C1517F" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RevenueInitialApplicationPeriodCumulativeEffectTransitionLineItems_036A2F044A5349CD54CEDE73A5C143ED" xlink:to="loc_us-gaap_AssetsAbstract_051210E9A4CC6BDC73C5DE73A5C1517F" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_AccountsAndNotesReceivableNet" xlink:label="loc_us-gaap_AccountsAndNotesReceivableNet_27519B3238CA7126A4FBDE73A5C12634" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_051210E9A4CC6BDC73C5DE73A5C1517F" xlink:to="loc_us-gaap_AccountsAndNotesReceivableNet_27519B3238CA7126A4FBDE73A5C12634" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_InventoryNet" xlink:label="loc_us-gaap_InventoryNet_16A518306782A58C67B4DE73A5C1D76D" xlink:type="locator"/>
<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_051210E9A4CC6BDC73C5DE73A5C1517F" xlink:to="loc_us-gaap_InventoryNet_16A518306782A58C67B4DE73A5C1D76D" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_OtherAssetsCurrent" xlink:label="loc_us-gaap_OtherAssetsCurrent_68935455AFF44C1648AFDE73A5C1735B" xlink:type="locator"/>
<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_051210E9A4CC6BDC73C5DE73A5C1517F" xlink:to="loc_us-gaap_OtherAssetsCurrent_68935455AFF44C1648AFDE73A5C1735B" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_OtherAssetsNoncurrent" xlink:label="loc_us-gaap_OtherAssetsNoncurrent_9FBD0A04214827AF32A6DE73A5C1659E" xlink:type="locator"/>
<link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_051210E9A4CC6BDC73C5DE73A5C1517F" xlink:to="loc_us-gaap_OtherAssetsNoncurrent_9FBD0A04214827AF32A6DE73A5C1659E" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_LiabilitiesAbstract" xlink:label="loc_us-gaap_LiabilitiesAbstract_618A9CF4437565CF33ABDE73A5C103D8" xlink:type="locator"/>
<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RevenueInitialApplicationPeriodCumulativeEffectTransitionLineItems_036A2F044A5349CD54CEDE73A5C143ED" xlink:to="loc_us-gaap_LiabilitiesAbstract_618A9CF4437565CF33ABDE73A5C103D8" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_OtherAccruedLiabilitiesCurrent" xlink:label="loc_us-gaap_OtherAccruedLiabilitiesCurrent_B50ECF475A624CAAD42FDE73A5C16CE9" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAbstract_618A9CF4437565CF33ABDE73A5C103D8" xlink:to="loc_us-gaap_OtherAccruedLiabilitiesCurrent_B50ECF475A624CAAD42FDE73A5C16CE9" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DeferredTaxLiabilitiesNoncurrent" xlink:label="loc_us-gaap_DeferredTaxLiabilitiesNoncurrent_E9B5154E6FADB8BF6D0CDE73A5C1217A" xlink:type="locator"/>
<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAbstract_618A9CF4437565CF33ABDE73A5C103D8" xlink:to="loc_us-gaap_DeferredTaxLiabilitiesNoncurrent_E9B5154E6FADB8BF6D0CDE73A5C1217A" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_EquityAbstract" xlink:label="loc_us-gaap_EquityAbstract_AA5DF6A0C10008194B7FDE73A5C1F4DA" xlink:type="locator"/>
<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RevenueInitialApplicationPeriodCumulativeEffectTransitionLineItems_036A2F044A5349CD54CEDE73A5C143ED" xlink:to="loc_us-gaap_EquityAbstract_AA5DF6A0C10008194B7FDE73A5C1F4DA" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_RetainedEarningsAccumulatedDeficit" xlink:label="loc_us-gaap_RetainedEarningsAccumulatedDeficit_BABC3E5DBD25D8B2B61CDE73A5C16DAA" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityAbstract_AA5DF6A0C10008194B7FDE73A5C1F4DA" xlink:to="loc_us-gaap_RetainedEarningsAccumulatedDeficit_BABC3E5DBD25D8B2B61CDE73A5C16DAA" xlink:type="arc"/>
</link:definitionLink>
<link:definitionLink xlink:role="http://www.pentair.com/role/BasisOfPresentationAndResponsibilityForInterimFinancialStatementsScheduleOfImpactOfAsc606OnConsolidatedStatementsOfOperationsAndComprehensiveIncomeLossDetails" xlink:type="extended">
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_RevenueInitialApplicationPeriodCumulativeEffectTransitionLineItems" xlink:label="loc_us-gaap_RevenueInitialApplicationPeriodCumulativeEffectTransitionLineItems_2D7D6BADBC0D5E65ACDAD0361BC5BB48" xlink:type="locator"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_RevenueInitialApplicationPeriodCumulativeEffectTransitionTable" xlink:label="loc_us-gaap_RevenueInitialApplicationPeriodCumulativeEffectTransitionTable_538D74BD0413B0C84E78D0361BC39D1F" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_RevenueInitialApplicationPeriodCumulativeEffectTransitionLineItems_2D7D6BADBC0D5E65ACDAD0361BC5BB48" xlink:to="loc_us-gaap_RevenueInitialApplicationPeriodCumulativeEffectTransitionTable_538D74BD0413B0C84E78D0361BC39D1F" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_InitialApplicationPeriodCumulativeEffectTransitionAxis" xlink:label="loc_us-gaap_InitialApplicationPeriodCumulativeEffectTransitionAxis_4EB33534E56D9DDCFA46D0361BC3E2CA" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_RevenueInitialApplicationPeriodCumulativeEffectTransitionTable_538D74BD0413B0C84E78D0361BC39D1F" xlink:to="loc_us-gaap_InitialApplicationPeriodCumulativeEffectTransitionAxis_4EB33534E56D9DDCFA46D0361BC3E2CA" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_InitialApplicationPeriodCumulativeEffectTransitionDomain" xlink:label="loc_us-gaap_InitialApplicationPeriodCumulativeEffectTransitionDomain_EB44E016BC1CC56219A4D0361BC31828_default" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_InitialApplicationPeriodCumulativeEffectTransitionAxis_4EB33534E56D9DDCFA46D0361BC3E2CA" xlink:to="loc_us-gaap_InitialApplicationPeriodCumulativeEffectTransitionDomain_EB44E016BC1CC56219A4D0361BC31828_default" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_InitialApplicationPeriodCumulativeEffectTransitionDomain" xlink:label="loc_us-gaap_InitialApplicationPeriodCumulativeEffectTransitionDomain_EB44E016BC1CC56219A4D0361BC31828" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_InitialApplicationPeriodCumulativeEffectTransitionAxis_4EB33534E56D9DDCFA46D0361BC3E2CA" xlink:to="loc_us-gaap_InitialApplicationPeriodCumulativeEffectTransitionDomain_EB44E016BC1CC56219A4D0361BC31828" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_CalculatedUnderRevenueGuidanceInEffectBeforeTopic606Member" xlink:label="loc_us-gaap_CalculatedUnderRevenueGuidanceInEffectBeforeTopic606Member_B8CFD2E4EA7FA2DA5DECD03888B5C08A" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InitialApplicationPeriodCumulativeEffectTransitionDomain_EB44E016BC1CC56219A4D0361BC31828" xlink:to="loc_us-gaap_CalculatedUnderRevenueGuidanceInEffectBeforeTopic606Member_B8CFD2E4EA7FA2DA5DECD03888B5C08A" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DifferenceBetweenRevenueGuidanceInEffectBeforeAndAfterTopic606Member" xlink:label="loc_us-gaap_DifferenceBetweenRevenueGuidanceInEffectBeforeAndAfterTopic606Member_183ECF746DD30D0BC4B0D0361BC3B9D8" xlink:type="locator"/>
<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InitialApplicationPeriodCumulativeEffectTransitionDomain_EB44E016BC1CC56219A4D0361BC31828" xlink:to="loc_us-gaap_DifferenceBetweenRevenueGuidanceInEffectBeforeAndAfterTopic606Member_183ECF746DD30D0BC4B0D0361BC3B9D8" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_AdjustmentsForNewAccountingPronouncementsAxis" xlink:label="loc_us-gaap_AdjustmentsForNewAccountingPronouncementsAxis_79030608008B030850EED0361BC5C533" xlink:type="locator"/>
<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_RevenueInitialApplicationPeriodCumulativeEffectTransitionTable_538D74BD0413B0C84E78D0361BC39D1F" xlink:to="loc_us-gaap_AdjustmentsForNewAccountingPronouncementsAxis_79030608008B030850EED0361BC5C533" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_TypeOfAdoptionMember" xlink:label="loc_us-gaap_TypeOfAdoptionMember_885155DB0CA8DDA58EC8D0361BC554B1_default" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AdjustmentsForNewAccountingPronouncementsAxis_79030608008B030850EED0361BC5C533" xlink:to="loc_us-gaap_TypeOfAdoptionMember_885155DB0CA8DDA58EC8D0361BC554B1_default" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_TypeOfAdoptionMember" xlink:label="loc_us-gaap_TypeOfAdoptionMember_885155DB0CA8DDA58EC8D0361BC554B1" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AdjustmentsForNewAccountingPronouncementsAxis_79030608008B030850EED0361BC5C533" xlink:to="loc_us-gaap_TypeOfAdoptionMember_885155DB0CA8DDA58EC8D0361BC554B1" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_AccountingStandardsUpdate201409Member" xlink:label="loc_us-gaap_AccountingStandardsUpdate201409Member_4F658B2F2908E33BEA36D0361BC5D2BB" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TypeOfAdoptionMember_885155DB0CA8DDA58EC8D0361BC554B1" xlink:to="loc_us-gaap_AccountingStandardsUpdate201409Member_4F658B2F2908E33BEA36D0361BC5D2BB" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_SalesRevenueNet" xlink:label="loc_us-gaap_SalesRevenueNet_38D8C6AA4361181494DFD0361BC58696" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RevenueInitialApplicationPeriodCumulativeEffectTransitionLineItems_2D7D6BADBC0D5E65ACDAD0361BC5BB48" xlink:to="loc_us-gaap_SalesRevenueNet_38D8C6AA4361181494DFD0361BC58696" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_CostOfGoodsSold" xlink:label="loc_us-gaap_CostOfGoodsSold_61B89968CE251D1E4DACD0361BC58874" xlink:type="locator"/>
<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RevenueInitialApplicationPeriodCumulativeEffectTransitionLineItems_2D7D6BADBC0D5E65ACDAD0361BC5BB48" xlink:to="loc_us-gaap_CostOfGoodsSold_61B89968CE251D1E4DACD0361BC58874" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_IncomeTaxExpenseBenefit" xlink:label="loc_us-gaap_IncomeTaxExpenseBenefit_76A5DDCD34739D807988D0361BC51BCD" xlink:type="locator"/>
<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RevenueInitialApplicationPeriodCumulativeEffectTransitionLineItems_2D7D6BADBC0D5E65ACDAD0361BC5BB48" xlink:to="loc_us-gaap_IncomeTaxExpenseBenefit_76A5DDCD34739D807988D0361BC51BCD" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_IncomeLossFromContinuingOperations" xlink:label="loc_us-gaap_IncomeLossFromContinuingOperations_EF2B3668EBFC70614F61D0361BC60D10" xlink:type="locator"/>
<link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RevenueInitialApplicationPeriodCumulativeEffectTransitionLineItems_2D7D6BADBC0D5E65ACDAD0361BC5BB48" xlink:to="loc_us-gaap_IncomeLossFromContinuingOperations_EF2B3668EBFC70614F61D0361BC60D10" xlink:type="arc"/>
</link:definitionLink>
<link:definitionLink xlink:role="http://www.pentair.com/role/BasisOfPresentationAndResponsibilityForInterimFinancialStatementsTables" xlink:type="extended"/>
<link:definitionLink xlink:role="http://www.pentair.com/role/BenefitPlans" xlink:type="extended"/>
<link:definitionLink xlink:role="http://www.pentair.com/role/BenefitPlansComponentsOfNetPeriodicBenefitCostDetail" xlink:type="extended">
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DefinedBenefitPlanDisclosureLineItems" xlink:label="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_F0413427E327B3671135CFF412417D73" xlink:type="locator"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable" xlink:label="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_3B3C18D8AC865C1A2221CFF4123BEDB4" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_F0413427E327B3671135CFF412417D73" xlink:to="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_3B3C18D8AC865C1A2221CFF4123BEDB4" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_RetirementPlanSponsorLocationAxis" xlink:label="loc_us-gaap_RetirementPlanSponsorLocationAxis_5BC4F9A3C342130CF488CFF41241C06B" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_3B3C18D8AC865C1A2221CFF4123BEDB4" xlink:to="loc_us-gaap_RetirementPlanSponsorLocationAxis_5BC4F9A3C342130CF488CFF41241C06B" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_RetirementPlanSponsorLocationDomain" xlink:label="loc_us-gaap_RetirementPlanSponsorLocationDomain_B8E62047BD19964FAC9CCFF412419A76_default" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationAxis_5BC4F9A3C342130CF488CFF41241C06B" xlink:to="loc_us-gaap_RetirementPlanSponsorLocationDomain_B8E62047BD19964FAC9CCFF412419A76_default" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_RetirementPlanSponsorLocationDomain" xlink:label="loc_us-gaap_RetirementPlanSponsorLocationDomain_B8E62047BD19964FAC9CCFF412419A76" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationAxis_5BC4F9A3C342130CF488CFF41241C06B" xlink:to="loc_us-gaap_RetirementPlanSponsorLocationDomain_B8E62047BD19964FAC9CCFF412419A76" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DomesticPlanMember" xlink:label="loc_us-gaap_DomesticPlanMember_8DE0094B3B968636007FCFF4124104EE" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationDomain_B8E62047BD19964FAC9CCFF412419A76" xlink:to="loc_us-gaap_DomesticPlanMember_8DE0094B3B968636007FCFF4124104EE" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ForeignPlanMember" xlink:label="loc_us-gaap_ForeignPlanMember_DF866FC41A86D6248856CFF4124125C0" xlink:type="locator"/>
<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationDomain_B8E62047BD19964FAC9CCFF412419A76" xlink:to="loc_us-gaap_ForeignPlanMember_DF866FC41A86D6248856CFF4124125C0" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DefinedBenefitPlanServiceCost" xlink:label="loc_us-gaap_DefinedBenefitPlanServiceCost_4B5BC4EC583028396C01CFF41241F0B4" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_F0413427E327B3671135CFF412417D73" xlink:to="loc_us-gaap_DefinedBenefitPlanServiceCost_4B5BC4EC583028396C01CFF41241F0B4" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DefinedBenefitPlanInterestCost" xlink:label="loc_us-gaap_DefinedBenefitPlanInterestCost_13101031934E686D6FCECFF41241C55C" xlink:type="locator"/>
<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_F0413427E327B3671135CFF412417D73" xlink:to="loc_us-gaap_DefinedBenefitPlanInterestCost_13101031934E686D6FCECFF41241C55C" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DefinedBenefitPlanExpectedReturnOnPlanAssets" xlink:label="loc_us-gaap_DefinedBenefitPlanExpectedReturnOnPlanAssets_243CC1051E484E0A9BACCFF412419197" xlink:type="locator"/>
<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_F0413427E327B3671135CFF412417D73" xlink:to="loc_us-gaap_DefinedBenefitPlanExpectedReturnOnPlanAssets_243CC1051E484E0A9BACCFF412419197" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DefinedBenefitPlanNetPeriodicBenefitCost" xlink:label="loc_us-gaap_DefinedBenefitPlanNetPeriodicBenefitCost_1D5DC6DBCBAA6D54F57FCFF41241268A" xlink:type="locator"/>
<link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_F0413427E327B3671135CFF412417D73" xlink:to="loc_us-gaap_DefinedBenefitPlanNetPeriodicBenefitCost_1D5DC6DBCBAA6D54F57FCFF41241268A" xlink:type="arc"/>
</link:definitionLink>
<link:definitionLink xlink:role="http://www.pentair.com/role/BenefitPlansTables" xlink:type="extended"/>
<link:definitionLink xlink:role="http://www.pentair.com/role/CommitmentsAndContingencies" xlink:type="extended">
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_StatementLineItems" xlink:label="loc_us-gaap_StatementLineItems_A637CCAF604C592AB08FB8CCC40BD09D" xlink:type="locator"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_StatementTable" xlink:label="loc_us-gaap_StatementTable_0ED01FFC6C815CF48BE8944ACD0A36F1" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_A637CCAF604C592AB08FB8CCC40BD09D" xlink:to="loc_us-gaap_StatementTable_0ED01FFC6C815CF48BE8944ACD0A36F1" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment"/>
<link:loc xlink:href="http://xbrl.sec.gov/dei/2014/dei-2014-01-31.xsd#dei_LegalEntityAxis" xlink:label="loc_dei_LegalEntityAxis_B41B86616A17524EA66C2F7D74F9C101" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_0ED01FFC6C815CF48BE8944ACD0A36F1" xlink:to="loc_dei_LegalEntityAxis_B41B86616A17524EA66C2F7D74F9C101" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.sec.gov/dei/2014/dei-2014-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_CDE0F83F51D8DE1E30DD57C2863F1E66_E3B43B43A3E7574E8DA0F8529D4EC1C5" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_B41B86616A17524EA66C2F7D74F9C101" xlink:to="loc_dei_EntityDomain_CDE0F83F51D8DE1E30DD57C2863F1E66_E3B43B43A3E7574E8DA0F8529D4EC1C5" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.sec.gov/dei/2014/dei-2014-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_CFB589B5F5355146BAD3725397D38B4B" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_B41B86616A17524EA66C2F7D74F9C101" xlink:to="loc_dei_EntityDomain_CFB589B5F5355146BAD3725397D38B4B" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_CommitmentsAndContingenciesDisclosureTextBlock" xlink:label="loc_us-gaap_CommitmentsAndContingenciesDisclosureTextBlock_0BAEB42FE5785AEEB6126F8367209B5E" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_A637CCAF604C592AB08FB8CCC40BD09D" xlink:to="loc_us-gaap_CommitmentsAndContingenciesDisclosureTextBlock_0BAEB42FE5785AEEB6126F8367209B5E" xlink:type="arc"/>
</link:definitionLink>
<link:definitionLink xlink:role="http://www.pentair.com/role/CommitmentsAndContingenciesAdditionalInformationDetail" xlink:type="extended"/>
<link:definitionLink xlink:role="http://www.pentair.com/role/CommitmentsAndContingenciesChangesInCarryingAmountOfServiceAndProductWarrantiesDetail" xlink:type="extended"/>
<link:definitionLink xlink:role="http://www.pentair.com/role/CommitmentsAndContingenciesTables" xlink:type="extended"/>
<link:definitionLink xlink:role="http://www.pentair.com/role/CondensedConsolidatedBalanceSheets" xlink:type="extended"/>
<link:definitionLink xlink:role="http://www.pentair.com/role/CondensedConsolidatedBalanceSheetsParenthetical" xlink:type="extended"/>
<link:definitionLink xlink:role="http://www.pentair.com/role/CondensedConsolidatedStatementsOfCashFlows" xlink:type="extended"/>
<link:definitionLink xlink:role="http://www.pentair.com/role/CondensedConsolidatedStatementsOfChangesInEquity" xlink:type="extended">
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_StatementLineItems" xlink:label="loc_us-gaap_StatementLineItems_8C27E5AADF3C0948943BDA59AFE2187C" xlink:type="locator"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_StatementTable" xlink:label="loc_us-gaap_StatementTable_CCA72D11142A9038619CDA59AFE13533" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_8C27E5AADF3C0948943BDA59AFE2187C" xlink:to="loc_us-gaap_StatementTable_CCA72D11142A9038619CDA59AFE13533" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_StatementEquityComponentsAxis" xlink:label="loc_us-gaap_StatementEquityComponentsAxis_6AAC9AB07D3E577B1A81DA59AFE225E1" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_CCA72D11142A9038619CDA59AFE13533" xlink:to="loc_us-gaap_StatementEquityComponentsAxis_6AAC9AB07D3E577B1A81DA59AFE225E1" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_EquityComponentDomain" xlink:label="loc_us-gaap_EquityComponentDomain_91B7D869EE6869EE42E4DA59AFE20B6A_default" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_6AAC9AB07D3E577B1A81DA59AFE225E1" xlink:to="loc_us-gaap_EquityComponentDomain_91B7D869EE6869EE42E4DA59AFE20B6A_default" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_EquityComponentDomain" xlink:label="loc_us-gaap_EquityComponentDomain_91B7D869EE6869EE42E4DA59AFE20B6A" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_6AAC9AB07D3E577B1A81DA59AFE225E1" xlink:to="loc_us-gaap_EquityComponentDomain_91B7D869EE6869EE42E4DA59AFE20B6A" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_CommonStockMember" xlink:label="loc_us-gaap_CommonStockMember_738D10C1C4BD39437005DA59AFE27EAC" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_91B7D869EE6869EE42E4DA59AFE20B6A" xlink:to="loc_us-gaap_CommonStockMember_738D10C1C4BD39437005DA59AFE27EAC" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_AdditionalPaidInCapitalMember" xlink:label="loc_us-gaap_AdditionalPaidInCapitalMember_0E41E4D89FFAA9B644C7DA59AFE24F9F" xlink:type="locator"/>
<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_91B7D869EE6869EE42E4DA59AFE20B6A" xlink:to="loc_us-gaap_AdditionalPaidInCapitalMember_0E41E4D89FFAA9B644C7DA59AFE24F9F" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_RetainedEarningsMember" xlink:label="loc_us-gaap_RetainedEarningsMember_2E1C7630CAE0720432B2DA59AFE25A7E" xlink:type="locator"/>
<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_91B7D869EE6869EE42E4DA59AFE20B6A" xlink:to="loc_us-gaap_RetainedEarningsMember_2E1C7630CAE0720432B2DA59AFE25A7E" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeMember" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_889C745399524C0D34D8DA59AFE267FF" xlink:type="locator"/>
<link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_91B7D869EE6869EE42E4DA59AFE20B6A" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_889C745399524C0D34D8DA59AFE267FF" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_IncreaseDecreaseInStockholdersEquityRollForward" xlink:label="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_2E6C6424894BFD48FBAFDA59AFE25FAD" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_8C27E5AADF3C0948943BDA59AFE2187C" xlink:to="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_2E6C6424894BFD48FBAFDA59AFE25FAD" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest" xlink:label="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_47DDFFFC9EF1C0D15C9ADA59AFE2E3A6" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_2E6C6424894BFD48FBAFDA59AFE25FAD" xlink:to="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_47DDFFFC9EF1C0D15C9ADA59AFE2E3A6" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_SharesOutstanding" xlink:label="loc_us-gaap_SharesOutstanding_CD575CDC48F28ED797A7DA59AFE27BC5" xlink:type="locator"/>
<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_2E6C6424894BFD48FBAFDA59AFE25FAD" xlink:to="loc_us-gaap_SharesOutstanding_CD575CDC48F28ED797A7DA59AFE27BC5" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ProfitLoss" xlink:label="loc_us-gaap_ProfitLoss_4F236FCF2354BAD20205DA59AFE2EED0" xlink:type="locator"/>
<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_2E6C6424894BFD48FBAFDA59AFE25FAD" xlink:to="loc_us-gaap_ProfitLoss_4F236FCF2354BAD20205DA59AFE2EED0" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_CumulativeEffectOfNewAccountingPrincipleInPeriodOfAdoption" xlink:label="loc_us-gaap_CumulativeEffectOfNewAccountingPrincipleInPeriodOfAdoption_1DFA08F39424AB3B630BDA59AFE20DE5" xlink:type="locator"/>
<link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_2E6C6424894BFD48FBAFDA59AFE25FAD" xlink:to="loc_us-gaap_CumulativeEffectOfNewAccountingPrincipleInPeriodOfAdoption_1DFA08F39424AB3B630BDA59AFE20DE5" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_OtherComprehensiveIncomeLossNetOfTax" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTax_B57B008DFF3BDF4B0EA9DA59AFE27597" xlink:type="locator"/>
<link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_2E6C6424894BFD48FBAFDA59AFE25FAD" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTax_B57B008DFF3BDF4B0EA9DA59AFE27597" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DividendsCommonStock" xlink:label="loc_us-gaap_DividendsCommonStock_86E8CB5D7165502D122FDA59AFE23B6C" xlink:type="locator"/>
<link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_2E6C6424894BFD48FBAFDA59AFE25FAD" xlink:to="loc_us-gaap_DividendsCommonStock_86E8CB5D7165502D122FDA59AFE23B6C" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_StockRepurchasedDuringPeriodValue" xlink:label="loc_us-gaap_StockRepurchasedDuringPeriodValue_427B5DE45BEF71A1901EDA59AFE37B06" xlink:type="locator"/>
<link:definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_2E6C6424894BFD48FBAFDA59AFE25FAD" xlink:to="loc_us-gaap_StockRepurchasedDuringPeriodValue_427B5DE45BEF71A1901EDA59AFE37B06" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_StockRepurchasedDuringPeriodShares" xlink:label="loc_us-gaap_StockRepurchasedDuringPeriodShares_C1F030B26ACA2BB09FA7DA59AFE3C7F4" xlink:type="locator"/>
<link:definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_2E6C6424894BFD48FBAFDA59AFE25FAD" xlink:to="loc_us-gaap_StockRepurchasedDuringPeriodShares_C1F030B26ACA2BB09FA7DA59AFE3C7F4" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_StockIssuedDuringPeriodValueStockOptionsExercised" xlink:label="loc_us-gaap_StockIssuedDuringPeriodValueStockOptionsExercised_FDD5DE270BE5B2AECFEFDA59AFE3AF1A" xlink:type="locator"/>
<link:definitionArc order="9" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_2E6C6424894BFD48FBAFDA59AFE25FAD" xlink:to="loc_us-gaap_StockIssuedDuringPeriodValueStockOptionsExercised_FDD5DE270BE5B2AECFEFDA59AFE3AF1A" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised" xlink:label="loc_us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised_1EE385D32B59052A1F58DA59AFE33096" xlink:type="locator"/>
<link:definitionArc order="10" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_2E6C6424894BFD48FBAFDA59AFE25FAD" xlink:to="loc_us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised_1EE385D32B59052A1F58DA59AFE33096" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_StockIssuedDuringPeriodSharesRestrictedStockAwardNetOfForfeitures" xlink:label="loc_us-gaap_StockIssuedDuringPeriodSharesRestrictedStockAwardNetOfForfeitures_326290C630CF5B2CBB05DA59AFE3ACFB" xlink:type="locator"/>
<link:definitionArc order="11" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_2E6C6424894BFD48FBAFDA59AFE25FAD" xlink:to="loc_us-gaap_StockIssuedDuringPeriodSharesRestrictedStockAwardNetOfForfeitures_326290C630CF5B2CBB05DA59AFE3ACFB" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_StockIssuedDuringPeriodValueRestrictedStockAwardNetOfForfeitures" xlink:label="loc_us-gaap_StockIssuedDuringPeriodValueRestrictedStockAwardNetOfForfeitures_412E2664101211B825A1DA59AFE34B94" xlink:type="locator"/>
<link:definitionArc order="12" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_2E6C6424894BFD48FBAFDA59AFE25FAD" xlink:to="loc_us-gaap_StockIssuedDuringPeriodValueRestrictedStockAwardNetOfForfeitures_412E2664101211B825A1DA59AFE34B94" xlink:type="arc"/>
<link:loc xlink:href="pnr-20180331.xsd#pnr_SharesSurrenderedByEmployees" xlink:label="loc_pnr_SharesSurrenderedByEmployees_F0E2EEFECD02C149F77ADA59AFE36052" xlink:type="locator"/>
<link:definitionArc order="13" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_2E6C6424894BFD48FBAFDA59AFE25FAD" xlink:to="loc_pnr_SharesSurrenderedByEmployees_F0E2EEFECD02C149F77ADA59AFE36052" xlink:type="arc"/>
<link:loc xlink:href="pnr-20180331.xsd#pnr_SharesSurrenderedByEmployeesShares" xlink:label="loc_pnr_SharesSurrenderedByEmployeesShares_1C28D861ED473BD158D7DA59AFE342BE" xlink:type="locator"/>
<link:definitionArc order="14" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_2E6C6424894BFD48FBAFDA59AFE25FAD" xlink:to="loc_pnr_SharesSurrenderedByEmployeesShares_1C28D861ED473BD158D7DA59AFE342BE" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue" xlink:label="loc_us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue_4F784CDA688EB2160356DA59AFE367F8" xlink:type="locator"/>
<link:definitionArc order="15" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_2E6C6424894BFD48FBAFDA59AFE25FAD" xlink:to="loc_us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue_4F784CDA688EB2160356DA59AFE367F8" xlink:type="arc"/>
</link:definitionLink>
<link:definitionLink xlink:role="http://www.pentair.com/role/CondensedConsolidatedStatementsOfOperationsAndComprehensiveIncomeLoss" xlink:type="extended"/>
<link:definitionLink xlink:role="http://www.pentair.com/role/CondensedConsolidatedStatementsOfOperationsAndComprehensiveIncomeParenthetical" xlink:type="extended"/>
<link:definitionLink xlink:role="http://www.pentair.com/role/Debt" xlink:type="extended"/>
<link:definitionLink xlink:role="http://www.pentair.com/role/DebtAdditionalInformationDetail" xlink:type="extended">
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DebtInstrumentLineItems" xlink:label="loc_us-gaap_DebtInstrumentLineItems_F4F7A7210EF5E2DAB334DC4C9113FF2B" xlink:type="locator"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DebtInstrumentTable" xlink:label="loc_us-gaap_DebtInstrumentTable_FC9D5908B9D65E88DFBADC4C9111C542" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DebtInstrumentLineItems_F4F7A7210EF5E2DAB334DC4C9113FF2B" xlink:to="loc_us-gaap_DebtInstrumentTable_FC9D5908B9D65E88DFBADC4C9111C542" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment"/>
<link:loc xlink:href="http://xbrl.sec.gov/dei/2014/dei-2014-01-31.xsd#dei_LegalEntityAxis" xlink:label="loc_dei_LegalEntityAxis_B9C063B677DFCF061891DC4C911187CD" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_FC9D5908B9D65E88DFBADC4C9111C542" xlink:to="loc_dei_LegalEntityAxis_B9C063B677DFCF061891DC4C911187CD" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.sec.gov/dei/2014/dei-2014-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_883D297381A81A85FAA5DC4C91118F4E_default" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_B9C063B677DFCF061891DC4C911187CD" xlink:to="loc_dei_EntityDomain_883D297381A81A85FAA5DC4C91118F4E_default" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.sec.gov/dei/2014/dei-2014-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_883D297381A81A85FAA5DC4C91118F4E" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_B9C063B677DFCF061891DC4C911187CD" xlink:to="loc_dei_EntityDomain_883D297381A81A85FAA5DC4C91118F4E" xlink:type="arc"/>
<link:loc xlink:href="pnr-20180331.xsd#pnr_NVentFinanceMember" xlink:label="loc_pnr_NVentFinanceMember_602440529BB5623956D0DC4C91125565" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityDomain_883D297381A81A85FAA5DC4C91118F4E" xlink:to="loc_pnr_NVentFinanceMember_602440529BB5623956D0DC4C91125565" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_StatementScenarioAxis" xlink:label="loc_us-gaap_StatementScenarioAxis_BBC86E99C9EE14827D3EDC4C9112E0B0" xlink:type="locator"/>
<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_FC9D5908B9D65E88DFBADC4C9111C542" xlink:to="loc_us-gaap_StatementScenarioAxis_BBC86E99C9EE14827D3EDC4C9112E0B0" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ScenarioUnspecifiedDomain" xlink:label="loc_us-gaap_ScenarioUnspecifiedDomain_8964D222AC57F4FD82BCDC4C9112482F_default" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementScenarioAxis_BBC86E99C9EE14827D3EDC4C9112E0B0" xlink:to="loc_us-gaap_ScenarioUnspecifiedDomain_8964D222AC57F4FD82BCDC4C9112482F_default" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ScenarioUnspecifiedDomain" xlink:label="loc_us-gaap_ScenarioUnspecifiedDomain_8964D222AC57F4FD82BCDC4C9112482F" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementScenarioAxis_BBC86E99C9EE14827D3EDC4C9112E0B0" xlink:to="loc_us-gaap_ScenarioUnspecifiedDomain_8964D222AC57F4FD82BCDC4C9112482F" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ScenarioForecastMember" xlink:label="loc_us-gaap_ScenarioForecastMember_90E3BA3CB802C15914A1DC4C9112FB2F" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScenarioUnspecifiedDomain_8964D222AC57F4FD82BCDC4C9112482F" xlink:to="loc_us-gaap_ScenarioForecastMember_90E3BA3CB802C15914A1DC4C9112FB2F" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_LineOfCreditFacilityAxis" xlink:label="loc_us-gaap_LineOfCreditFacilityAxis_BC5331D57FD841B4448ADC4C91129422" xlink:type="locator"/>
<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_FC9D5908B9D65E88DFBADC4C9111C542" xlink:to="loc_us-gaap_LineOfCreditFacilityAxis_BC5331D57FD841B4448ADC4C91129422" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_LineOfCreditFacilityLenderDomain" xlink:label="loc_us-gaap_LineOfCreditFacilityLenderDomain_ED0E0F41061C7EA8915FDC4C91126C5D_default" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LineOfCreditFacilityAxis_BC5331D57FD841B4448ADC4C91129422" xlink:to="loc_us-gaap_LineOfCreditFacilityLenderDomain_ED0E0F41061C7EA8915FDC4C91126C5D_default" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_LineOfCreditFacilityLenderDomain" xlink:label="loc_us-gaap_LineOfCreditFacilityLenderDomain_ED0E0F41061C7EA8915FDC4C91126C5D" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LineOfCreditFacilityAxis_BC5331D57FD841B4448ADC4C91129422" xlink:to="loc_us-gaap_LineOfCreditFacilityLenderDomain_ED0E0F41061C7EA8915FDC4C91126C5D" xlink:type="arc"/>
<link:loc xlink:href="pnr-20180331.xsd#pnr_OtherCreditFacilitiesMember" xlink:label="loc_pnr_OtherCreditFacilitiesMember_E6AA86D73A5105C24ECBDC4C91128865" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LineOfCreditFacilityLenderDomain_ED0E0F41061C7EA8915FDC4C91126C5D" xlink:to="loc_pnr_OtherCreditFacilitiesMember_E6AA86D73A5105C24ECBDC4C91128865" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_LongtermDebtTypeAxis" xlink:label="loc_us-gaap_LongtermDebtTypeAxis_6B8EE7E02BDFCF84A03CDC4C9112808B" xlink:type="locator"/>
<link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_FC9D5908B9D65E88DFBADC4C9111C542" xlink:to="loc_us-gaap_LongtermDebtTypeAxis_6B8EE7E02BDFCF84A03CDC4C9112808B" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_LongtermDebtTypeDomain" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_EE59C1B5A2E1B925E8F7DC4C9112D2B4_default" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_6B8EE7E02BDFCF84A03CDC4C9112808B" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_EE59C1B5A2E1B925E8F7DC4C9112D2B4_default" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_LongtermDebtTypeDomain" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_EE59C1B5A2E1B925E8F7DC4C9112D2B4" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_6B8EE7E02BDFCF84A03CDC4C9112808B" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_EE59C1B5A2E1B925E8F7DC4C9112D2B4" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_CommercialPaperMember" xlink:label="loc_us-gaap_CommercialPaperMember_28FBDEBD5592FA20CCE4DC4C9112FC2E" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_EE59C1B5A2E1B925E8F7DC4C9112D2B4" xlink:to="loc_us-gaap_CommercialPaperMember_28FBDEBD5592FA20CCE4DC4C9112FC2E" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_SeniorNotesMember" xlink:label="loc_us-gaap_SeniorNotesMember_CF58C8A4652EF928D6BFDC4C91124D4D" xlink:type="locator"/>
<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_EE59C1B5A2E1B925E8F7DC4C9112D2B4" xlink:to="loc_us-gaap_SeniorNotesMember_CF58C8A4652EF928D6BFDC4C91124D4D" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_CreditFacilityAxis" xlink:label="loc_us-gaap_CreditFacilityAxis_D9FA0D57DBF30BF218AFDC4C91121BC7" xlink:type="locator"/>
<link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_FC9D5908B9D65E88DFBADC4C9111C542" xlink:to="loc_us-gaap_CreditFacilityAxis_D9FA0D57DBF30BF218AFDC4C91121BC7" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_CreditFacilityDomain" xlink:label="loc_us-gaap_CreditFacilityDomain_73C01B1BC9D074395598DC4C911281B8_default" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_CreditFacilityAxis_D9FA0D57DBF30BF218AFDC4C91121BC7" xlink:to="loc_us-gaap_CreditFacilityDomain_73C01B1BC9D074395598DC4C911281B8_default" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_CreditFacilityDomain" xlink:label="loc_us-gaap_CreditFacilityDomain_73C01B1BC9D074395598DC4C911281B8" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_CreditFacilityAxis_D9FA0D57DBF30BF218AFDC4C91121BC7" xlink:to="loc_us-gaap_CreditFacilityDomain_73C01B1BC9D074395598DC4C911281B8" xlink:type="arc"/>
<link:loc xlink:href="pnr-20180331.xsd#pnr_TermLoanFacilityMember" xlink:label="loc_pnr_TermLoanFacilityMember_CC5F9193A57CF252F91DDC4C9112F4E2" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CreditFacilityDomain_73C01B1BC9D074395598DC4C911281B8" xlink:to="loc_pnr_TermLoanFacilityMember_CC5F9193A57CF252F91DDC4C9112F4E2" xlink:type="arc"/>
<link:loc xlink:href="pnr-20180331.xsd#pnr_SeniorUnsecuredRevolvingCreditFacilityMember" xlink:label="loc_pnr_SeniorUnsecuredRevolvingCreditFacilityMember_55EE24988D42925A41B0DC4C9112E559" xlink:type="locator"/>
<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CreditFacilityDomain_73C01B1BC9D074395598DC4C911281B8" xlink:to="loc_pnr_SeniorUnsecuredRevolvingCreditFacilityMember_55EE24988D42925A41B0DC4C9112E559" xlink:type="arc"/>
<link:loc xlink:href="pnr-20180331.xsd#pnr_OtherCreditFacilitiesMember" xlink:label="loc_pnr_OtherCreditFacilitiesMember_0FF64F0CEE7602730DDEDC4C91120BEA" xlink:type="locator"/>
<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CreditFacilityDomain_73C01B1BC9D074395598DC4C911281B8" xlink:to="loc_pnr_OtherCreditFacilitiesMember_0FF64F0CEE7602730DDEDC4C91120BEA" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_RevolvingCreditFacilityMember" xlink:label="loc_us-gaap_RevolvingCreditFacilityMember_6B35AD96552328EFD369DC4C91138AF6" xlink:type="locator"/>
<link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CreditFacilityDomain_73C01B1BC9D074395598DC4C911281B8" xlink:to="loc_us-gaap_RevolvingCreditFacilityMember_6B35AD96552328EFD369DC4C91138AF6" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_RangeAxis" xlink:label="loc_us-gaap_RangeAxis_872C9A41F007C0F5CCA5DC4C9113DD69" xlink:type="locator"/>
<link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_FC9D5908B9D65E88DFBADC4C9111C542" xlink:to="loc_us-gaap_RangeAxis_872C9A41F007C0F5CCA5DC4C9113DD69" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_RangeMember" xlink:label="loc_us-gaap_RangeMember_60F53E792A5711A8ED5BDC4C9113EC91_default" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RangeAxis_872C9A41F007C0F5CCA5DC4C9113DD69" xlink:to="loc_us-gaap_RangeMember_60F53E792A5711A8ED5BDC4C9113EC91_default" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_RangeMember" xlink:label="loc_us-gaap_RangeMember_60F53E792A5711A8ED5BDC4C9113EC91" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RangeAxis_872C9A41F007C0F5CCA5DC4C9113DD69" xlink:to="loc_us-gaap_RangeMember_60F53E792A5711A8ED5BDC4C9113EC91" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_MaximumMember" xlink:label="loc_us-gaap_MaximumMember_F3150B2BA9896D907FACDC4C91131429" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RangeMember_60F53E792A5711A8ED5BDC4C9113EC91" xlink:to="loc_us-gaap_MaximumMember_F3150B2BA9896D907FACDC4C91131429" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_MinimumMember" xlink:label="loc_us-gaap_MinimumMember_5F359BE5B409410E34DADC4C9113C58E" xlink:type="locator"/>
<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RangeMember_60F53E792A5711A8ED5BDC4C9113EC91" xlink:to="loc_us-gaap_MinimumMember_5F359BE5B409410E34DADC4C9113C58E" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DebtInstrumentAxis" xlink:label="loc_us-gaap_DebtInstrumentAxis_63203666715B0FE3F635DC4C9113FA4D" xlink:type="locator"/>
<link:definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_FC9D5908B9D65E88DFBADC4C9111C542" xlink:to="loc_us-gaap_DebtInstrumentAxis_63203666715B0FE3F635DC4C9113FA4D" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DebtInstrumentNameDomain" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_C59DA1F1C73A98098909DC4C91136023_default" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DebtInstrumentAxis_63203666715B0FE3F635DC4C9113FA4D" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_C59DA1F1C73A98098909DC4C91136023_default" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DebtInstrumentNameDomain" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_C59DA1F1C73A98098909DC4C91136023" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DebtInstrumentAxis_63203666715B0FE3F635DC4C9113FA4D" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_C59DA1F1C73A98098909DC4C91136023" xlink:type="arc"/>
<link:loc xlink:href="pnr-20180331.xsd#pnr_SeniorNotesThreePointNineFivePercentDueTwentyTwentyThreeMember" xlink:label="loc_pnr_SeniorNotesThreePointNineFivePercentDueTwentyTwentyThreeMember_6EA7BCDAFC3BDA7E7746DC4C9113F66B" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_C59DA1F1C73A98098909DC4C91136023" xlink:to="loc_pnr_SeniorNotesThreePointNineFivePercentDueTwentyTwentyThreeMember_6EA7BCDAFC3BDA7E7746DC4C9113F66B" xlink:type="arc"/>
<link:loc xlink:href="pnr-20180331.xsd#pnr_SeniorNotesFourPointFiveFivePercentDueTwentyTwentyEightMember" xlink:label="loc_pnr_SeniorNotesFourPointFiveFivePercentDueTwentyTwentyEightMember_2558FDA2318E9F70C80FDC4C91139D34" xlink:type="locator"/>
<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_C59DA1F1C73A98098909DC4C91136023" xlink:to="loc_pnr_SeniorNotesFourPointFiveFivePercentDueTwentyTwentyEightMember_2558FDA2318E9F70C80FDC4C91139D34" xlink:type="arc"/>
<link:loc xlink:href="pnr-20180331.xsd#pnr_SeniorNotesTwoPointNinePercentDueTwentyEighteenMember" xlink:label="loc_pnr_SeniorNotesTwoPointNinePercentDueTwentyEighteenMember_0A1103DD2F6C9946CD40DC4C911385F0" xlink:type="locator"/>
<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_C59DA1F1C73A98098909DC4C91136023" xlink:to="loc_pnr_SeniorNotesTwoPointNinePercentDueTwentyEighteenMember_0A1103DD2F6C9946CD40DC4C911385F0" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DebtInstrumentFaceAmount" xlink:label="loc_us-gaap_DebtInstrumentFaceAmount_6A7CF208CCBA82EB7A32DC4C911307DD" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_F4F7A7210EF5E2DAB334DC4C9113FF2B" xlink:to="loc_us-gaap_DebtInstrumentFaceAmount_6A7CF208CCBA82EB7A32DC4C911307DD" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DebtInstrumentInterestRateStatedPercentage" xlink:label="loc_us-gaap_DebtInstrumentInterestRateStatedPercentage_DEFA5FE2647E87A7367EDC4C9113F392" xlink:type="locator"/>
<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_F4F7A7210EF5E2DAB334DC4C9113FF2B" xlink:to="loc_us-gaap_DebtInstrumentInterestRateStatedPercentage_DEFA5FE2647E87A7367EDC4C9113F392" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DebtInstrumentTerm" xlink:label="loc_us-gaap_DebtInstrumentTerm_9F66A3FD1AC9E53A786CDC4C91135325" xlink:type="locator"/>
<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_F4F7A7210EF5E2DAB334DC4C9113FF2B" xlink:to="loc_us-gaap_DebtInstrumentTerm_9F66A3FD1AC9E53A786CDC4C91135325" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity" xlink:label="loc_us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity_A1BCAED510B602CFFFDBDC4C9113C313" xlink:type="locator"/>
<link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_F4F7A7210EF5E2DAB334DC4C9113FF2B" xlink:to="loc_us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity_A1BCAED510B602CFFFDBDC4C9113C313" xlink:type="arc"/>
<link:loc xlink:href="pnr-20180331.xsd#pnr_CreditFacilityAdditionalBorrowingCapacity" xlink:label="loc_pnr_CreditFacilityAdditionalBorrowingCapacity_E0752FAF627A49F7B65DDC4C911390BF" xlink:type="locator"/>
<link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_F4F7A7210EF5E2DAB334DC4C9113FF2B" xlink:to="loc_pnr_CreditFacilityAdditionalBorrowingCapacity_E0752FAF627A49F7B65DDC4C911390BF" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_LineOfCredit" xlink:label="loc_us-gaap_LineOfCredit_98FEB9DF3AC7D829BDD0DC4C9113F7CE" xlink:type="locator"/>
<link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_F4F7A7210EF5E2DAB334DC4C9113FF2B" xlink:to="loc_us-gaap_LineOfCredit_98FEB9DF3AC7D829BDD0DC4C9113F7CE" xlink:type="arc"/>
<link:loc xlink:href="pnr-20180331.xsd#pnr_PaymentsToAcquireProductiveAssetsExcessCashThreshold" xlink:label="loc_pnr_PaymentsToAcquireProductiveAssetsExcessCashThreshold_7D4213A4A31055D18B84DC4C9113CC8C" xlink:type="locator"/>
<link:definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_F4F7A7210EF5E2DAB334DC4C9113FF2B" xlink:to="loc_pnr_PaymentsToAcquireProductiveAssetsExcessCashThreshold_7D4213A4A31055D18B84DC4C9113CC8C" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_LineOfCreditFacilityCommitmentFeePercentage" xlink:label="loc_us-gaap_LineOfCreditFacilityCommitmentFeePercentage_4B6AA248D3FC7038F4C3DC4C91138F95" xlink:type="locator"/>
<link:definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_F4F7A7210EF5E2DAB334DC4C9113FF2B" xlink:to="loc_us-gaap_LineOfCreditFacilityCommitmentFeePercentage_4B6AA248D3FC7038F4C3DC4C91138F95" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_CommercialPaper" xlink:label="loc_us-gaap_CommercialPaper_7656446DD4E527B346CBDC4C9114002A" xlink:type="locator"/>
<link:definitionArc order="9" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_F4F7A7210EF5E2DAB334DC4C9113FF2B" xlink:to="loc_us-gaap_CommercialPaper_7656446DD4E527B346CBDC4C9114002A" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_BusinessCombinationAcquisitionRelatedCosts" xlink:label="loc_us-gaap_BusinessCombinationAcquisitionRelatedCosts_D5EB1124108BB5F1C843DC4C911497EB" xlink:type="locator"/>
<link:definitionArc order="10" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_F4F7A7210EF5E2DAB334DC4C9113FF2B" xlink:to="loc_us-gaap_BusinessCombinationAcquisitionRelatedCosts_D5EB1124108BB5F1C843DC4C911497EB" xlink:type="arc"/>
<link:loc xlink:href="pnr-20180331.xsd#pnr_DebtInstrumentLeverageRatioCovenant" xlink:label="loc_pnr_DebtInstrumentLeverageRatioCovenant_F16DCD9B389565CD35DDDC5751D89B8E" xlink:type="locator"/>
<link:definitionArc order="11" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_F4F7A7210EF5E2DAB334DC4C9113FF2B" xlink:to="loc_pnr_DebtInstrumentLeverageRatioCovenant_F16DCD9B389565CD35DDDC5751D89B8E" xlink:type="arc"/>
<link:loc xlink:href="pnr-20180331.xsd#pnr_DebtInstrumentLeverageRatioCovenantPeriod" xlink:label="loc_pnr_DebtInstrumentLeverageRatioCovenantPeriod_4AB4D7E01552C213B5F0DC4C9114A316" xlink:type="locator"/>
<link:definitionArc order="12" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_F4F7A7210EF5E2DAB334DC4C9113FF2B" xlink:to="loc_pnr_DebtInstrumentLeverageRatioCovenantPeriod_4AB4D7E01552C213B5F0DC4C9114A316" xlink:type="arc"/>
<link:loc xlink:href="pnr-20180331.xsd#pnr_DebtInstrumentEBITDARatioCovenant" xlink:label="loc_pnr_DebtInstrumentEBITDARatioCovenant_3184938857A0B79AE87ADC5828B42BEC" xlink:type="locator"/>
<link:definitionArc order="13" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_F4F7A7210EF5E2DAB334DC4C9113FF2B" xlink:to="loc_pnr_DebtInstrumentEBITDARatioCovenant_3184938857A0B79AE87ADC5828B42BEC" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_LineOfCreditFacilityRemainingBorrowingCapacity" xlink:label="loc_us-gaap_LineOfCreditFacilityRemainingBorrowingCapacity_2F39FAF9ED8E323457D9DC4C9114EF75" xlink:type="locator"/>
<link:definitionArc order="14" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_F4F7A7210EF5E2DAB334DC4C9113FF2B" xlink:to="loc_us-gaap_LineOfCreditFacilityRemainingBorrowingCapacity_2F39FAF9ED8E323457D9DC4C9114EF75" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DebtLongtermAndShorttermCombinedAmount" xlink:label="loc_us-gaap_DebtLongtermAndShorttermCombinedAmount_56B8F929BE682011D277DC4C9114193A" xlink:type="locator"/>
<link:definitionArc order="15" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_F4F7A7210EF5E2DAB334DC4C9113FF2B" xlink:to="loc_us-gaap_DebtLongtermAndShorttermCombinedAmount_56B8F929BE682011D277DC4C9114193A" xlink:type="arc"/>
</link:definitionLink>
<link:definitionLink xlink:role="http://www.pentair.com/role/DebtDebtAndAverageInterestRatesOnDebtOutstandingDetail" xlink:type="extended">
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DebtInstrumentLineItems" xlink:label="loc_us-gaap_DebtInstrumentLineItems_034CCFD6B13A8D5336CEDBCD932CA425" xlink:type="locator"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DebtInstrumentTable" xlink:label="loc_us-gaap_DebtInstrumentTable_DC0A09BC6EB4111C588FDBCD932537D1" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DebtInstrumentLineItems_034CCFD6B13A8D5336CEDBCD932CA425" xlink:to="loc_us-gaap_DebtInstrumentTable_DC0A09BC6EB4111C588FDBCD932537D1" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_CreditFacilityAxis" xlink:label="loc_us-gaap_CreditFacilityAxis_DBDEA4826E845034F308DBCD932A365B" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_DC0A09BC6EB4111C588FDBCD932537D1" xlink:to="loc_us-gaap_CreditFacilityAxis_DBDEA4826E845034F308DBCD932A365B" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_CreditFacilityDomain" xlink:label="loc_us-gaap_CreditFacilityDomain_398E65A0426923A66B30DBCD932B04C9_default" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_CreditFacilityAxis_DBDEA4826E845034F308DBCD932A365B" xlink:to="loc_us-gaap_CreditFacilityDomain_398E65A0426923A66B30DBCD932B04C9_default" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_CreditFacilityDomain" xlink:label="loc_us-gaap_CreditFacilityDomain_398E65A0426923A66B30DBCD932B04C9" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_CreditFacilityAxis_DBDEA4826E845034F308DBCD932A365B" xlink:to="loc_us-gaap_CreditFacilityDomain_398E65A0426923A66B30DBCD932B04C9" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_RevolvingCreditFacilityMember" xlink:label="loc_us-gaap_RevolvingCreditFacilityMember_23EE9903033AE8080082DBCD932B26A5" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CreditFacilityDomain_398E65A0426923A66B30DBCD932B04C9" xlink:to="loc_us-gaap_RevolvingCreditFacilityMember_23EE9903033AE8080082DBCD932B26A5" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DebtInstrumentAxis" xlink:label="loc_us-gaap_DebtInstrumentAxis_AC46167F32F2E53DA920DBCD932B8E54" xlink:type="locator"/>
<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_DC0A09BC6EB4111C588FDBCD932537D1" xlink:to="loc_us-gaap_DebtInstrumentAxis_AC46167F32F2E53DA920DBCD932B8E54" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DebtInstrumentNameDomain" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_F9F421A6ADC06EC17633DBCD932B2D80_default" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DebtInstrumentAxis_AC46167F32F2E53DA920DBCD932B8E54" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_F9F421A6ADC06EC17633DBCD932B2D80_default" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DebtInstrumentNameDomain" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_F9F421A6ADC06EC17633DBCD932B2D80" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DebtInstrumentAxis_AC46167F32F2E53DA920DBCD932B8E54" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_F9F421A6ADC06EC17633DBCD932B2D80" xlink:type="arc"/>
<link:loc xlink:href="pnr-20180331.xsd#pnr_LongTermRevolvingCreditFacilityMember" xlink:label="loc_pnr_LongTermRevolvingCreditFacilityMember_1F41557A064B69A9DA7DDBCD932BDE7A" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_F9F421A6ADC06EC17633DBCD932B2D80" xlink:to="loc_pnr_LongTermRevolvingCreditFacilityMember_1F41557A064B69A9DA7DDBCD932BDE7A" xlink:type="arc"/>
<link:loc xlink:href="pnr-20180331.xsd#pnr_SeniorNotesTwoPointNinePercentDueTwentyEighteenMember" xlink:label="loc_pnr_SeniorNotesTwoPointNinePercentDueTwentyEighteenMember_FFE5E04E70CC05FAE432DBCD932B2AC0" xlink:type="locator"/>
<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_F9F421A6ADC06EC17633DBCD932B2D80" xlink:to="loc_pnr_SeniorNotesTwoPointNinePercentDueTwentyEighteenMember_FFE5E04E70CC05FAE432DBCD932B2AC0" xlink:type="arc"/>
<link:loc xlink:href="pnr-20180331.xsd#pnr_SeniorNotesTwoPointSixFiveZeroPercentDueTwentyNineteenMember" xlink:label="loc_pnr_SeniorNotesTwoPointSixFiveZeroPercentDueTwentyNineteenMember_C269A7202A12B8FEF9BDDBCD932BA334" xlink:type="locator"/>
<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_F9F421A6ADC06EC17633DBCD932B2D80" xlink:to="loc_pnr_SeniorNotesTwoPointSixFiveZeroPercentDueTwentyNineteenMember_C269A7202A12B8FEF9BDDBCD932BA334" xlink:type="arc"/>
<link:loc xlink:href="pnr-20180331.xsd#pnr_SeniorNotesTwoPointFourFivePercentDueTwentyNineteenMember" xlink:label="loc_pnr_SeniorNotesTwoPointFourFivePercentDueTwentyNineteenMember_BE74C679A927B2DADCF9DBCD932B4255" xlink:type="locator"/>
<link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_F9F421A6ADC06EC17633DBCD932B2D80" xlink:to="loc_pnr_SeniorNotesTwoPointFourFivePercentDueTwentyNineteenMember_BE74C679A927B2DADCF9DBCD932B4255" xlink:type="arc"/>
<link:loc xlink:href="pnr-20180331.xsd#pnr_SeniorNotesThreePointSixTwoFivePercentDueTwentyTwentyMember" xlink:label="loc_pnr_SeniorNotesThreePointSixTwoFivePercentDueTwentyTwentyMember_03C079830298F274B744DBCD932BAD58" xlink:type="locator"/>
<link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_F9F421A6ADC06EC17633DBCD932B2D80" xlink:to="loc_pnr_SeniorNotesThreePointSixTwoFivePercentDueTwentyTwentyMember_03C079830298F274B744DBCD932BAD58" xlink:type="arc"/>
<link:loc xlink:href="pnr-20180331.xsd#pnr_SeniorNotesFivePointZeroZeroZeroPercentDueTwentyTwentyOneMember" xlink:label="loc_pnr_SeniorNotesFivePointZeroZeroZeroPercentDueTwentyTwentyOneMember_37BACDC4AEDCA2DD46F0DBCD932BBB14" xlink:type="locator"/>
<link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_F9F421A6ADC06EC17633DBCD932B2D80" xlink:to="loc_pnr_SeniorNotesFivePointZeroZeroZeroPercentDueTwentyTwentyOneMember_37BACDC4AEDCA2DD46F0DBCD932BBB14" xlink:type="arc"/>
<link:loc xlink:href="pnr-20180331.xsd#pnr_SeniorNotesThreePointOneFiveZeroPercentDueTwentyTwentyTwoMember" xlink:label="loc_pnr_SeniorNotesThreePointOneFiveZeroPercentDueTwentyTwentyTwoMember_D99FFD3C313376BD5C06DBCD932B1AE9" xlink:type="locator"/>
<link:definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_F9F421A6ADC06EC17633DBCD932B2D80" xlink:to="loc_pnr_SeniorNotesThreePointOneFiveZeroPercentDueTwentyTwentyTwoMember_D99FFD3C313376BD5C06DBCD932B1AE9" xlink:type="arc"/>
<link:loc xlink:href="pnr-20180331.xsd#pnr_SeniorNotesFourPointSixFivePercentDueTwentyTwentyFiveMember" xlink:label="loc_pnr_SeniorNotesFourPointSixFivePercentDueTwentyTwentyFiveMember_810863C78E85187268A0DBCD932B9B30" xlink:type="locator"/>
<link:definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_F9F421A6ADC06EC17633DBCD932B2D80" xlink:to="loc_pnr_SeniorNotesFourPointSixFivePercentDueTwentyTwentyFiveMember_810863C78E85187268A0DBCD932B9B30" xlink:type="arc"/>
<link:loc xlink:href="pnr-20180331.xsd#pnr_SeniorNotesThreePointNineFivePercentDueTwentyTwentyThreeMember" xlink:label="loc_pnr_SeniorNotesThreePointNineFivePercentDueTwentyTwentyThreeMember_A432BF74E1F853C4BFC1DBCD932BFA01" xlink:type="locator"/>
<link:definitionArc order="9" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_F9F421A6ADC06EC17633DBCD932B2D80" xlink:to="loc_pnr_SeniorNotesThreePointNineFivePercentDueTwentyTwentyThreeMember_A432BF74E1F853C4BFC1DBCD932BFA01" xlink:type="arc"/>
<link:loc xlink:href="pnr-20180331.xsd#pnr_SeniorNotesFourPointFiveFivePercentDueTwentyTwentyEightMember" xlink:label="loc_pnr_SeniorNotesFourPointFiveFivePercentDueTwentyTwentyEightMember_7553CE19DDBE004E47CDDBCD932B49EA" xlink:type="locator"/>
<link:definitionArc order="10" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_F9F421A6ADC06EC17633DBCD932B2D80" xlink:to="loc_pnr_SeniorNotesFourPointFiveFivePercentDueTwentyTwentyEightMember_7553CE19DDBE004E47CDDBCD932B49EA" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_OtherDebtSecuritiesMember" xlink:label="loc_us-gaap_OtherDebtSecuritiesMember_B3AE6CCD6EB6B56C934CDBCD932BC5D9" xlink:type="locator"/>
<link:definitionArc order="11" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_F9F421A6ADC06EC17633DBCD932B2D80" xlink:to="loc_us-gaap_OtherDebtSecuritiesMember_B3AE6CCD6EB6B56C934CDBCD932BC5D9" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_LongtermDebtTypeAxis" xlink:label="loc_us-gaap_LongtermDebtTypeAxis_2445EDF5253CE99E6E37DBCD932C5482" xlink:type="locator"/>
<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_DC0A09BC6EB4111C588FDBCD932537D1" xlink:to="loc_us-gaap_LongtermDebtTypeAxis_2445EDF5253CE99E6E37DBCD932C5482" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_LongtermDebtTypeDomain" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_2B7336DE91449E3E8C89DBCD932CA9B5_default" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_2445EDF5253CE99E6E37DBCD932C5482" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_2B7336DE91449E3E8C89DBCD932CA9B5_default" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_LongtermDebtTypeDomain" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_2B7336DE91449E3E8C89DBCD932CA9B5" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_2445EDF5253CE99E6E37DBCD932C5482" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_2B7336DE91449E3E8C89DBCD932CA9B5" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_CommercialPaperMember" xlink:label="loc_us-gaap_CommercialPaperMember_6CD426B1DC04D790FAE0DBCD932CC906" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_2B7336DE91449E3E8C89DBCD932CA9B5" xlink:to="loc_us-gaap_CommercialPaperMember_6CD426B1DC04D790FAE0DBCD932CC906" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_SeniorNotesMember" xlink:label="loc_us-gaap_SeniorNotesMember_4A8FD9BE41C94B3D4A1EDBCD932C3C6A" xlink:type="locator"/>
<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_2B7336DE91449E3E8C89DBCD932CA9B5" xlink:to="loc_us-gaap_SeniorNotesMember_4A8FD9BE41C94B3D4A1EDBCD932C3C6A" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_OtherDebtSecuritiesMember" xlink:label="loc_us-gaap_OtherDebtSecuritiesMember_6B1701A73428B29E3CD0DBCD932CEAFB" xlink:type="locator"/>
<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_2B7336DE91449E3E8C89DBCD932CA9B5" xlink:to="loc_us-gaap_OtherDebtSecuritiesMember_6B1701A73428B29E3CD0DBCD932CEAFB" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_RangeAxis" xlink:label="loc_us-gaap_RangeAxis_5CF24382BA9CABDEC34FDBCD932C96CD" xlink:type="locator"/>
<link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_DC0A09BC6EB4111C588FDBCD932537D1" xlink:to="loc_us-gaap_RangeAxis_5CF24382BA9CABDEC34FDBCD932C96CD" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_RangeMember" xlink:label="loc_us-gaap_RangeMember_3F381D510173D660F41DDBCD932C7279_default" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RangeAxis_5CF24382BA9CABDEC34FDBCD932C96CD" xlink:to="loc_us-gaap_RangeMember_3F381D510173D660F41DDBCD932C7279_default" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_RangeMember" xlink:label="loc_us-gaap_RangeMember_3F381D510173D660F41DDBCD932C7279" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RangeAxis_5CF24382BA9CABDEC34FDBCD932C96CD" xlink:to="loc_us-gaap_RangeMember_3F381D510173D660F41DDBCD932C7279" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_MinimumMember" xlink:label="loc_us-gaap_MinimumMember_F8ED17B7976C0691B512DBCD932C07CF" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RangeMember_3F381D510173D660F41DDBCD932C7279" xlink:to="loc_us-gaap_MinimumMember_F8ED17B7976C0691B512DBCD932C07CF" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_MaximumMember" xlink:label="loc_us-gaap_MaximumMember_B97B9BFC7409C295B10EDBCD932CB527" xlink:type="locator"/>
<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RangeMember_3F381D510173D660F41DDBCD932C7279" xlink:to="loc_us-gaap_MaximumMember_B97B9BFC7409C295B10EDBCD932CB527" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DebtWeightedAverageInterestRate" xlink:label="loc_us-gaap_DebtWeightedAverageInterestRate_538C597D1FC30433D4C2DBCD932C9F05" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_034CCFD6B13A8D5336CEDBCD932CA425" xlink:to="loc_us-gaap_DebtWeightedAverageInterestRate_538C597D1FC30433D4C2DBCD932C9F05" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_CommercialPaper" xlink:label="loc_us-gaap_CommercialPaper_67E257D64AA5F5AD4C3EDBCD932C1D26" xlink:type="locator"/>
<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_034CCFD6B13A8D5336CEDBCD932CA425" xlink:to="loc_us-gaap_CommercialPaper_67E257D64AA5F5AD4C3EDBCD932C1D26" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_UnamortizedDebtIssuanceExpense" xlink:label="loc_us-gaap_UnamortizedDebtIssuanceExpense_9571DDA0611528C7A577DBCD932C635E" xlink:type="locator"/>
<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_034CCFD6B13A8D5336CEDBCD932CA425" xlink:to="loc_us-gaap_UnamortizedDebtIssuanceExpense_9571DDA0611528C7A577DBCD932C635E" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DebtLongtermAndShorttermCombinedAmount" xlink:label="loc_us-gaap_DebtLongtermAndShorttermCombinedAmount_FB751F48D460D3649383DBCD932C4229" xlink:type="locator"/>
<link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_034CCFD6B13A8D5336CEDBCD932CA425" xlink:to="loc_us-gaap_DebtLongtermAndShorttermCombinedAmount_FB751F48D460D3649383DBCD932C4229" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DebtCurrent" xlink:label="loc_us-gaap_DebtCurrent_D7388294A250B31C9699DBCD932C60C7" xlink:type="locator"/>
<link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_034CCFD6B13A8D5336CEDBCD932CA425" xlink:to="loc_us-gaap_DebtCurrent_D7388294A250B31C9699DBCD932C60C7" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_LongTermDebtNoncurrent" xlink:label="loc_us-gaap_LongTermDebtNoncurrent_C9B6880EE5592FFA92DBDBCD932CF1D0" xlink:type="locator"/>
<link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_034CCFD6B13A8D5336CEDBCD932CA425" xlink:to="loc_us-gaap_LongTermDebtNoncurrent_C9B6880EE5592FFA92DBDBCD932CF1D0" xlink:type="arc"/>
</link:definitionLink>
<link:definitionLink xlink:role="http://www.pentair.com/role/DebtDebtOutstandingMaturesOnCalendarYearBasisDetail" xlink:type="extended">
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DebtInstrumentLineItems" xlink:label="loc_us-gaap_DebtInstrumentLineItems_C8DBE67C7916AC988614DBCD92F8B1FB" xlink:type="locator"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DebtInstrumentTable" xlink:label="loc_us-gaap_DebtInstrumentTable_712DED55136D147D8B88DBCD92F8830A" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DebtInstrumentLineItems_C8DBE67C7916AC988614DBCD92F8B1FB" xlink:to="loc_us-gaap_DebtInstrumentTable_712DED55136D147D8B88DBCD92F8830A" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DebtInstrumentAxis" xlink:label="loc_us-gaap_DebtInstrumentAxis_BEFA9528CA5A9F6A6CA7DBCD92F887B4" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_712DED55136D147D8B88DBCD92F8830A" xlink:to="loc_us-gaap_DebtInstrumentAxis_BEFA9528CA5A9F6A6CA7DBCD92F887B4" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DebtInstrumentNameDomain" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_8E337DF9A1CC62A94D66DBCD92F89DFA_default" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DebtInstrumentAxis_BEFA9528CA5A9F6A6CA7DBCD92F887B4" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_8E337DF9A1CC62A94D66DBCD92F89DFA_default" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DebtInstrumentNameDomain" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_8E337DF9A1CC62A94D66DBCD92F89DFA" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DebtInstrumentAxis_BEFA9528CA5A9F6A6CA7DBCD92F887B4" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_8E337DF9A1CC62A94D66DBCD92F89DFA" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_LongtermDebtTypeAxis" xlink:label="loc_us-gaap_LongtermDebtTypeAxis_F1DD800B670EB65998F9DBCD92F88FDE" xlink:type="locator"/>
<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_712DED55136D147D8B88DBCD92F8830A" xlink:to="loc_us-gaap_LongtermDebtTypeAxis_F1DD800B670EB65998F9DBCD92F88FDE" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_LongtermDebtTypeDomain" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_FB9F5EE55FA152E0164FDBCD92F8758F_default" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_F1DD800B670EB65998F9DBCD92F88FDE" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_FB9F5EE55FA152E0164FDBCD92F8758F_default" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_LongtermDebtTypeDomain" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_FB9F5EE55FA152E0164FDBCD92F8758F" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_F1DD800B670EB65998F9DBCD92F88FDE" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_FB9F5EE55FA152E0164FDBCD92F8758F" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_SeniorNotesMember" xlink:label="loc_us-gaap_SeniorNotesMember_600DAA114B4A7000C466DBCD92F83B85" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_FB9F5EE55FA152E0164FDBCD92F8758F" xlink:to="loc_us-gaap_SeniorNotesMember_600DAA114B4A7000C466DBCD92F83B85" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_OtherDebtSecuritiesMember" xlink:label="loc_us-gaap_OtherDebtSecuritiesMember_2B6486E5F1242506E102DBCD92F8CAC7" xlink:type="locator"/>
<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_FB9F5EE55FA152E0164FDBCD92F8758F" xlink:to="loc_us-gaap_OtherDebtSecuritiesMember_2B6486E5F1242506E102DBCD92F8CAC7" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalRemainderOfFiscalYear" xlink:label="loc_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalRemainderOfFiscalYear_3BA46853E5323B9462CADBCD92F82602" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_C8DBE67C7916AC988614DBCD92F8B1FB" xlink:to="loc_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalRemainderOfFiscalYear_3BA46853E5323B9462CADBCD92F82602" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInNextTwelveMonths" xlink:label="loc_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInNextTwelveMonths_B1FEBDEF3F1D3770F668DBCD92F8C41A" xlink:type="locator"/>
<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_C8DBE67C7916AC988614DBCD92F8B1FB" xlink:to="loc_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInNextTwelveMonths_B1FEBDEF3F1D3770F668DBCD92F8C41A" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearTwo" xlink:label="loc_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearTwo_860FEE2DC43152D2AA4ADBCD92F896BE" xlink:type="locator"/>
<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_C8DBE67C7916AC988614DBCD92F8B1FB" xlink:to="loc_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearTwo_860FEE2DC43152D2AA4ADBCD92F896BE" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearThree" xlink:label="loc_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearThree_31D99647EC2AD1DF58B6DBCD92F814A7" xlink:type="locator"/>
<link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_C8DBE67C7916AC988614DBCD92F8B1FB" xlink:to="loc_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearThree_31D99647EC2AD1DF58B6DBCD92F814A7" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFour" xlink:label="loc_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFour_24B3A7C416E05CA6ED85DBCD92F9DA7D" xlink:type="locator"/>
<link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_C8DBE67C7916AC988614DBCD92F8B1FB" xlink:to="loc_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFour_24B3A7C416E05CA6ED85DBCD92F9DA7D" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFive" xlink:label="loc_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFive_BDCA10A55CD6EEA34FA3DBCD92F91F4A" xlink:type="locator"/>
<link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_C8DBE67C7916AC988614DBCD92F8B1FB" xlink:to="loc_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFive_BDCA10A55CD6EEA34FA3DBCD92F91F4A" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalAfterYearFive" xlink:label="loc_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalAfterYearFive_1DB88632036D83873A7BDBCD92F94217" xlink:type="locator"/>
<link:definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_C8DBE67C7916AC988614DBCD92F8B1FB" xlink:to="loc_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalAfterYearFive_1DB88632036D83873A7BDBCD92F94217" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_LongTermDebt" xlink:label="loc_us-gaap_LongTermDebt_C53B2DB7910F069F67F7DBCD92F99098" xlink:type="locator"/>
<link:definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_C8DBE67C7916AC988614DBCD92F8B1FB" xlink:to="loc_us-gaap_LongTermDebt_C53B2DB7910F069F67F7DBCD92F99098" xlink:type="arc"/>
</link:definitionLink>
<link:definitionLink xlink:role="http://www.pentair.com/role/DebtTables" xlink:type="extended"/>
<link:definitionLink xlink:role="http://www.pentair.com/role/DerivativesAndFinancialInstruments" xlink:type="extended"/>
<link:definitionLink xlink:role="http://www.pentair.com/role/DerivativesAndFinancialInstrumentsAdditionalInformationDetail" xlink:type="extended">
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DerivativeLineItems" xlink:label="loc_us-gaap_DerivativeLineItems_D0941BF8B0DB367291D8E33D7FBB1835" xlink:type="locator"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DerivativeTable" xlink:label="loc_us-gaap_DerivativeTable_D9D688D86B0264D44B17E33D7FBB20DF" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DerivativeLineItems_D0941BF8B0DB367291D8E33D7FBB1835" xlink:to="loc_us-gaap_DerivativeTable_D9D688D86B0264D44B17E33D7FBB20DF" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DebtInstrumentAxis" xlink:label="loc_us-gaap_DebtInstrumentAxis_C4E9CB3D246104F4375EE33D7FBB103D" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeTable_D9D688D86B0264D44B17E33D7FBB20DF" xlink:to="loc_us-gaap_DebtInstrumentAxis_C4E9CB3D246104F4375EE33D7FBB103D" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DebtInstrumentNameDomain" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_FF98D186579D6D4D0C95E33D7FBB5C3F_default" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DebtInstrumentAxis_C4E9CB3D246104F4375EE33D7FBB103D" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_FF98D186579D6D4D0C95E33D7FBB5C3F_default" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DebtInstrumentNameDomain" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_FF98D186579D6D4D0C95E33D7FBB5C3F" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DebtInstrumentAxis_C4E9CB3D246104F4375EE33D7FBB103D" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_FF98D186579D6D4D0C95E33D7FBB5C3F" xlink:type="arc"/>
<link:loc xlink:href="pnr-20180331.xsd#pnr_SeniorNotesTwoPointFourFivePercentDueTwentyNineteenMember" xlink:label="loc_pnr_SeniorNotesTwoPointFourFivePercentDueTwentyNineteenMember_18868C2D909D19D563C6E33D7FBB3747" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_FF98D186579D6D4D0C95E33D7FBB5C3F" xlink:to="loc_pnr_SeniorNotesTwoPointFourFivePercentDueTwentyNineteenMember_18868C2D909D19D563C6E33D7FBB3747" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_LongtermDebtTypeAxis" xlink:label="loc_us-gaap_LongtermDebtTypeAxis_6B7A1B0D029B89CC6232E33D7FBB037F" xlink:type="locator"/>
<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeTable_D9D688D86B0264D44B17E33D7FBB20DF" xlink:to="loc_us-gaap_LongtermDebtTypeAxis_6B7A1B0D029B89CC6232E33D7FBB037F" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_LongtermDebtTypeDomain" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_BB59C89E86456CC19B8BE33D7FBBEFD4_default" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_6B7A1B0D029B89CC6232E33D7FBB037F" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_BB59C89E86456CC19B8BE33D7FBBEFD4_default" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_LongtermDebtTypeDomain" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_BB59C89E86456CC19B8BE33D7FBBEFD4" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_6B7A1B0D029B89CC6232E33D7FBB037F" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_BB59C89E86456CC19B8BE33D7FBBEFD4" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_SeniorNotesMember" xlink:label="loc_us-gaap_SeniorNotesMember_84EEA32559A6BFEBC230E33D7FBB60C7" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_BB59C89E86456CC19B8BE33D7FBBEFD4" xlink:to="loc_us-gaap_SeniorNotesMember_84EEA32559A6BFEBC230E33D7FBB60C7" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DerivativeInstrumentRiskAxis" xlink:label="loc_us-gaap_DerivativeInstrumentRiskAxis_CAFED81BA2BA1EA412DEE33D7FBBB7C0" xlink:type="locator"/>
<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeTable_D9D688D86B0264D44B17E33D7FBB20DF" xlink:to="loc_us-gaap_DerivativeInstrumentRiskAxis_CAFED81BA2BA1EA412DEE33D7FBBB7C0" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DerivativeContractTypeDomain" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_4CFD661B5EEC93EAA09DE33D7FBBF407_default" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_CAFED81BA2BA1EA412DEE33D7FBBB7C0" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_4CFD661B5EEC93EAA09DE33D7FBBF407_default" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DerivativeContractTypeDomain" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_4CFD661B5EEC93EAA09DE33D7FBBF407" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_CAFED81BA2BA1EA412DEE33D7FBBB7C0" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_4CFD661B5EEC93EAA09DE33D7FBBF407" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ForeignExchangeContractMember" xlink:label="loc_us-gaap_ForeignExchangeContractMember_ED81FD2A373BAEC0A16CE33D7FBB3BAF" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_4CFD661B5EEC93EAA09DE33D7FBBF407" xlink:to="loc_us-gaap_ForeignExchangeContractMember_ED81FD2A373BAEC0A16CE33D7FBB3BAF" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.sec.gov/invest/2013/invest-2013-01-31.xsd#invest_DerivativeNotionalAmount" xlink:label="loc_invest_DerivativeNotionalAmount_57ABC6828AD03C4BB2A3E33D7FBB2F3B" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeLineItems_D0941BF8B0DB367291D8E33D7FBB1835" xlink:to="loc_invest_DerivativeNotionalAmount_57ABC6828AD03C4BB2A3E33D7FBB2F3B" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DerivativeAmountOfHedgedItem" xlink:label="loc_us-gaap_DerivativeAmountOfHedgedItem_96AAA7FBCD18B5F63180E33D7FBBCA52" xlink:type="locator"/>
<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeLineItems_D0941BF8B0DB367291D8E33D7FBB1835" xlink:to="loc_us-gaap_DerivativeAmountOfHedgedItem_96AAA7FBCD18B5F63180E33D7FBBCA52" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DebtInstrumentInterestRateStatedPercentage" xlink:label="loc_us-gaap_DebtInstrumentInterestRateStatedPercentage_04A8AB684646BAF88F3EE33D7FBB3BC4" xlink:type="locator"/>
<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeLineItems_D0941BF8B0DB367291D8E33D7FBB1835" xlink:to="loc_us-gaap_DebtInstrumentInterestRateStatedPercentage_04A8AB684646BAF88F3EE33D7FBB3BC4" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_TranslationAdjustmentForNetInvestmentHedgeIncreaseDecreaseNetOfTax" xlink:label="loc_us-gaap_TranslationAdjustmentForNetInvestmentHedgeIncreaseDecreaseNetOfTax_378E963C8CC879B7B40FE33D7FBB1254" xlink:type="locator"/>
<link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeLineItems_D0941BF8B0DB367291D8E33D7FBB1835" xlink:to="loc_us-gaap_TranslationAdjustmentForNetInvestmentHedgeIncreaseDecreaseNetOfTax_378E963C8CC879B7B40FE33D7FBB1254" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ImpairedAssetsToBeDisposedOfByMethodOtherThanSaleCarryingValueOfAsset" xlink:label="loc_us-gaap_ImpairedAssetsToBeDisposedOfByMethodOtherThanSaleCarryingValueOfAsset_43D1B130AD653BC6AB1EE33D7FBB212B" xlink:type="locator"/>
<link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeLineItems_D0941BF8B0DB367291D8E33D7FBB1835" xlink:to="loc_us-gaap_ImpairedAssetsToBeDisposedOfByMethodOtherThanSaleCarryingValueOfAsset_43D1B130AD653BC6AB1EE33D7FBB212B" xlink:type="arc"/>
</link:definitionLink>
<link:definitionLink xlink:role="http://www.pentair.com/role/DerivativesAndFinancialInstrumentsAssetsAndLiabilitiesMeasuredAtFairValueDetail" xlink:type="extended">
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems" xlink:label="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_5D0F7999F32FC8F9BDBFCFF41274CB47" xlink:type="locator"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable" xlink:label="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_994D669074AB333B6431CFF41273FD5D" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_5D0F7999F32FC8F9BDBFCFF41274CB47" xlink:to="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_994D669074AB333B6431CFF41273FD5D" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_FairValueByFairValueHierarchyLevelAxis" xlink:label="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_F8E4677932832F92F255CFF412731002" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_994D669074AB333B6431CFF41273FD5D" xlink:to="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_F8E4677932832F92F255CFF412731002" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_03285B199EFCBB9E3A8CCFF41273E918_default" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_F8E4677932832F92F255CFF412731002" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_03285B199EFCBB9E3A8CCFF41273E918_default" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_03285B199EFCBB9E3A8CCFF41273E918" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_F8E4677932832F92F255CFF412731002" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_03285B199EFCBB9E3A8CCFF41273E918" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_FairValueInputsLevel1Member" xlink:label="loc_us-gaap_FairValueInputsLevel1Member_3E3ED67386BA7203BE93CFF41273AB42" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_03285B199EFCBB9E3A8CCFF41273E918" xlink:to="loc_us-gaap_FairValueInputsLevel1Member_3E3ED67386BA7203BE93CFF41273AB42" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_FairValueInputsLevel2Member" xlink:label="loc_us-gaap_FairValueInputsLevel2Member_B54312BB43850EABF1DDCFF41274DB88" xlink:type="locator"/>
<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_03285B199EFCBB9E3A8CCFF41273E918" xlink:to="loc_us-gaap_FairValueInputsLevel2Member_B54312BB43850EABF1DDCFF41274DB88" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_FairValueInputsLevel3Member" xlink:label="loc_us-gaap_FairValueInputsLevel3Member_17CB09199DA3BA5562B5CFF412740E2D" xlink:type="locator"/>
<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_03285B199EFCBB9E3A8CCFF41273E918" xlink:to="loc_us-gaap_FairValueInputsLevel3Member_17CB09199DA3BA5562B5CFF412740E2D" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_FairValueByMeasurementFrequencyAxis" xlink:label="loc_us-gaap_FairValueByMeasurementFrequencyAxis_B384C2326F16371EE65DCFF41274C4E1" xlink:type="locator"/>
<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_994D669074AB333B6431CFF41273FD5D" xlink:to="loc_us-gaap_FairValueByMeasurementFrequencyAxis_B384C2326F16371EE65DCFF41274C4E1" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_FairValueMeasurementFrequencyDomain" xlink:label="loc_us-gaap_FairValueMeasurementFrequencyDomain_84B37E5161A831046238CFF41274F150_default" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByMeasurementFrequencyAxis_B384C2326F16371EE65DCFF41274C4E1" xlink:to="loc_us-gaap_FairValueMeasurementFrequencyDomain_84B37E5161A831046238CFF41274F150_default" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_FairValueMeasurementFrequencyDomain" xlink:label="loc_us-gaap_FairValueMeasurementFrequencyDomain_84B37E5161A831046238CFF41274F150" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByMeasurementFrequencyAxis_B384C2326F16371EE65DCFF41274C4E1" xlink:to="loc_us-gaap_FairValueMeasurementFrequencyDomain_84B37E5161A831046238CFF41274F150" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_FairValueMeasurementsRecurringMember" xlink:label="loc_us-gaap_FairValueMeasurementsRecurringMember_E5F117DC8B0D49BDA494CFF41274C556" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementFrequencyDomain_84B37E5161A831046238CFF41274F150" xlink:to="loc_us-gaap_FairValueMeasurementsRecurringMember_E5F117DC8B0D49BDA494CFF41274C556" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ImpairmentOfIntangibleAssetsExcludingGoodwill" xlink:label="loc_us-gaap_ImpairmentOfIntangibleAssetsExcludingGoodwill_9CA61881CFE836F5FF29CFF41274E43A" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_5D0F7999F32FC8F9BDBFCFF41274CB47" xlink:to="loc_us-gaap_ImpairmentOfIntangibleAssetsExcludingGoodwill_9CA61881CFE836F5FF29CFF41274E43A" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ForeignCurrencyContractAssetFairValueDisclosure" xlink:label="loc_us-gaap_ForeignCurrencyContractAssetFairValueDisclosure_35725880695F0D80CA49CFF41274C2A6" xlink:type="locator"/>
<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_5D0F7999F32FC8F9BDBFCFF41274CB47" xlink:to="loc_us-gaap_ForeignCurrencyContractAssetFairValueDisclosure_35725880695F0D80CA49CFF41274C2A6" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ForeignCurrencyContractsLiabilityFairValueDisclosure" xlink:label="loc_us-gaap_ForeignCurrencyContractsLiabilityFairValueDisclosure_F356CB35DBBE47281CA6CFF41274DCAE" xlink:type="locator"/>
<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_5D0F7999F32FC8F9BDBFCFF41274CB47" xlink:to="loc_us-gaap_ForeignCurrencyContractsLiabilityFairValueDisclosure_F356CB35DBBE47281CA6CFF41274DCAE" xlink:type="arc"/>
<link:loc xlink:href="pnr-20180331.xsd#pnr_DeferredCompensationPlanAssetsFairValueDisclosure" xlink:label="loc_pnr_DeferredCompensationPlanAssetsFairValueDisclosure_9EA864594F9AA0E84FF2CFF41274B308" xlink:type="locator"/>
<link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_5D0F7999F32FC8F9BDBFCFF41274CB47" xlink:to="loc_pnr_DeferredCompensationPlanAssetsFairValueDisclosure_9EA864594F9AA0E84FF2CFF41274B308" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DerivativeAssetsLiabilitiesAtFairValueNet" xlink:label="loc_us-gaap_DerivativeAssetsLiabilitiesAtFairValueNet_B8411B16A2971A630881CFF412745356" xlink:type="locator"/>
<link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_5D0F7999F32FC8F9BDBFCFF41274CB47" xlink:to="loc_us-gaap_DerivativeAssetsLiabilitiesAtFairValueNet_B8411B16A2971A630881CFF412745356" xlink:type="arc"/>
</link:definitionLink>
<link:definitionLink xlink:role="http://www.pentair.com/role/DerivativesAndFinancialInstrumentsRecordedAmountsAndEstimatedFairValuesOfLongTermDebtAndDerivativeFinancialInstrumentsDetail" xlink:type="extended">
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DerivativeLineItems" xlink:label="loc_us-gaap_DerivativeLineItems_C2FB5E1FA60D5FA4EDE0CFF4127DE78D" xlink:type="locator"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DerivativeTable" xlink:label="loc_us-gaap_DerivativeTable_641CB743998E6BB9C6EDCFF4127D245F" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DerivativeLineItems_C2FB5E1FA60D5FA4EDE0CFF4127DE78D" xlink:to="loc_us-gaap_DerivativeTable_641CB743998E6BB9C6EDCFF4127D245F" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_FairValueByMeasurementBasisAxis" xlink:label="loc_us-gaap_FairValueByMeasurementBasisAxis_86A6F973AAAF6E11E3B6CFF4127D81C3" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeTable_641CB743998E6BB9C6EDCFF4127D245F" xlink:to="loc_us-gaap_FairValueByMeasurementBasisAxis_86A6F973AAAF6E11E3B6CFF4127D81C3" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_PortionAtFairValueFairValueDisclosureMember" xlink:label="loc_us-gaap_PortionAtFairValueFairValueDisclosureMember_0249CA5ACDB5F0CB347ECFF4127DB2B8_default" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByMeasurementBasisAxis_86A6F973AAAF6E11E3B6CFF4127D81C3" xlink:to="loc_us-gaap_PortionAtFairValueFairValueDisclosureMember_0249CA5ACDB5F0CB347ECFF4127DB2B8_default" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_FairValueDisclosureItemAmountsDomain" xlink:label="loc_us-gaap_FairValueDisclosureItemAmountsDomain_5CEB1265C52575226A1CCFF4127DBCCC" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByMeasurementBasisAxis_86A6F973AAAF6E11E3B6CFF4127D81C3" xlink:to="loc_us-gaap_FairValueDisclosureItemAmountsDomain_5CEB1265C52575226A1CCFF4127DBCCC" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_PortionAtFairValueFairValueDisclosureMember" xlink:label="loc_us-gaap_PortionAtFairValueFairValueDisclosureMember_0249CA5ACDB5F0CB347ECFF4127DB2B8" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueDisclosureItemAmountsDomain_5CEB1265C52575226A1CCFF4127DBCCC" xlink:to="loc_us-gaap_PortionAtFairValueFairValueDisclosureMember_0249CA5ACDB5F0CB347ECFF4127DB2B8" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_CarryingReportedAmountFairValueDisclosureMember" xlink:label="loc_us-gaap_CarryingReportedAmountFairValueDisclosureMember_E4ADE8E0DBEA573F51DECFF4127DB9F7" xlink:type="locator"/>
<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueDisclosureItemAmountsDomain_5CEB1265C52575226A1CCFF4127DBCCC" xlink:to="loc_us-gaap_CarryingReportedAmountFairValueDisclosureMember_E4ADE8E0DBEA573F51DECFF4127DB9F7" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_EstimateOfFairValueFairValueDisclosureMember" xlink:label="loc_us-gaap_EstimateOfFairValueFairValueDisclosureMember_7BDB1D83BA1E75EDAFD3CFF4127D870F" xlink:type="locator"/>
<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueDisclosureItemAmountsDomain_5CEB1265C52575226A1CCFF4127DBCCC" xlink:to="loc_us-gaap_EstimateOfFairValueFairValueDisclosureMember_7BDB1D83BA1E75EDAFD3CFF4127D870F" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_LongtermDebtPercentageBearingVariableInterestAmount" xlink:label="loc_us-gaap_LongtermDebtPercentageBearingVariableInterestAmount_A8234956BD02DD1FC613CFF4127DB886" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeLineItems_C2FB5E1FA60D5FA4EDE0CFF4127DE78D" xlink:to="loc_us-gaap_LongtermDebtPercentageBearingVariableInterestAmount_A8234956BD02DD1FC613CFF4127DB886" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_LongtermDebtPercentageBearingFixedInterestAmount" xlink:label="loc_us-gaap_LongtermDebtPercentageBearingFixedInterestAmount_50A950F9A59689DA07D5CFF4127D4971" xlink:type="locator"/>
<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeLineItems_C2FB5E1FA60D5FA4EDE0CFF4127DE78D" xlink:to="loc_us-gaap_LongtermDebtPercentageBearingFixedInterestAmount_50A950F9A59689DA07D5CFF4127D4971" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_LongTermDebt" xlink:label="loc_us-gaap_LongTermDebt_70FA5533386300B55092CFF4127D4705" xlink:type="locator"/>
<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeLineItems_C2FB5E1FA60D5FA4EDE0CFF4127DE78D" xlink:to="loc_us-gaap_LongTermDebt_70FA5533386300B55092CFF4127D4705" xlink:type="arc"/>
</link:definitionLink>
<link:definitionLink xlink:role="http://www.pentair.com/role/DerivativesAndFinancialInstrumentsTables" xlink:type="extended"/>
<link:definitionLink xlink:role="http://www.pentair.com/role/DiscontinuedOperations" xlink:type="extended"/>
<link:definitionLink xlink:role="http://www.pentair.com/role/DiscontinuedOperationsAdditionalInformationDetails" xlink:type="extended">
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsLineItems" xlink:label="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsLineItems_13D9722C4542FDBD5278D43B46787888" xlink:type="locator"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsTable" xlink:label="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsTable_15287D0B0A4B6E1516C7D43B467853EC" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsLineItems_13D9722C4542FDBD5278D43B46787888" xlink:to="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsTable_15287D0B0A4B6E1516C7D43B467853EC" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_StatementOperatingActivitiesSegmentAxis" xlink:label="loc_us-gaap_StatementOperatingActivitiesSegmentAxis_6B6462C512E4243E6991D43B46789F9E" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsTable_15287D0B0A4B6E1516C7D43B467853EC" xlink:to="loc_us-gaap_StatementOperatingActivitiesSegmentAxis_6B6462C512E4243E6991D43B46789F9E" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_SegmentOperatingActivitiesDomain" xlink:label="loc_us-gaap_SegmentOperatingActivitiesDomain_FC3896094B4BA64C913BD43B46785515_default" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementOperatingActivitiesSegmentAxis_6B6462C512E4243E6991D43B46789F9E" xlink:to="loc_us-gaap_SegmentOperatingActivitiesDomain_FC3896094B4BA64C913BD43B46785515_default" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_SegmentOperatingActivitiesDomain" xlink:label="loc_us-gaap_SegmentOperatingActivitiesDomain_FC3896094B4BA64C913BD43B46785515" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementOperatingActivitiesSegmentAxis_6B6462C512E4243E6991D43B46789F9E" xlink:to="loc_us-gaap_SegmentOperatingActivitiesDomain_FC3896094B4BA64C913BD43B46785515" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DiscontinuedOperationsDisposedOfBySaleMember" xlink:label="loc_us-gaap_DiscontinuedOperationsDisposedOfBySaleMember_284F6DE60F294B1A4B98D43B46789359" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentOperatingActivitiesDomain_FC3896094B4BA64C913BD43B46785515" xlink:to="loc_us-gaap_DiscontinuedOperationsDisposedOfBySaleMember_284F6DE60F294B1A4B98D43B46789359" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_SegmentDiscontinuedOperationsMember" xlink:label="loc_us-gaap_SegmentDiscontinuedOperationsMember_4B88581B7B8C521A49DFD43B4678CBE0" xlink:type="locator"/>
<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentOperatingActivitiesDomain_FC3896094B4BA64C913BD43B46785515" xlink:to="loc_us-gaap_SegmentDiscontinuedOperationsMember_4B88581B7B8C521A49DFD43B4678CBE0" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ProceedsFromDivestitureOfBusinesses" xlink:label="loc_us-gaap_ProceedsFromDivestitureOfBusinesses_78F1C1B254AE96487112D43B4678A24F" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsLineItems_13D9722C4542FDBD5278D43B46787888" xlink:to="loc_us-gaap_ProceedsFromDivestitureOfBusinesses_78F1C1B254AE96487112D43B4678A24F" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DiscontinuedOperationProvisionForLossGainOnDisposalNetOfTax" xlink:label="loc_us-gaap_DiscontinuedOperationProvisionForLossGainOnDisposalNetOfTax_067870A8E44FFE415DD8D43B4678C88D" xlink:type="locator"/>
<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsLineItems_13D9722C4542FDBD5278D43B46787888" xlink:to="loc_us-gaap_DiscontinuedOperationProvisionForLossGainOnDisposalNetOfTax_067870A8E44FFE415DD8D43B4678C88D" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_BusinessExitCosts1" xlink:label="loc_us-gaap_BusinessExitCosts1_563E6C9CE52F5A3A4054D43B46789A82" xlink:type="locator"/>
<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsLineItems_13D9722C4542FDBD5278D43B46787888" xlink:to="loc_us-gaap_BusinessExitCosts1_563E6C9CE52F5A3A4054D43B46789A82" xlink:type="arc"/>
</link:definitionLink>
<link:definitionLink xlink:role="http://www.pentair.com/role/DiscontinuedOperationsBalanceSheetDetails" xlink:type="extended"/>
<link:definitionLink xlink:role="http://www.pentair.com/role/DiscontinuedOperationsIncomeStatementDetails" xlink:type="extended"/>
<link:definitionLink xlink:role="http://www.pentair.com/role/DiscontinuedOperationsTables" xlink:type="extended"/>
<link:definitionLink xlink:role="http://www.pentair.com/role/DocumentAndEntityInformation" xlink:type="extended">
<link:loc xlink:href="http://xbrl.sec.gov/dei/2014/dei-2014-01-31.xsd#dei_DocumentInformationLineItems" xlink:label="loc_dei_DocumentInformationLineItems_1A938CDF062454A38083C6B39FC9EEA7" xlink:type="locator"/>
<link:loc xlink:href="http://xbrl.sec.gov/dei/2014/dei-2014-01-31.xsd#dei_EntitiesTable" xlink:label="loc_dei_EntitiesTable_1D6AB222C2435212854FA72EDF683A15" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_dei_DocumentInformationLineItems_1A938CDF062454A38083C6B39FC9EEA7" xlink:to="loc_dei_EntitiesTable_1D6AB222C2435212854FA72EDF683A15" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment"/>
<link:loc xlink:href="http://xbrl.sec.gov/dei/2014/dei-2014-01-31.xsd#dei_LegalEntityAxis" xlink:label="loc_dei_LegalEntityAxis_4527266745725EA6A79D71CE66E3AEEC" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_dei_EntitiesTable_1D6AB222C2435212854FA72EDF683A15" xlink:to="loc_dei_LegalEntityAxis_4527266745725EA6A79D71CE66E3AEEC" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.sec.gov/dei/2014/dei-2014-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_42C91CBEF552CB4DC5EE57C1CDE556EE_E3B43B43A3E7574E8DA0F8529D4EC1C5" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_4527266745725EA6A79D71CE66E3AEEC" xlink:to="loc_dei_EntityDomain_42C91CBEF552CB4DC5EE57C1CDE556EE_E3B43B43A3E7574E8DA0F8529D4EC1C5" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.sec.gov/dei/2014/dei-2014-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_D1B088EBE9125383A7C0C96EE21D0B75" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_4527266745725EA6A79D71CE66E3AEEC" xlink:to="loc_dei_EntityDomain_D1B088EBE9125383A7C0C96EE21D0B75" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.sec.gov/dei/2014/dei-2014-01-31.xsd#dei_EntityRegistrantName" xlink:label="loc_dei_EntityRegistrantName_50DA678B950F53B4BB363E4F932ED626" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_1A938CDF062454A38083C6B39FC9EEA7" xlink:to="loc_dei_EntityRegistrantName_50DA678B950F53B4BB363E4F932ED626" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.sec.gov/dei/2014/dei-2014-01-31.xsd#dei_EntityCentralIndexKey" xlink:label="loc_dei_EntityCentralIndexKey_ECE336942EB0501FBD1B07655E65C513" xlink:type="locator"/>
<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_1A938CDF062454A38083C6B39FC9EEA7" xlink:to="loc_dei_EntityCentralIndexKey_ECE336942EB0501FBD1B07655E65C513" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.sec.gov/dei/2014/dei-2014-01-31.xsd#dei_CurrentFiscalYearEndDate" xlink:label="loc_dei_CurrentFiscalYearEndDate_45B287C03EE75A539DFCEC9ACE7228E5" xlink:type="locator"/>
<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_1A938CDF062454A38083C6B39FC9EEA7" xlink:to="loc_dei_CurrentFiscalYearEndDate_45B287C03EE75A539DFCEC9ACE7228E5" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.sec.gov/dei/2014/dei-2014-01-31.xsd#dei_EntityFilerCategory" xlink:label="loc_dei_EntityFilerCategory_59C128E825F9549FA47E5AB018D15150" xlink:type="locator"/>
<link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_1A938CDF062454A38083C6B39FC9EEA7" xlink:to="loc_dei_EntityFilerCategory_59C128E825F9549FA47E5AB018D15150" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.sec.gov/dei/2014/dei-2014-01-31.xsd#dei_DocumentType" xlink:label="loc_dei_DocumentType_766CCBFEC32A5901BF35D47EBDAC1A1E" xlink:type="locator"/>
<link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_1A938CDF062454A38083C6B39FC9EEA7" xlink:to="loc_dei_DocumentType_766CCBFEC32A5901BF35D47EBDAC1A1E" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.sec.gov/dei/2014/dei-2014-01-31.xsd#dei_DocumentPeriodEndDate" xlink:label="loc_dei_DocumentPeriodEndDate_E87EB8B27B99546DACA14724D9E02CA8" xlink:type="locator"/>
<link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_1A938CDF062454A38083C6B39FC9EEA7" xlink:to="loc_dei_DocumentPeriodEndDate_E87EB8B27B99546DACA14724D9E02CA8" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.sec.gov/dei/2014/dei-2014-01-31.xsd#dei_DocumentFiscalYearFocus" xlink:label="loc_dei_DocumentFiscalYearFocus_FB0A6115AAC65266ACB8A48DF06FF7E4" xlink:type="locator"/>
<link:definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_1A938CDF062454A38083C6B39FC9EEA7" xlink:to="loc_dei_DocumentFiscalYearFocus_FB0A6115AAC65266ACB8A48DF06FF7E4" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.sec.gov/dei/2014/dei-2014-01-31.xsd#dei_DocumentFiscalPeriodFocus" xlink:label="loc_dei_DocumentFiscalPeriodFocus_E41BDA37539C59CE848B6E64960AA0C9" xlink:type="locator"/>
<link:definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_1A938CDF062454A38083C6B39FC9EEA7" xlink:to="loc_dei_DocumentFiscalPeriodFocus_E41BDA37539C59CE848B6E64960AA0C9" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.sec.gov/dei/2014/dei-2014-01-31.xsd#dei_AmendmentFlag" xlink:label="loc_dei_AmendmentFlag_C54BD0E3DFE754878A42CFF16BF32BCD" xlink:type="locator"/>
<link:definitionArc order="9" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_1A938CDF062454A38083C6B39FC9EEA7" xlink:to="loc_dei_AmendmentFlag_C54BD0E3DFE754878A42CFF16BF32BCD" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.sec.gov/dei/2014/dei-2014-01-31.xsd#dei_TradingSymbol" xlink:label="loc_dei_TradingSymbol_968EF379537054D2A44411DE9AEECE32" xlink:type="locator"/>
<link:definitionArc order="10" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_1A938CDF062454A38083C6B39FC9EEA7" xlink:to="loc_dei_TradingSymbol_968EF379537054D2A44411DE9AEECE32" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.sec.gov/dei/2014/dei-2014-01-31.xsd#dei_EntityCommonStockSharesOutstanding" xlink:label="loc_dei_EntityCommonStockSharesOutstanding_15223567057E53A9AE3E58F5D26B4547" xlink:type="locator"/>
<link:definitionArc order="11" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_1A938CDF062454A38083C6B39FC9EEA7" xlink:to="loc_dei_EntityCommonStockSharesOutstanding_15223567057E53A9AE3E58F5D26B4547" xlink:type="arc"/>
</link:definitionLink>
<link:definitionLink xlink:role="http://www.pentair.com/role/EarningsPerShare" xlink:type="extended"/>
<link:definitionLink xlink:role="http://www.pentair.com/role/EarningsPerShareBasicAndDilutedEarningsPerShareDetail" xlink:type="extended"/>
<link:definitionLink xlink:role="http://www.pentair.com/role/EarningsPerShareTables" xlink:type="extended">
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_StatementLineItems" xlink:label="loc_us-gaap_StatementLineItems_81E18A24A403572D8F9F29E373233AF6" xlink:type="locator"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_StatementTable" xlink:label="loc_us-gaap_StatementTable_2ECC4D5FF77950239AF3134F27D843BF" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_81E18A24A403572D8F9F29E373233AF6" xlink:to="loc_us-gaap_StatementTable_2ECC4D5FF77950239AF3134F27D843BF" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment"/>
<link:loc xlink:href="http://xbrl.sec.gov/dei/2014/dei-2014-01-31.xsd#dei_LegalEntityAxis" xlink:label="loc_dei_LegalEntityAxis_EECCB8462B435242AF2274FBA7E90D84" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_2ECC4D5FF77950239AF3134F27D843BF" xlink:to="loc_dei_LegalEntityAxis_EECCB8462B435242AF2274FBA7E90D84" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.sec.gov/dei/2014/dei-2014-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_5A5549ADC42764CE6D9657C21CB364CA_E3B43B43A3E7574E8DA0F8529D4EC1C5" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_EECCB8462B435242AF2274FBA7E90D84" xlink:to="loc_dei_EntityDomain_5A5549ADC42764CE6D9657C21CB364CA_E3B43B43A3E7574E8DA0F8529D4EC1C5" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.sec.gov/dei/2014/dei-2014-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_55059E90ED305F498074E7AAF49D0AE6" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_EECCB8462B435242AF2274FBA7E90D84" xlink:to="loc_dei_EntityDomain_55059E90ED305F498074E7AAF49D0AE6" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ScheduleOfEarningsPerShareBasicAndDilutedTableTextBlock" xlink:label="loc_us-gaap_ScheduleOfEarningsPerShareBasicAndDilutedTableTextBlock_3BE5F6E2FB705DAE9E418CFED90B8512" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_81E18A24A403572D8F9F29E373233AF6" xlink:to="loc_us-gaap_ScheduleOfEarningsPerShareBasicAndDilutedTableTextBlock_3BE5F6E2FB705DAE9E418CFED90B8512" xlink:type="arc"/>
</link:definitionLink>
<link:definitionLink xlink:role="http://www.pentair.com/role/FinancialStatementsOfParentCompanyGuarantor" xlink:type="extended"/>
<link:definitionLink xlink:role="http://www.pentair.com/role/FinancialStatementsOfParentCompanyGuarantorAdditionalInformationDetail" xlink:type="extended">
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_CondensedFinancialStatementsCaptionsLineItems" xlink:label="loc_us-gaap_CondensedFinancialStatementsCaptionsLineItems_F45890E29E8D5AA4ACA20D31F9E67A4C" xlink:type="locator"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ScheduleOfCondensedFinancialStatementsTable" xlink:label="loc_us-gaap_ScheduleOfCondensedFinancialStatementsTable_00E327C1B0A8522598F0C6DB3DBDC4DD" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_CondensedFinancialStatementsCaptionsLineItems_F45890E29E8D5AA4ACA20D31F9E67A4C" xlink:to="loc_us-gaap_ScheduleOfCondensedFinancialStatementsTable_00E327C1B0A8522598F0C6DB3DBDC4DD" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ConsolidatedEntitiesAxis" xlink:label="loc_us-gaap_ConsolidatedEntitiesAxis_8EC9AEE55FCB597586DA9AEF8488267A" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfCondensedFinancialStatementsTable_00E327C1B0A8522598F0C6DB3DBDC4DD" xlink:to="loc_us-gaap_ConsolidatedEntitiesAxis_8EC9AEE55FCB597586DA9AEF8488267A" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ConsolidatedEntitiesDomain" xlink:label="loc_us-gaap_ConsolidatedEntitiesDomain_BDFE4CF0B3CE6371BE1257C2A286C2E5_E3B43B43A3E7574E8DA0F8529D4EC1C5" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ConsolidatedEntitiesAxis_8EC9AEE55FCB597586DA9AEF8488267A" xlink:to="loc_us-gaap_ConsolidatedEntitiesDomain_BDFE4CF0B3CE6371BE1257C2A286C2E5_E3B43B43A3E7574E8DA0F8529D4EC1C5" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ConsolidatedEntitiesDomain" xlink:label="loc_us-gaap_ConsolidatedEntitiesDomain_012E84DCAD91597D8280E00A7FA20213" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ConsolidatedEntitiesAxis_8EC9AEE55FCB597586DA9AEF8488267A" xlink:to="loc_us-gaap_ConsolidatedEntitiesDomain_012E84DCAD91597D8280E00A7FA20213" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_SubsidiaryIssuerMember" xlink:label="loc_us-gaap_SubsidiaryIssuerMember_87B1F8AEFAC65DF197674C5EA6C2B96E" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConsolidatedEntitiesDomain_012E84DCAD91597D8280E00A7FA20213" xlink:to="loc_us-gaap_SubsidiaryIssuerMember_87B1F8AEFAC65DF197674C5EA6C2B96E" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_VariableInterestEntityOwnershipPercentage" xlink:label="loc_us-gaap_VariableInterestEntityOwnershipPercentage_4FB76E02138C5305B2F93C3B1C048EB5" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CondensedFinancialStatementsCaptionsLineItems_F45890E29E8D5AA4ACA20D31F9E67A4C" xlink:to="loc_us-gaap_VariableInterestEntityOwnershipPercentage_4FB76E02138C5305B2F93C3B1C048EB5" xlink:type="arc"/>
</link:definitionLink>
<link:definitionLink xlink:role="http://www.pentair.com/role/FinancialStatementsOfParentCompanyGuarantorCondensedConsolidatingBalanceSheetDetail" xlink:type="extended">
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_CondensedFinancialStatementsCaptionsLineItems" xlink:label="loc_us-gaap_CondensedFinancialStatementsCaptionsLineItems_6C767CCC2AEE4CB4A46BDC4C90BF75F2" xlink:type="locator"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ScheduleOfCondensedFinancialStatementsTable" xlink:label="loc_us-gaap_ScheduleOfCondensedFinancialStatementsTable_967FB41DE119C2759E90DC4C90BE76DF" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_CondensedFinancialStatementsCaptionsLineItems_6C767CCC2AEE4CB4A46BDC4C90BF75F2" xlink:to="loc_us-gaap_ScheduleOfCondensedFinancialStatementsTable_967FB41DE119C2759E90DC4C90BE76DF" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ConsolidationItemsAxis" xlink:label="loc_us-gaap_ConsolidationItemsAxis_B68CA131012B17AF5110DC4C90BE904E" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfCondensedFinancialStatementsTable_967FB41DE119C2759E90DC4C90BE76DF" xlink:to="loc_us-gaap_ConsolidationItemsAxis_B68CA131012B17AF5110DC4C90BE904E" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ConsolidationItemsDomain" xlink:label="loc_us-gaap_ConsolidationItemsDomain_15BF7B5F14335DC31D98DC4C90BEECD3_default" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ConsolidationItemsAxis_B68CA131012B17AF5110DC4C90BE904E" xlink:to="loc_us-gaap_ConsolidationItemsDomain_15BF7B5F14335DC31D98DC4C90BEECD3_default" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ConsolidationItemsDomain" xlink:label="loc_us-gaap_ConsolidationItemsDomain_15BF7B5F14335DC31D98DC4C90BEECD3" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ConsolidationItemsAxis_B68CA131012B17AF5110DC4C90BE904E" xlink:to="loc_us-gaap_ConsolidationItemsDomain_15BF7B5F14335DC31D98DC4C90BEECD3" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ConsolidationEliminationsMember" xlink:label="loc_us-gaap_ConsolidationEliminationsMember_72512FC91D457E632284DC4C90BF7A66" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConsolidationItemsDomain_15BF7B5F14335DC31D98DC4C90BEECD3" xlink:to="loc_us-gaap_ConsolidationEliminationsMember_72512FC91D457E632284DC4C90BF7A66" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ConsolidatedEntitiesAxis" xlink:label="loc_us-gaap_ConsolidatedEntitiesAxis_DB84AEB35CCF11392FC1DC4C90BF3465" xlink:type="locator"/>
<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfCondensedFinancialStatementsTable_967FB41DE119C2759E90DC4C90BE76DF" xlink:to="loc_us-gaap_ConsolidatedEntitiesAxis_DB84AEB35CCF11392FC1DC4C90BF3465" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ConsolidatedEntitiesDomain" xlink:label="loc_us-gaap_ConsolidatedEntitiesDomain_703C7E5137794CADBCEDDC4C90BFC37D_default" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ConsolidatedEntitiesAxis_DB84AEB35CCF11392FC1DC4C90BF3465" xlink:to="loc_us-gaap_ConsolidatedEntitiesDomain_703C7E5137794CADBCEDDC4C90BFC37D_default" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ConsolidatedEntitiesDomain" xlink:label="loc_us-gaap_ConsolidatedEntitiesDomain_703C7E5137794CADBCEDDC4C90BFC37D" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ConsolidatedEntitiesAxis_DB84AEB35CCF11392FC1DC4C90BF3465" xlink:to="loc_us-gaap_ConsolidatedEntitiesDomain_703C7E5137794CADBCEDDC4C90BFC37D" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ParentCompanyMember" xlink:label="loc_us-gaap_ParentCompanyMember_45A940EC734AFBB639C3DC4C90BF2939" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConsolidatedEntitiesDomain_703C7E5137794CADBCEDDC4C90BFC37D" xlink:to="loc_us-gaap_ParentCompanyMember_45A940EC734AFBB639C3DC4C90BF2939" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_GuarantorSubsidiariesMember" xlink:label="loc_us-gaap_GuarantorSubsidiariesMember_D0C97C838E49AC7468D9DC4C90BFEAAA" xlink:type="locator"/>
<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConsolidatedEntitiesDomain_703C7E5137794CADBCEDDC4C90BFC37D" xlink:to="loc_us-gaap_GuarantorSubsidiariesMember_D0C97C838E49AC7468D9DC4C90BFEAAA" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_SubsidiaryIssuerMember" xlink:label="loc_us-gaap_SubsidiaryIssuerMember_A434FA39F86017A65B68DC4C90BF7DE5" xlink:type="locator"/>
<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConsolidatedEntitiesDomain_703C7E5137794CADBCEDDC4C90BFC37D" xlink:to="loc_us-gaap_SubsidiaryIssuerMember_A434FA39F86017A65B68DC4C90BF7DE5" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_NonGuarantorSubsidiariesMember" xlink:label="loc_us-gaap_NonGuarantorSubsidiariesMember_83457AE2AAC2F8FA6D53DC4C90BFD3FB" xlink:type="locator"/>
<link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConsolidatedEntitiesDomain_703C7E5137794CADBCEDDC4C90BFC37D" xlink:to="loc_us-gaap_NonGuarantorSubsidiariesMember_83457AE2AAC2F8FA6D53DC4C90BFD3FB" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_AssetsCurrentAbstract" xlink:label="loc_us-gaap_AssetsCurrentAbstract_275F526A1F7CC293B249DC4C90BFD536" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CondensedFinancialStatementsCaptionsLineItems_6C767CCC2AEE4CB4A46BDC4C90BF75F2" xlink:to="loc_us-gaap_AssetsCurrentAbstract_275F526A1F7CC293B249DC4C90BFD536" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_CashAndCashEquivalentsAtCarryingValue" xlink:label="loc_us-gaap_CashAndCashEquivalentsAtCarryingValue_0312F7B87A9A46D37BA0DC4C90BFFACF" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsCurrentAbstract_275F526A1F7CC293B249DC4C90BFD536" xlink:to="loc_us-gaap_CashAndCashEquivalentsAtCarryingValue_0312F7B87A9A46D37BA0DC4C90BFFACF" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_AccountsAndNotesReceivableNet" xlink:label="loc_us-gaap_AccountsAndNotesReceivableNet_56775AF3327F2E7E9ECFDC4C90BFF338" xlink:type="locator"/>
<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsCurrentAbstract_275F526A1F7CC293B249DC4C90BFD536" xlink:to="loc_us-gaap_AccountsAndNotesReceivableNet_56775AF3327F2E7E9ECFDC4C90BFF338" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_InventoryNet" xlink:label="loc_us-gaap_InventoryNet_B236BC87673983B6B020DC4C90BF5DC8" xlink:type="locator"/>
<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsCurrentAbstract_275F526A1F7CC293B249DC4C90BFD536" xlink:to="loc_us-gaap_InventoryNet_B236BC87673983B6B020DC4C90BF5DC8" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_OtherAssetsCurrent" xlink:label="loc_us-gaap_OtherAssetsCurrent_08C20DB459FAB65DEFAEDC4C90BFBD53" xlink:type="locator"/>
<link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsCurrentAbstract_275F526A1F7CC293B249DC4C90BFD536" xlink:to="loc_us-gaap_OtherAssetsCurrent_08C20DB459FAB65DEFAEDC4C90BFBD53" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_AssetsCurrent" xlink:label="loc_us-gaap_AssetsCurrent_55C8EF8C67DD3E54B4CFDC4C90BF42EA" xlink:type="locator"/>
<link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsCurrentAbstract_275F526A1F7CC293B249DC4C90BFD536" xlink:to="loc_us-gaap_AssetsCurrent_55C8EF8C67DD3E54B4CFDC4C90BF42EA" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_PropertyPlantAndEquipmentNet" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentNet_AB68DFA6C9A450053B43DC4C90BF9E88" xlink:type="locator"/>
<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CondensedFinancialStatementsCaptionsLineItems_6C767CCC2AEE4CB4A46BDC4C90BF75F2" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentNet_AB68DFA6C9A450053B43DC4C90BF9E88" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_OtherAssetsNoncurrentAbstract" xlink:label="loc_us-gaap_OtherAssetsNoncurrentAbstract_B11331778146C2E7B904DC4C90BFEFCF" xlink:type="locator"/>
<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CondensedFinancialStatementsCaptionsLineItems_6C767CCC2AEE4CB4A46BDC4C90BF75F2" xlink:to="loc_us-gaap_OtherAssetsNoncurrentAbstract_B11331778146C2E7B904DC4C90BFEFCF" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_InvestmentsInAndAdvancesToAffiliatesAmountOfEquity" xlink:label="loc_us-gaap_InvestmentsInAndAdvancesToAffiliatesAmountOfEquity_D78C5933B43CE64380A4DC4C90BF0351" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OtherAssetsNoncurrentAbstract_B11331778146C2E7B904DC4C90BFEFCF" xlink:to="loc_us-gaap_InvestmentsInAndAdvancesToAffiliatesAmountOfEquity_D78C5933B43CE64380A4DC4C90BF0351" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_Goodwill" xlink:label="loc_us-gaap_Goodwill_16BBB9AA90CE83263B3CDC4C90C0B611" xlink:type="locator"/>
<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OtherAssetsNoncurrentAbstract_B11331778146C2E7B904DC4C90BFEFCF" xlink:to="loc_us-gaap_Goodwill_16BBB9AA90CE83263B3CDC4C90C0B611" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_IntangibleAssetsNetExcludingGoodwill" xlink:label="loc_us-gaap_IntangibleAssetsNetExcludingGoodwill_7696D950EFD04496659BDC4C90C069B6" xlink:type="locator"/>
<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OtherAssetsNoncurrentAbstract_B11331778146C2E7B904DC4C90BFEFCF" xlink:to="loc_us-gaap_IntangibleAssetsNetExcludingGoodwill_7696D950EFD04496659BDC4C90C069B6" xlink:type="arc"/>
<link:loc xlink:href="pnr-20180331.xsd#pnr_LongTermIntercompanyDebt" xlink:label="loc_pnr_LongTermIntercompanyDebt_FEF225ECCA49AA8A62D0DC4C90C00880" xlink:type="locator"/>
<link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OtherAssetsNoncurrentAbstract_B11331778146C2E7B904DC4C90BFEFCF" xlink:to="loc_pnr_LongTermIntercompanyDebt_FEF225ECCA49AA8A62D0DC4C90C00880" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_OtherAssetsNoncurrent" xlink:label="loc_us-gaap_OtherAssetsNoncurrent_86928818B5BE0C1ACA6CDC4C90C02AB9" xlink:type="locator"/>
<link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OtherAssetsNoncurrentAbstract_B11331778146C2E7B904DC4C90BFEFCF" xlink:to="loc_us-gaap_OtherAssetsNoncurrent_86928818B5BE0C1ACA6CDC4C90C02AB9" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_AssetsNoncurrent" xlink:label="loc_us-gaap_AssetsNoncurrent_E7ACA7FB465397D29F85DC4C90C052D9" xlink:type="locator"/>
<link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OtherAssetsNoncurrentAbstract_B11331778146C2E7B904DC4C90BFEFCF" xlink:to="loc_us-gaap_AssetsNoncurrent_E7ACA7FB465397D29F85DC4C90C052D9" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_Assets" xlink:label="loc_us-gaap_Assets_E85FD58C5F899B779982DC4C90C03CF5" xlink:type="locator"/>
<link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CondensedFinancialStatementsCaptionsLineItems_6C767CCC2AEE4CB4A46BDC4C90BF75F2" xlink:to="loc_us-gaap_Assets_E85FD58C5F899B779982DC4C90C03CF5" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_LiabilitiesAndStockholdersEquityAbstract" xlink:label="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_EBE4F5484B69B05753E9DC4C90C08C70" xlink:type="locator"/>
<link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CondensedFinancialStatementsCaptionsLineItems_6C767CCC2AEE4CB4A46BDC4C90BF75F2" xlink:to="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_EBE4F5484B69B05753E9DC4C90C08C70" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_LiabilitiesCurrentAbstract" xlink:label="loc_us-gaap_LiabilitiesCurrentAbstract_D9621BE2BF203F1DFA0FDC4C90C0D1B8" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_EBE4F5484B69B05753E9DC4C90C08C70" xlink:to="loc_us-gaap_LiabilitiesCurrentAbstract_D9621BE2BF203F1DFA0FDC4C90C0D1B8" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_LongTermDebtCurrent" xlink:label="loc_us-gaap_LongTermDebtCurrent_12D6F417F8B86527FD30DC4C90C0EF42" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesCurrentAbstract_D9621BE2BF203F1DFA0FDC4C90C0D1B8" xlink:to="loc_us-gaap_LongTermDebtCurrent_12D6F417F8B86527FD30DC4C90C0EF42" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_AccountsPayableCurrent" xlink:label="loc_us-gaap_AccountsPayableCurrent_CC056B3A1ECEE243754EDC4C90C015FB" xlink:type="locator"/>
<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesCurrentAbstract_D9621BE2BF203F1DFA0FDC4C90C0D1B8" xlink:to="loc_us-gaap_AccountsPayableCurrent_CC056B3A1ECEE243754EDC4C90C015FB" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_EmployeeRelatedLiabilitiesCurrent" xlink:label="loc_us-gaap_EmployeeRelatedLiabilitiesCurrent_F3A3228E1ECC0EA6BB13DC4C90C0B5D1" xlink:type="locator"/>
<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesCurrentAbstract_D9621BE2BF203F1DFA0FDC4C90C0D1B8" xlink:to="loc_us-gaap_EmployeeRelatedLiabilitiesCurrent_F3A3228E1ECC0EA6BB13DC4C90C0B5D1" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_OtherAccruedLiabilitiesCurrent" xlink:label="loc_us-gaap_OtherAccruedLiabilitiesCurrent_9F7BA2B44139401C0872DC4C90C0656F" xlink:type="locator"/>
<link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesCurrentAbstract_D9621BE2BF203F1DFA0FDC4C90C0D1B8" xlink:to="loc_us-gaap_OtherAccruedLiabilitiesCurrent_9F7BA2B44139401C0872DC4C90C0656F" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_LiabilitiesCurrent" xlink:label="loc_us-gaap_LiabilitiesCurrent_7957EF8B0F0E43355E7DDC4C90C02D4D" xlink:type="locator"/>
<link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesCurrentAbstract_D9621BE2BF203F1DFA0FDC4C90C0D1B8" xlink:to="loc_us-gaap_LiabilitiesCurrent_7957EF8B0F0E43355E7DDC4C90C02D4D" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_OtherLiabilitiesNoncurrentAbstract" xlink:label="loc_us-gaap_OtherLiabilitiesNoncurrentAbstract_53E03FB06C2050D45E1FDC4C90C04080" xlink:type="locator"/>
<link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CondensedFinancialStatementsCaptionsLineItems_6C767CCC2AEE4CB4A46BDC4C90BF75F2" xlink:to="loc_us-gaap_OtherLiabilitiesNoncurrentAbstract_53E03FB06C2050D45E1FDC4C90C04080" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_LongTermDebtNoncurrent" xlink:label="loc_us-gaap_LongTermDebtNoncurrent_F2FE441D13DFF621C6B6DC4C90C02BBD" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OtherLiabilitiesNoncurrentAbstract_53E03FB06C2050D45E1FDC4C90C04080" xlink:to="loc_us-gaap_LongTermDebtNoncurrent_F2FE441D13DFF621C6B6DC4C90C02BBD" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesNoncurrent" xlink:label="loc_us-gaap_PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesNoncurrent_868B5BC846B4EAF45FD0DC4C90C00A82" xlink:type="locator"/>
<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OtherLiabilitiesNoncurrentAbstract_53E03FB06C2050D45E1FDC4C90C04080" xlink:to="loc_us-gaap_PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesNoncurrent_868B5BC846B4EAF45FD0DC4C90C00A82" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DeferredTaxLiabilitiesNoncurrent" xlink:label="loc_us-gaap_DeferredTaxLiabilitiesNoncurrent_C6FFBCD70B97253C749FDC4C90C063DF" xlink:type="locator"/>
<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OtherLiabilitiesNoncurrentAbstract_53E03FB06C2050D45E1FDC4C90C04080" xlink:to="loc_us-gaap_DeferredTaxLiabilitiesNoncurrent_C6FFBCD70B97253C749FDC4C90C063DF" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_OtherLiabilitiesNoncurrent" xlink:label="loc_us-gaap_OtherLiabilitiesNoncurrent_EE0D98F3C76FDB7A8A0EDC4C90C1122B" xlink:type="locator"/>
<link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OtherLiabilitiesNoncurrentAbstract_53E03FB06C2050D45E1FDC4C90C04080" xlink:to="loc_us-gaap_OtherLiabilitiesNoncurrent_EE0D98F3C76FDB7A8A0EDC4C90C1122B" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_Liabilities" xlink:label="loc_us-gaap_Liabilities_6DD618A81C6DE3C7316DDC4C90C134A7" xlink:type="locator"/>
<link:definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CondensedFinancialStatementsCaptionsLineItems_6C767CCC2AEE4CB4A46BDC4C90BF75F2" xlink:to="loc_us-gaap_Liabilities_6DD618A81C6DE3C7316DDC4C90C134A7" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterestAbstract" xlink:label="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterestAbstract_55C209756CE3FB7987F1DC4C90C1B294" xlink:type="locator"/>
<link:definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CondensedFinancialStatementsCaptionsLineItems_6C767CCC2AEE4CB4A46BDC4C90BF75F2" xlink:to="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterestAbstract_55C209756CE3FB7987F1DC4C90C1B294" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest" xlink:label="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_D24E610CBBD248269E2ADC4C90C1B313" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterestAbstract_55C209756CE3FB7987F1DC4C90C1B294" xlink:to="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_D24E610CBBD248269E2ADC4C90C1B313" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_LiabilitiesAndStockholdersEquity" xlink:label="loc_us-gaap_LiabilitiesAndStockholdersEquity_DEB967180C2CC09CCA46DC4C90C11A3A" xlink:type="locator"/>
<link:definitionArc order="9" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CondensedFinancialStatementsCaptionsLineItems_6C767CCC2AEE4CB4A46BDC4C90BF75F2" xlink:to="loc_us-gaap_LiabilitiesAndStockholdersEquity_DEB967180C2CC09CCA46DC4C90C11A3A" xlink:type="arc"/>
</link:definitionLink>
<link:definitionLink xlink:role="http://www.pentair.com/role/FinancialStatementsOfParentCompanyGuarantorCondensedConsolidatingStatementOfCashFlowsDetail" xlink:type="extended">
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_CondensedFinancialStatementsCaptionsLineItems" xlink:label="loc_us-gaap_CondensedFinancialStatementsCaptionsLineItems_516461CD77046EBFD4A3DBCD91FFC658" xlink:type="locator"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ScheduleOfCondensedFinancialStatementsTable" xlink:label="loc_us-gaap_ScheduleOfCondensedFinancialStatementsTable_5576CB3BB6E2D878C2BBDBCD91FF8996" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_CondensedFinancialStatementsCaptionsLineItems_516461CD77046EBFD4A3DBCD91FFC658" xlink:to="loc_us-gaap_ScheduleOfCondensedFinancialStatementsTable_5576CB3BB6E2D878C2BBDBCD91FF8996" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ConsolidationItemsAxis" xlink:label="loc_us-gaap_ConsolidationItemsAxis_021DE27F7BE087248100DBCD91FFB590" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfCondensedFinancialStatementsTable_5576CB3BB6E2D878C2BBDBCD91FF8996" xlink:to="loc_us-gaap_ConsolidationItemsAxis_021DE27F7BE087248100DBCD91FFB590" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ConsolidationItemsDomain" xlink:label="loc_us-gaap_ConsolidationItemsDomain_9082E2A00F58BAFBFFE3DBCD91FFAB35_default" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ConsolidationItemsAxis_021DE27F7BE087248100DBCD91FFB590" xlink:to="loc_us-gaap_ConsolidationItemsDomain_9082E2A00F58BAFBFFE3DBCD91FFAB35_default" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ConsolidationItemsDomain" xlink:label="loc_us-gaap_ConsolidationItemsDomain_9082E2A00F58BAFBFFE3DBCD91FFAB35" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ConsolidationItemsAxis_021DE27F7BE087248100DBCD91FFB590" xlink:to="loc_us-gaap_ConsolidationItemsDomain_9082E2A00F58BAFBFFE3DBCD91FFAB35" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ConsolidationEliminationsMember" xlink:label="loc_us-gaap_ConsolidationEliminationsMember_5851BF9A200127C86B43DBCD91FFA07A" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConsolidationItemsDomain_9082E2A00F58BAFBFFE3DBCD91FFAB35" xlink:to="loc_us-gaap_ConsolidationEliminationsMember_5851BF9A200127C86B43DBCD91FFA07A" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ConsolidatedEntitiesAxis" xlink:label="loc_us-gaap_ConsolidatedEntitiesAxis_D4D2B4181640F4F80142DBCD91FF543C" xlink:type="locator"/>
<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfCondensedFinancialStatementsTable_5576CB3BB6E2D878C2BBDBCD91FF8996" xlink:to="loc_us-gaap_ConsolidatedEntitiesAxis_D4D2B4181640F4F80142DBCD91FF543C" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ConsolidatedEntitiesDomain" xlink:label="loc_us-gaap_ConsolidatedEntitiesDomain_843C96695C6B3849518ADBCD91FF77B7_default" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ConsolidatedEntitiesAxis_D4D2B4181640F4F80142DBCD91FF543C" xlink:to="loc_us-gaap_ConsolidatedEntitiesDomain_843C96695C6B3849518ADBCD91FF77B7_default" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ConsolidatedEntitiesDomain" xlink:label="loc_us-gaap_ConsolidatedEntitiesDomain_843C96695C6B3849518ADBCD91FF77B7" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ConsolidatedEntitiesAxis_D4D2B4181640F4F80142DBCD91FF543C" xlink:to="loc_us-gaap_ConsolidatedEntitiesDomain_843C96695C6B3849518ADBCD91FF77B7" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ParentCompanyMember" xlink:label="loc_us-gaap_ParentCompanyMember_71D0A38993DDC53AC121DBCD91FF8947" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConsolidatedEntitiesDomain_843C96695C6B3849518ADBCD91FF77B7" xlink:to="loc_us-gaap_ParentCompanyMember_71D0A38993DDC53AC121DBCD91FF8947" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_GuarantorSubsidiariesMember" xlink:label="loc_us-gaap_GuarantorSubsidiariesMember_DC82D5223636B9D2220EDBCD91FFEDBC" xlink:type="locator"/>
<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConsolidatedEntitiesDomain_843C96695C6B3849518ADBCD91FF77B7" xlink:to="loc_us-gaap_GuarantorSubsidiariesMember_DC82D5223636B9D2220EDBCD91FFEDBC" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_SubsidiaryIssuerMember" xlink:label="loc_us-gaap_SubsidiaryIssuerMember_FAD4BC8FF4D88F04B691DBCD91FFFD52" xlink:type="locator"/>
<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConsolidatedEntitiesDomain_843C96695C6B3849518ADBCD91FF77B7" xlink:to="loc_us-gaap_SubsidiaryIssuerMember_FAD4BC8FF4D88F04B691DBCD91FFFD52" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_NonGuarantorSubsidiariesMember" xlink:label="loc_us-gaap_NonGuarantorSubsidiariesMember_1AABE3202B42E2AD932CDBCD91FF8496" xlink:type="locator"/>
<link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConsolidatedEntitiesDomain_843C96695C6B3849518ADBCD91FF77B7" xlink:to="loc_us-gaap_NonGuarantorSubsidiariesMember_1AABE3202B42E2AD932CDBCD91FF8496" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract" xlink:label="loc_us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract_CE8207076CD74A331462DBCD920075C2" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CondensedFinancialStatementsCaptionsLineItems_516461CD77046EBFD4A3DBCD91FFC658" xlink:to="loc_us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract_CE8207076CD74A331462DBCD920075C2" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_NetCashProvidedByUsedInOperatingActivities" xlink:label="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_56D9F9B5B5F0E063E224DBCD9200CE37" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract_CE8207076CD74A331462DBCD920075C2" xlink:to="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_56D9F9B5B5F0E063E224DBCD9200CE37" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract" xlink:label="loc_us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_D4E20840178472E912CBDBCD9200923C" xlink:type="locator"/>
<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CondensedFinancialStatementsCaptionsLineItems_516461CD77046EBFD4A3DBCD91FFC658" xlink:to="loc_us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_D4E20840178472E912CBDBCD9200923C" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_PaymentsToAcquirePropertyPlantAndEquipment" xlink:label="loc_us-gaap_PaymentsToAcquirePropertyPlantAndEquipment_B6AD8E48CDB536C1DBAFDBCD92000FE9" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_D4E20840178472E912CBDBCD9200923C" xlink:to="loc_us-gaap_PaymentsToAcquirePropertyPlantAndEquipment_B6AD8E48CDB536C1DBAFDBCD92000FE9" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ProceedsFromSaleOfPropertyPlantAndEquipment" xlink:label="loc_us-gaap_ProceedsFromSaleOfPropertyPlantAndEquipment_06FA37954EE76DD1490FDBCD9200775A" xlink:type="locator"/>
<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_D4E20840178472E912CBDBCD9200923C" xlink:to="loc_us-gaap_ProceedsFromSaleOfPropertyPlantAndEquipment_06FA37954EE76DD1490FDBCD9200775A" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_PaymentsForProceedsFromBusinessesAndInterestInAffiliates" xlink:label="loc_us-gaap_PaymentsForProceedsFromBusinessesAndInterestInAffiliates_E75520AE930A6BE36485DBCD9200E181" xlink:type="locator"/>
<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_D4E20840178472E912CBDBCD9200923C" xlink:to="loc_us-gaap_PaymentsForProceedsFromBusinessesAndInterestInAffiliates_E75520AE930A6BE36485DBCD9200E181" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_PaymentsToAcquireBusinessesNetOfCashAcquired" xlink:label="loc_us-gaap_PaymentsToAcquireBusinessesNetOfCashAcquired_E5821386D01CCD862C44DBCD9200EB6D" xlink:type="locator"/>
<link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_D4E20840178472E912CBDBCD9200923C" xlink:to="loc_us-gaap_PaymentsToAcquireBusinessesNetOfCashAcquired_E5821386D01CCD862C44DBCD9200EB6D" xlink:type="arc"/>
<link:loc xlink:href="pnr-20180331.xsd#pnr_IntercompanyLoanActivityNet" xlink:label="loc_pnr_IntercompanyLoanActivityNet_4076BB2869D3AA87C07DDBCD9200E29B" xlink:type="locator"/>
<link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_D4E20840178472E912CBDBCD9200923C" xlink:to="loc_pnr_IntercompanyLoanActivityNet_4076BB2869D3AA87C07DDBCD9200E29B" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_NetCashProvidedByUsedInInvestingActivitiesContinuingOperations" xlink:label="loc_us-gaap_NetCashProvidedByUsedInInvestingActivitiesContinuingOperations_C010A0D8076EB50E73D3DBCD92002E6E" xlink:type="locator"/>
<link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_D4E20840178472E912CBDBCD9200923C" xlink:to="loc_us-gaap_NetCashProvidedByUsedInInvestingActivitiesContinuingOperations_C010A0D8076EB50E73D3DBCD92002E6E" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_CashProvidedByUsedInInvestingActivitiesDiscontinuedOperations" xlink:label="loc_us-gaap_CashProvidedByUsedInInvestingActivitiesDiscontinuedOperations_33B1CEFD48E0D563EBE8DBCD92003ED5" xlink:type="locator"/>
<link:definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_D4E20840178472E912CBDBCD9200923C" xlink:to="loc_us-gaap_CashProvidedByUsedInInvestingActivitiesDiscontinuedOperations_33B1CEFD48E0D563EBE8DBCD92003ED5" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_NetCashProvidedByUsedInInvestingActivities" xlink:label="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_F352FF60CC349C281E3EDBCD92002EB8" xlink:type="locator"/>
<link:definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_D4E20840178472E912CBDBCD9200923C" xlink:to="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_F352FF60CC349C281E3EDBCD92002EB8" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract" xlink:label="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_C71F5BAD5DDD8CCC9B13DBCD920033C1" xlink:type="locator"/>
<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CondensedFinancialStatementsCaptionsLineItems_516461CD77046EBFD4A3DBCD91FFC658" xlink:to="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_C71F5BAD5DDD8CCC9B13DBCD920033C1" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ProceedsFromRepaymentsOfShortTermDebt" xlink:label="loc_us-gaap_ProceedsFromRepaymentsOfShortTermDebt_E247C84DC103D129671DDBCD9201FBDC" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_C71F5BAD5DDD8CCC9B13DBCD920033C1" xlink:to="loc_us-gaap_ProceedsFromRepaymentsOfShortTermDebt_E247C84DC103D129671DDBCD9201FBDC" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ProceedsFromRepaymentsOfLinesOfCredit" xlink:label="loc_us-gaap_ProceedsFromRepaymentsOfLinesOfCredit_B137E23F23800BC1A13FDBCD9201573F" xlink:type="locator"/>
<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_C71F5BAD5DDD8CCC9B13DBCD920033C1" xlink:to="loc_us-gaap_ProceedsFromRepaymentsOfLinesOfCredit_B137E23F23800BC1A13FDBCD9201573F" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ProceedsFromIssuanceOfLongTermDebt" xlink:label="loc_us-gaap_ProceedsFromIssuanceOfLongTermDebt_FDB067AA40CC7A17E1D1DBCD92018044" xlink:type="locator"/>
<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_C71F5BAD5DDD8CCC9B13DBCD920033C1" xlink:to="loc_us-gaap_ProceedsFromIssuanceOfLongTermDebt_FDB067AA40CC7A17E1D1DBCD92018044" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_PaymentsOfDebtIssuanceCosts" xlink:label="loc_us-gaap_PaymentsOfDebtIssuanceCosts_05C8DF14AC75D48CB5A4DBCD9201E2FC" xlink:type="locator"/>
<link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_C71F5BAD5DDD8CCC9B13DBCD920033C1" xlink:to="loc_us-gaap_PaymentsOfDebtIssuanceCosts_05C8DF14AC75D48CB5A4DBCD9201E2FC" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ProceedsFromPaymentsForOtherFinancingActivities" xlink:label="loc_us-gaap_ProceedsFromPaymentsForOtherFinancingActivities_AE0B6D843CBEE092E0D8DBCD9201C00B" xlink:type="locator"/>
<link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_C71F5BAD5DDD8CCC9B13DBCD920033C1" xlink:to="loc_us-gaap_ProceedsFromPaymentsForOtherFinancingActivities_AE0B6D843CBEE092E0D8DBCD9201C00B" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ProceedsFromIssuanceOfSharesUnderIncentiveAndShareBasedCompensationPlansIncludingStockOptions" xlink:label="loc_us-gaap_ProceedsFromIssuanceOfSharesUnderIncentiveAndShareBasedCompensationPlansIncludingStockOptions_1EA61E09F2B2402D619DDBCD9201B843" xlink:type="locator"/>
<link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_C71F5BAD5DDD8CCC9B13DBCD920033C1" xlink:to="loc_us-gaap_ProceedsFromIssuanceOfSharesUnderIncentiveAndShareBasedCompensationPlansIncludingStockOptions_1EA61E09F2B2402D619DDBCD9201B843" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_PaymentsForRepurchaseOfCommonStock" xlink:label="loc_us-gaap_PaymentsForRepurchaseOfCommonStock_87173DC95DAA54C662D9DBCD92019B65" xlink:type="locator"/>
<link:definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_C71F5BAD5DDD8CCC9B13DBCD920033C1" xlink:to="loc_us-gaap_PaymentsForRepurchaseOfCommonStock_87173DC95DAA54C662D9DBCD92019B65" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_PaymentsOfDividendsCommonStock" xlink:label="loc_us-gaap_PaymentsOfDividendsCommonStock_21F68ECC8FC30E81E1D4DBCD9201D838" xlink:type="locator"/>
<link:definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_C71F5BAD5DDD8CCC9B13DBCD920033C1" xlink:to="loc_us-gaap_PaymentsOfDividendsCommonStock_21F68ECC8FC30E81E1D4DBCD9201D838" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_NetCashProvidedByUsedInFinancingActivities" xlink:label="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_02EAFAD96386DF35681BDBCD92015DC3" xlink:type="locator"/>
<link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CondensedFinancialStatementsCaptionsLineItems_516461CD77046EBFD4A3DBCD91FFC658" xlink:to="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_02EAFAD96386DF35681BDBCD92015DC3" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_EffectOfExchangeRateOnCashAndCashEquivalents" xlink:label="loc_us-gaap_EffectOfExchangeRateOnCashAndCashEquivalents_AD6C763BCB54A680506FDBCD92012A5E" xlink:type="locator"/>
<link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CondensedFinancialStatementsCaptionsLineItems_516461CD77046EBFD4A3DBCD91FFC658" xlink:to="loc_us-gaap_EffectOfExchangeRateOnCashAndCashEquivalents_AD6C763BCB54A680506FDBCD92012A5E" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_CashAndCashEquivalentsPeriodIncreaseDecrease" xlink:label="loc_us-gaap_CashAndCashEquivalentsPeriodIncreaseDecrease_3A52B735BAF8AF622853DBCD92061AC5" xlink:type="locator"/>
<link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CondensedFinancialStatementsCaptionsLineItems_516461CD77046EBFD4A3DBCD91FFC658" xlink:to="loc_us-gaap_CashAndCashEquivalentsPeriodIncreaseDecrease_3A52B735BAF8AF622853DBCD92061AC5" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_CashAndCashEquivalentsAtCarryingValue" xlink:label="loc_us-gaap_CashAndCashEquivalentsAtCarryingValue_A120505860377AE0D098DBCD920629F6" xlink:type="locator"/>
<link:definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CondensedFinancialStatementsCaptionsLineItems_516461CD77046EBFD4A3DBCD91FFC658" xlink:to="loc_us-gaap_CashAndCashEquivalentsAtCarryingValue_A120505860377AE0D098DBCD920629F6" xlink:type="arc"/>
</link:definitionLink>
<link:definitionLink xlink:role="http://www.pentair.com/role/FinancialStatementsOfParentCompanyGuarantorCondensedConsolidatingStatementOfOperationsAndComprehensiveIncomeLossDetail" xlink:type="extended">
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_CondensedFinancialStatementsCaptionsLineItems" xlink:label="loc_us-gaap_CondensedFinancialStatementsCaptionsLineItems_EF64F5EC61312FDF232EDBCD9241F448" xlink:type="locator"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ScheduleOfCondensedFinancialStatementsTable" xlink:label="loc_us-gaap_ScheduleOfCondensedFinancialStatementsTable_1F977B10F9AC0B533D7ADBCD9240C423" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_CondensedFinancialStatementsCaptionsLineItems_EF64F5EC61312FDF232EDBCD9241F448" xlink:to="loc_us-gaap_ScheduleOfCondensedFinancialStatementsTable_1F977B10F9AC0B533D7ADBCD9240C423" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ConsolidationItemsAxis" xlink:label="loc_us-gaap_ConsolidationItemsAxis_4EC187AC73602BB554F0DBCD9241B2F9" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfCondensedFinancialStatementsTable_1F977B10F9AC0B533D7ADBCD9240C423" xlink:to="loc_us-gaap_ConsolidationItemsAxis_4EC187AC73602BB554F0DBCD9241B2F9" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ConsolidationItemsDomain" xlink:label="loc_us-gaap_ConsolidationItemsDomain_A806E792CA04E1E053DFDBCD9241878C_default" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ConsolidationItemsAxis_4EC187AC73602BB554F0DBCD9241B2F9" xlink:to="loc_us-gaap_ConsolidationItemsDomain_A806E792CA04E1E053DFDBCD9241878C_default" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ConsolidationItemsDomain" xlink:label="loc_us-gaap_ConsolidationItemsDomain_A806E792CA04E1E053DFDBCD9241878C" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ConsolidationItemsAxis_4EC187AC73602BB554F0DBCD9241B2F9" xlink:to="loc_us-gaap_ConsolidationItemsDomain_A806E792CA04E1E053DFDBCD9241878C" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ConsolidationEliminationsMember" xlink:label="loc_us-gaap_ConsolidationEliminationsMember_5C00965100568A8202B9DBCD92410979" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConsolidationItemsDomain_A806E792CA04E1E053DFDBCD9241878C" xlink:to="loc_us-gaap_ConsolidationEliminationsMember_5C00965100568A8202B9DBCD92410979" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ConsolidatedEntitiesAxis" xlink:label="loc_us-gaap_ConsolidatedEntitiesAxis_CA2534E3F4052ACB5FCCDBCD9241BD02" xlink:type="locator"/>
<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfCondensedFinancialStatementsTable_1F977B10F9AC0B533D7ADBCD9240C423" xlink:to="loc_us-gaap_ConsolidatedEntitiesAxis_CA2534E3F4052ACB5FCCDBCD9241BD02" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ConsolidatedEntitiesDomain" xlink:label="loc_us-gaap_ConsolidatedEntitiesDomain_5D46537D6FA0CF6A5803DBCD92418154_default" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ConsolidatedEntitiesAxis_CA2534E3F4052ACB5FCCDBCD9241BD02" xlink:to="loc_us-gaap_ConsolidatedEntitiesDomain_5D46537D6FA0CF6A5803DBCD92418154_default" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ConsolidatedEntitiesDomain" xlink:label="loc_us-gaap_ConsolidatedEntitiesDomain_5D46537D6FA0CF6A5803DBCD92418154" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ConsolidatedEntitiesAxis_CA2534E3F4052ACB5FCCDBCD9241BD02" xlink:to="loc_us-gaap_ConsolidatedEntitiesDomain_5D46537D6FA0CF6A5803DBCD92418154" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ParentCompanyMember" xlink:label="loc_us-gaap_ParentCompanyMember_18A5C8EA8C3E94BE57ECDBCD92411D5D" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConsolidatedEntitiesDomain_5D46537D6FA0CF6A5803DBCD92418154" xlink:to="loc_us-gaap_ParentCompanyMember_18A5C8EA8C3E94BE57ECDBCD92411D5D" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_GuarantorSubsidiariesMember" xlink:label="loc_us-gaap_GuarantorSubsidiariesMember_2B006D9D47F72CA156BCDBCD9241FC00" xlink:type="locator"/>
<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConsolidatedEntitiesDomain_5D46537D6FA0CF6A5803DBCD92418154" xlink:to="loc_us-gaap_GuarantorSubsidiariesMember_2B006D9D47F72CA156BCDBCD9241FC00" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_SubsidiaryIssuerMember" xlink:label="loc_us-gaap_SubsidiaryIssuerMember_C01FFAB79D6FF80ACE2DDBCD92418700" xlink:type="locator"/>
<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConsolidatedEntitiesDomain_5D46537D6FA0CF6A5803DBCD92418154" xlink:to="loc_us-gaap_SubsidiaryIssuerMember_C01FFAB79D6FF80ACE2DDBCD92418700" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_NonGuarantorSubsidiariesMember" xlink:label="loc_us-gaap_NonGuarantorSubsidiariesMember_2C0BA70A4452EA0989CEDBCD92413212" xlink:type="locator"/>
<link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConsolidatedEntitiesDomain_5D46537D6FA0CF6A5803DBCD92418154" xlink:to="loc_us-gaap_NonGuarantorSubsidiariesMember_2C0BA70A4452EA0989CEDBCD92413212" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_SalesRevenueNet" xlink:label="loc_us-gaap_SalesRevenueNet_7157A0BF7121F41E5F0FDBCD92416D81" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CondensedFinancialStatementsCaptionsLineItems_EF64F5EC61312FDF232EDBCD9241F448" xlink:to="loc_us-gaap_SalesRevenueNet_7157A0BF7121F41E5F0FDBCD92416D81" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_CostOfGoodsSold" xlink:label="loc_us-gaap_CostOfGoodsSold_C37BDD3FEB9C35740C47DBCD9247E059" xlink:type="locator"/>
<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CondensedFinancialStatementsCaptionsLineItems_EF64F5EC61312FDF232EDBCD9241F448" xlink:to="loc_us-gaap_CostOfGoodsSold_C37BDD3FEB9C35740C47DBCD9247E059" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_GrossProfit" xlink:label="loc_us-gaap_GrossProfit_527C797EB29D3DE2396DDBCD9247506B" xlink:type="locator"/>
<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CondensedFinancialStatementsCaptionsLineItems_EF64F5EC61312FDF232EDBCD9241F448" xlink:to="loc_us-gaap_GrossProfit_527C797EB29D3DE2396DDBCD9247506B" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_SellingGeneralAndAdministrativeExpense" xlink:label="loc_us-gaap_SellingGeneralAndAdministrativeExpense_31BEC14BD6A9A1C2904CDBCD9247F915" xlink:type="locator"/>
<link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CondensedFinancialStatementsCaptionsLineItems_EF64F5EC61312FDF232EDBCD9241F448" xlink:to="loc_us-gaap_SellingGeneralAndAdministrativeExpense_31BEC14BD6A9A1C2904CDBCD9247F915" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ResearchAndDevelopmentExpense" xlink:label="loc_us-gaap_ResearchAndDevelopmentExpense_1D1770C8710419A21E5BDBCD92474EB0" xlink:type="locator"/>
<link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CondensedFinancialStatementsCaptionsLineItems_EF64F5EC61312FDF232EDBCD9241F448" xlink:to="loc_us-gaap_ResearchAndDevelopmentExpense_1D1770C8710419A21E5BDBCD92474EB0" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_OperatingIncomeLoss" xlink:label="loc_us-gaap_OperatingIncomeLoss_B166D19ADD80CAC34D50DBCD92474D7C" xlink:type="locator"/>
<link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CondensedFinancialStatementsCaptionsLineItems_EF64F5EC61312FDF232EDBCD9241F448" xlink:to="loc_us-gaap_OperatingIncomeLoss_B166D19ADD80CAC34D50DBCD92474D7C" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_GainLossOnInvestments" xlink:label="loc_us-gaap_GainLossOnInvestments_4D003A42E9FD2DAD02F6DBCD92477285" xlink:type="locator"/>
<link:definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CondensedFinancialStatementsCaptionsLineItems_EF64F5EC61312FDF232EDBCD9241F448" xlink:to="loc_us-gaap_GainLossOnInvestments_4D003A42E9FD2DAD02F6DBCD92477285" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_OtherNonoperatingIncomeExpenseAbstract" xlink:label="loc_us-gaap_OtherNonoperatingIncomeExpenseAbstract_9AB3657FD32012EFD008DBCD924713D1" xlink:type="locator"/>
<link:definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CondensedFinancialStatementsCaptionsLineItems_EF64F5EC61312FDF232EDBCD9241F448" xlink:to="loc_us-gaap_OtherNonoperatingIncomeExpenseAbstract_9AB3657FD32012EFD008DBCD924713D1" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_GainLossOnSaleOfBusiness" xlink:label="loc_us-gaap_GainLossOnSaleOfBusiness_135B0C4D3D2A28DB9B6FDBCD92472F3C" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OtherNonoperatingIncomeExpenseAbstract_9AB3657FD32012EFD008DBCD924713D1" xlink:to="loc_us-gaap_GainLossOnSaleOfBusiness_135B0C4D3D2A28DB9B6FDBCD92472F3C" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_InterestIncomeExpenseNet" xlink:label="loc_us-gaap_InterestIncomeExpenseNet_1B50308076434C0C53FEDBCD9247B7DD" xlink:type="locator"/>
<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OtherNonoperatingIncomeExpenseAbstract_9AB3657FD32012EFD008DBCD924713D1" xlink:to="loc_us-gaap_InterestIncomeExpenseNet_1B50308076434C0C53FEDBCD9247B7DD" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_OtherExpenses" xlink:label="loc_us-gaap_OtherExpenses_20C378712B140308240BDBCD924748C9" xlink:type="locator"/>
<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OtherNonoperatingIncomeExpenseAbstract_9AB3657FD32012EFD008DBCD924713D1" xlink:to="loc_us-gaap_OtherExpenses_20C378712B140308240BDBCD924748C9" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest" xlink:label="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_9EB63399AED94CC94C73DBCD924713C2" xlink:type="locator"/>
<link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OtherNonoperatingIncomeExpenseAbstract_9AB3657FD32012EFD008DBCD924713D1" xlink:to="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_9EB63399AED94CC94C73DBCD924713C2" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_IncomeTaxExpenseBenefit" xlink:label="loc_us-gaap_IncomeTaxExpenseBenefit_EC618159DB0D4164EC75DBCD9247E853" xlink:type="locator"/>
<link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OtherNonoperatingIncomeExpenseAbstract_9AB3657FD32012EFD008DBCD924713D1" xlink:to="loc_us-gaap_IncomeTaxExpenseBenefit_EC618159DB0D4164EC75DBCD9247E853" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_IncomeLossFromContinuingOperationsIncludingPortionAttributableToNoncontrollingInterest" xlink:label="loc_us-gaap_IncomeLossFromContinuingOperationsIncludingPortionAttributableToNoncontrollingInterest_EF4914BCBEAC26D40ACEDBCD9247929F" xlink:type="locator"/>
<link:definitionArc order="9" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CondensedFinancialStatementsCaptionsLineItems_EF64F5EC61312FDF232EDBCD9241F448" xlink:to="loc_us-gaap_IncomeLossFromContinuingOperationsIncludingPortionAttributableToNoncontrollingInterest_EF4914BCBEAC26D40ACEDBCD9247929F" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DiscontinuedOperationIncomeLossFromDiscontinuedOperationDuringPhaseOutPeriodNetOfTax" xlink:label="loc_us-gaap_DiscontinuedOperationIncomeLossFromDiscontinuedOperationDuringPhaseOutPeriodNetOfTax_E41430683F5169393793DBCD9248DD3B" xlink:type="locator"/>
<link:definitionArc order="10" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CondensedFinancialStatementsCaptionsLineItems_EF64F5EC61312FDF232EDBCD9241F448" xlink:to="loc_us-gaap_DiscontinuedOperationIncomeLossFromDiscontinuedOperationDuringPhaseOutPeriodNetOfTax_E41430683F5169393793DBCD9248DD3B" xlink:type="arc"/>
<link:loc xlink:href="pnr-20180331.xsd#pnr_DiscontinuedOperationIncomeLossfromInvestmentinSubsidiaries" xlink:label="loc_pnr_DiscontinuedOperationIncomeLossfromInvestmentinSubsidiaries_7F8E2884F73BA4FC79F2DBCD92488EDF" xlink:type="locator"/>
<link:definitionArc order="11" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CondensedFinancialStatementsCaptionsLineItems_EF64F5EC61312FDF232EDBCD9241F448" xlink:to="loc_pnr_DiscontinuedOperationIncomeLossfromInvestmentinSubsidiaries_7F8E2884F73BA4FC79F2DBCD92488EDF" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ComprehensiveIncomeNetOfTaxAbstract" xlink:label="loc_us-gaap_ComprehensiveIncomeNetOfTaxAbstract_226AF950AFD5DA44BC0DDBCD924844C5" xlink:type="locator"/>
<link:definitionArc order="12" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CondensedFinancialStatementsCaptionsLineItems_EF64F5EC61312FDF232EDBCD9241F448" xlink:to="loc_us-gaap_ComprehensiveIncomeNetOfTaxAbstract_226AF950AFD5DA44BC0DDBCD924844C5" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ProfitLoss" xlink:label="loc_us-gaap_ProfitLoss_8C8975F8A54D14192EF7DBCD92486687" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ComprehensiveIncomeNetOfTaxAbstract_226AF950AFD5DA44BC0DDBCD924844C5" xlink:to="loc_us-gaap_ProfitLoss_8C8975F8A54D14192EF7DBCD92486687" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentNetOfTax" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentNetOfTax_467DC45620A030750289DBCD9248B984" xlink:type="locator"/>
<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ComprehensiveIncomeNetOfTaxAbstract_226AF950AFD5DA44BC0DDBCD924844C5" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentNetOfTax_467DC45620A030750289DBCD9248B984" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_OtherComprehensiveIncomeDerivativesQualifyingAsHedgesNetOfTaxPortionAttributableToParent" xlink:label="loc_us-gaap_OtherComprehensiveIncomeDerivativesQualifyingAsHedgesNetOfTaxPortionAttributableToParent_4B120ED8E61A7564B997DBCD9248B202" xlink:type="locator"/>
<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ComprehensiveIncomeNetOfTaxAbstract_226AF950AFD5DA44BC0DDBCD924844C5" xlink:to="loc_us-gaap_OtherComprehensiveIncomeDerivativesQualifyingAsHedgesNetOfTaxPortionAttributableToParent_4B120ED8E61A7564B997DBCD9248B202" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ComprehensiveIncomeNetOfTax" xlink:label="loc_us-gaap_ComprehensiveIncomeNetOfTax_318351E66A6E6D7F3196DBCD9248EA8D" xlink:type="locator"/>
<link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ComprehensiveIncomeNetOfTaxAbstract_226AF950AFD5DA44BC0DDBCD924844C5" xlink:to="loc_us-gaap_ComprehensiveIncomeNetOfTax_318351E66A6E6D7F3196DBCD9248EA8D" xlink:type="arc"/>
</link:definitionLink>
<link:definitionLink xlink:role="http://www.pentair.com/role/FinancialStatementsOfParentCompanyGuarantorTables" xlink:type="extended"/>
<link:definitionLink xlink:role="http://www.pentair.com/role/GoodwillAndOtherIdentifiableIntangibleAssets" xlink:type="extended"/>
<link:definitionLink xlink:role="http://www.pentair.com/role/GoodwillAndOtherIdentifiableIntangibleAssetsAdditionalInformationDetail" xlink:type="extended"/>
<link:definitionLink xlink:role="http://www.pentair.com/role/GoodwillAndOtherIdentifiableIntangibleAssetsChangesInCarryingAmountOfGoodwillBySegmentDetail" xlink:type="extended">
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_GoodwillLineItems" xlink:label="loc_us-gaap_GoodwillLineItems_A63AA14E1DB13546C5EFD9FD1D2E6E69" xlink:type="locator"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ScheduleOfGoodwillTable" xlink:label="loc_us-gaap_ScheduleOfGoodwillTable_C7A09D0B5EC545F39829D9FD1D2DA694" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_GoodwillLineItems_A63AA14E1DB13546C5EFD9FD1D2E6E69" xlink:to="loc_us-gaap_ScheduleOfGoodwillTable_C7A09D0B5EC545F39829D9FD1D2DA694" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_StatementBusinessSegmentsAxis" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_AB09733A42E3EA800D57D9FD1D2DE841" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfGoodwillTable_C7A09D0B5EC545F39829D9FD1D2DA694" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_AB09733A42E3EA800D57D9FD1D2DE841" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_SegmentDomain" xlink:label="loc_us-gaap_SegmentDomain_EBAD98A33C14B78B0A2AD9FD1D2D7D93_default" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_AB09733A42E3EA800D57D9FD1D2DE841" xlink:to="loc_us-gaap_SegmentDomain_EBAD98A33C14B78B0A2AD9FD1D2D7D93_default" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_SegmentDomain" xlink:label="loc_us-gaap_SegmentDomain_EBAD98A33C14B78B0A2AD9FD1D2D7D93" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_AB09733A42E3EA800D57D9FD1D2DE841" xlink:to="loc_us-gaap_SegmentDomain_EBAD98A33C14B78B0A2AD9FD1D2D7D93" xlink:type="arc"/>
<link:loc xlink:href="pnr-20180331.xsd#pnr_WaterUnitMember" xlink:label="loc_pnr_WaterUnitMember_93D8EB360A93461FA602D9FD1D2E7E07" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_EBAD98A33C14B78B0A2AD9FD1D2D7D93" xlink:to="loc_pnr_WaterUnitMember_93D8EB360A93461FA602D9FD1D2E7E07" xlink:type="arc"/>
<link:loc xlink:href="pnr-20180331.xsd#pnr_ElectricalUnitMember" xlink:label="loc_pnr_ElectricalUnitMember_7C64ED536B728D274BECD9FD1D2E66AD" xlink:type="locator"/>
<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_EBAD98A33C14B78B0A2AD9FD1D2D7D93" xlink:to="loc_pnr_ElectricalUnitMember_7C64ED536B728D274BECD9FD1D2E66AD" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_GoodwillRollForward" xlink:label="loc_us-gaap_GoodwillRollForward_C6B4ACC210EAA0EA6651D9FD1D2E8920" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GoodwillLineItems_A63AA14E1DB13546C5EFD9FD1D2E6E69" xlink:to="loc_us-gaap_GoodwillRollForward_C6B4ACC210EAA0EA6651D9FD1D2E8920" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_Goodwill" xlink:label="loc_us-gaap_Goodwill_1D85603DB76B28FD410CD9FD1D2EBF9C" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GoodwillRollForward_C6B4ACC210EAA0EA6651D9FD1D2E8920" xlink:to="loc_us-gaap_Goodwill_1D85603DB76B28FD410CD9FD1D2EBF9C" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_GoodwillOtherIncreaseDecrease" xlink:label="loc_us-gaap_GoodwillOtherIncreaseDecrease_E4043B9F7DCD31F36865D9FD1D2EB897" xlink:type="locator"/>
<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GoodwillRollForward_C6B4ACC210EAA0EA6651D9FD1D2E8920" xlink:to="loc_us-gaap_GoodwillOtherIncreaseDecrease_E4043B9F7DCD31F36865D9FD1D2EB897" xlink:type="arc"/>
</link:definitionLink>
<link:definitionLink xlink:role="http://www.pentair.com/role/GoodwillAndOtherIdentifiableIntangibleAssetsDetailOfIdentifiableIntangibleAssetsDetail" xlink:type="extended">
<link:loc xlink:href="pnr-20180331.xsd#pnr_AcquiredIntangibleAssetsByMajorClassLineItems" xlink:label="loc_pnr_AcquiredIntangibleAssetsByMajorClassLineItems_8247978AB8F5FFBD8D3BCFF412C3DA24" xlink:type="locator"/>
<link:loc xlink:href="pnr-20180331.xsd#pnr_ScheduleOfAcquiredIntangibleAssetsByMajorClassTable" xlink:label="loc_pnr_ScheduleOfAcquiredIntangibleAssetsByMajorClassTable_DE98842F2C36D5D2846DCFF412C366F8" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_pnr_AcquiredIntangibleAssetsByMajorClassLineItems_8247978AB8F5FFBD8D3BCFF412C3DA24" xlink:to="loc_pnr_ScheduleOfAcquiredIntangibleAssetsByMajorClassTable_DE98842F2C36D5D2846DCFF412C366F8" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_F79AEDBA5E64954D1198CFF412C362F0" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_pnr_ScheduleOfAcquiredIntangibleAssetsByMajorClassTable_DE98842F2C36D5D2846DCFF412C366F8" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_F79AEDBA5E64954D1198CFF412C362F0" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_3310185EE15B1F75FF3FCFF412C3D755_default" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_F79AEDBA5E64954D1198CFF412C362F0" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_3310185EE15B1F75FF3FCFF412C3D755_default" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_3310185EE15B1F75FF3FCFF412C3D755" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_F79AEDBA5E64954D1198CFF412C362F0" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_3310185EE15B1F75FF3FCFF412C3D755" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_CustomerRelationshipsMember" xlink:label="loc_us-gaap_CustomerRelationshipsMember_CF94186635516204A950CFF412C31DC7" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_3310185EE15B1F75FF3FCFF412C3D755" xlink:to="loc_us-gaap_CustomerRelationshipsMember_CF94186635516204A950CFF412C31DC7" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_TradeNamesMember" xlink:label="loc_us-gaap_TradeNamesMember_0BF9CC2BD99DFFE0645ACFF412C30FC4" xlink:type="locator"/>
<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_3310185EE15B1F75FF3FCFF412C3D755" xlink:to="loc_us-gaap_TradeNamesMember_0BF9CC2BD99DFFE0645ACFF412C30FC4" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_PatentedTechnologyMember" xlink:label="loc_us-gaap_PatentedTechnologyMember_3A1A13D5074C465D838ACFF412C38B0C" xlink:type="locator"/>
<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_3310185EE15B1F75FF3FCFF412C3D755" xlink:to="loc_us-gaap_PatentedTechnologyMember_3A1A13D5074C465D838ACFF412C38B0C" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsGross" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsGross_4528B2AA2DBE95D326EDCFF412C40BFD" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_pnr_AcquiredIntangibleAssetsByMajorClassLineItems_8247978AB8F5FFBD8D3BCFF412C3DA24" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsGross_4528B2AA2DBE95D326EDCFF412C40BFD" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization_4275F13005BEB4B791B3CFF412C4D9B2" xlink:type="locator"/>
<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_pnr_AcquiredIntangibleAssetsByMajorClassLineItems_8247978AB8F5FFBD8D3BCFF412C3DA24" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization_4275F13005BEB4B791B3CFF412C4D9B2" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsNet" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsNet_D3766B0DF52581D4B2EBCFF412C4C6A7" xlink:type="locator"/>
<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_pnr_AcquiredIntangibleAssetsByMajorClassLineItems_8247978AB8F5FFBD8D3BCFF412C3DA24" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsNet_D3766B0DF52581D4B2EBCFF412C4C6A7" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_IndefiniteLivedIntangibleAssetsExcludingGoodwill" xlink:label="loc_us-gaap_IndefiniteLivedIntangibleAssetsExcludingGoodwill_7CB8DBB35B4FE6A3213BCFF412C423D3" xlink:type="locator"/>
<link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_pnr_AcquiredIntangibleAssetsByMajorClassLineItems_8247978AB8F5FFBD8D3BCFF412C3DA24" xlink:to="loc_us-gaap_IndefiniteLivedIntangibleAssetsExcludingGoodwill_7CB8DBB35B4FE6A3213BCFF412C423D3" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_IntangibleAssetsGrossExcludingGoodwill" xlink:label="loc_us-gaap_IntangibleAssetsGrossExcludingGoodwill_D8B94330109AE111BA32CFF412C4ACE5" xlink:type="locator"/>
<link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_pnr_AcquiredIntangibleAssetsByMajorClassLineItems_8247978AB8F5FFBD8D3BCFF412C3DA24" xlink:to="loc_us-gaap_IntangibleAssetsGrossExcludingGoodwill_D8B94330109AE111BA32CFF412C4ACE5" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_IntangibleAssetsNetExcludingGoodwill" xlink:label="loc_us-gaap_IntangibleAssetsNetExcludingGoodwill_195E86E6481928795FC3CFF412C49833" xlink:type="locator"/>
<link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_pnr_AcquiredIntangibleAssetsByMajorClassLineItems_8247978AB8F5FFBD8D3BCFF412C3DA24" xlink:to="loc_us-gaap_IntangibleAssetsNetExcludingGoodwill_195E86E6481928795FC3CFF412C49833" xlink:type="arc"/>
</link:definitionLink>
<link:definitionLink xlink:role="http://www.pentair.com/role/GoodwillAndOtherIdentifiableIntangibleAssetsEstimatedFutureAmortizationExpenseForIdentifiableIntangibleAssetsDetail" xlink:type="extended"/>
<link:definitionLink xlink:role="http://www.pentair.com/role/GoodwillAndOtherIdentifiableIntangibleAssetsTables" xlink:type="extended"/>
<link:definitionLink xlink:role="http://www.pentair.com/role/IncomeTaxes" xlink:type="extended"/>
<link:definitionLink xlink:role="http://www.pentair.com/role/IncomeTaxesAdditionalInformationDetail" xlink:type="extended">
<link:loc xlink:href="pnr-20180331.xsd#pnr_IncomeTaxesLineItems" xlink:label="loc_pnr_IncomeTaxesLineItems_AE420885611AE4814D24DB6529B1186B" xlink:type="locator"/>
<link:loc xlink:href="pnr-20180331.xsd#pnr_IncomeTaxesTable" xlink:label="loc_pnr_IncomeTaxesTable_449411D254B5399CDEECDB6529B14B3F" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_pnr_IncomeTaxesLineItems_AE420885611AE4814D24DB6529B1186B" xlink:to="loc_pnr_IncomeTaxesTable_449411D254B5399CDEECDB6529B14B3F" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment"/>
<link:loc xlink:href="pnr-20180331.xsd#pnr_IncomeTaxesAxis" xlink:label="loc_pnr_IncomeTaxesAxis_84BDE66349CEEF3F1E78DB6529B109D8" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_pnr_IncomeTaxesTable_449411D254B5399CDEECDB6529B14B3F" xlink:to="loc_pnr_IncomeTaxesAxis_84BDE66349CEEF3F1E78DB6529B109D8" xlink:type="arc"/>
<link:loc xlink:href="pnr-20180331.xsd#pnr_IncomeTaxesDomain" xlink:label="loc_pnr_IncomeTaxesDomain_AECE0CC33C5EE5F354ECDB6529B17B7B_default" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_pnr_IncomeTaxesAxis_84BDE66349CEEF3F1E78DB6529B109D8" xlink:to="loc_pnr_IncomeTaxesDomain_AECE0CC33C5EE5F354ECDB6529B17B7B_default" xlink:type="arc"/>
<link:loc xlink:href="pnr-20180331.xsd#pnr_IncomeTaxesDomain" xlink:label="loc_pnr_IncomeTaxesDomain_AECE0CC33C5EE5F354ECDB6529B17B7B" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_pnr_IncomeTaxesAxis_84BDE66349CEEF3F1E78DB6529B109D8" xlink:to="loc_pnr_IncomeTaxesDomain_AECE0CC33C5EE5F354ECDB6529B17B7B" xlink:type="arc"/>
<link:loc xlink:href="pnr-20180331.xsd#pnr_FederalTaxReformMember" xlink:label="loc_pnr_FederalTaxReformMember_172DC6DF75B8934CA513DB6529B1CA0C" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_pnr_IncomeTaxesDomain_AECE0CC33C5EE5F354ECDB6529B17B7B" xlink:to="loc_pnr_FederalTaxReformMember_172DC6DF75B8934CA513DB6529B1CA0C" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_EffectiveIncomeTaxRateContinuingOperations" xlink:label="loc_us-gaap_EffectiveIncomeTaxRateContinuingOperations_7629A6DFE359C6113479DB6529B1B79B" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_pnr_IncomeTaxesLineItems_AE420885611AE4814D24DB6529B1186B" xlink:to="loc_us-gaap_EffectiveIncomeTaxRateContinuingOperations_7629A6DFE359C6113479DB6529B1B79B" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_UnrecognizedTaxBenefits" xlink:label="loc_us-gaap_UnrecognizedTaxBenefits_8D1534EA2B662B6EB28EDB6529B11461" xlink:type="locator"/>
<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_pnr_IncomeTaxesLineItems_AE420885611AE4814D24DB6529B1186B" xlink:to="loc_us-gaap_UnrecognizedTaxBenefits_8D1534EA2B662B6EB28EDB6529B11461" xlink:type="arc"/>
<link:loc xlink:href="pnr-20180331.xsd#pnr_FederalStatutoryIncomeTaxRateHistorical" xlink:label="loc_pnr_FederalStatutoryIncomeTaxRateHistorical_76EE7C9089DEA188C6ACDB6529B13252" xlink:type="locator"/>
<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_pnr_IncomeTaxesLineItems_AE420885611AE4814D24DB6529B1186B" xlink:to="loc_pnr_FederalStatutoryIncomeTaxRateHistorical_76EE7C9089DEA188C6ACDB6529B13252" xlink:type="arc"/>
<link:loc xlink:href="pnr-20180331.xsd#pnr_TaxCutsandJobsActof2017CorporateFederalTaxRate" xlink:label="loc_pnr_TaxCutsandJobsActof2017CorporateFederalTaxRate_04BA11A7BF2DC5FE6631DB6529B189EA" xlink:type="locator"/>
<link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_pnr_IncomeTaxesLineItems_AE420885611AE4814D24DB6529B1186B" xlink:to="loc_pnr_TaxCutsandJobsActof2017CorporateFederalTaxRate_04BA11A7BF2DC5FE6631DB6529B189EA" xlink:type="arc"/>
<link:loc xlink:href="pnr-20180331.xsd#pnr_Provisionalincometaxbenefit" xlink:label="loc_pnr_Provisionalincometaxbenefit_59AD3641771108FA2098DB6529B1F512" xlink:type="locator"/>
<link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_pnr_IncomeTaxesLineItems_AE420885611AE4814D24DB6529B1186B" xlink:to="loc_pnr_Provisionalincometaxbenefit_59AD3641771108FA2098DB6529B1F512" xlink:type="arc"/>
<link:loc xlink:href="pnr-20180331.xsd#pnr_Decreaseofincometaxexpenserelatedtoremeasurementofcertaindeferredtaxassetsandliabilitiesduetolowertaxrate" xlink:label="loc_pnr_Decreaseofincometaxexpenserelatedtoremeasurementofcertaindeferredtaxassetsandliabilitiesduetolowertaxrate_BC91B63FE6867E275665DB6529B1C6C8" xlink:type="locator"/>
<link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_pnr_IncomeTaxesLineItems_AE420885611AE4814D24DB6529B1186B" xlink:to="loc_pnr_Decreaseofincometaxexpenserelatedtoremeasurementofcertaindeferredtaxassetsandliabilitiesduetolowertaxrate_BC91B63FE6867E275665DB6529B1C6C8" xlink:type="arc"/>
<link:loc xlink:href="pnr-20180331.xsd#pnr_Transitiontaxexpense" xlink:label="loc_pnr_Transitiontaxexpense_B06396E5A82A1D75FEA3DB6529B1397D" xlink:type="locator"/>
<link:definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_pnr_IncomeTaxesLineItems_AE420885611AE4814D24DB6529B1186B" xlink:to="loc_pnr_Transitiontaxexpense_B06396E5A82A1D75FEA3DB6529B1397D" xlink:type="arc"/>
</link:definitionLink>
<link:definitionLink xlink:role="http://www.pentair.com/role/Restructuring" xlink:type="extended"/>
<link:definitionLink xlink:role="http://www.pentair.com/role/RestructuringAdditionalInformationDetail" xlink:type="extended">
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_RestructuringCostAndReserveLineItems" xlink:label="loc_us-gaap_RestructuringCostAndReserveLineItems_B68EBC62FC4E876DD7ECD43B465F6015" xlink:type="locator"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ScheduleOfRestructuringAndRelatedCostsTable" xlink:label="loc_us-gaap_ScheduleOfRestructuringAndRelatedCostsTable_CDBB84446049C303B4AED43B465F953F" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_RestructuringCostAndReserveLineItems_B68EBC62FC4E876DD7ECD43B465F6015" xlink:to="loc_us-gaap_ScheduleOfRestructuringAndRelatedCostsTable_CDBB84446049C303B4AED43B465F953F" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_StatementBusinessSegmentsAxis" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_7B512EDE0A65C0B2C04AD43B465FEFB5" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfRestructuringAndRelatedCostsTable_CDBB84446049C303B4AED43B465F953F" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_7B512EDE0A65C0B2C04AD43B465FEFB5" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_SegmentDomain" xlink:label="loc_us-gaap_SegmentDomain_BC713450F1BBF8BD26F4D43B465F5E23_default" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_7B512EDE0A65C0B2C04AD43B465FEFB5" xlink:to="loc_us-gaap_SegmentDomain_BC713450F1BBF8BD26F4D43B465F5E23_default" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_SegmentDomain" xlink:label="loc_us-gaap_SegmentDomain_BC713450F1BBF8BD26F4D43B465F5E23" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_7B512EDE0A65C0B2C04AD43B465FEFB5" xlink:to="loc_us-gaap_SegmentDomain_BC713450F1BBF8BD26F4D43B465F5E23" xlink:type="arc"/>
<link:loc xlink:href="pnr-20180331.xsd#pnr_WaterUnitMember" xlink:label="loc_pnr_WaterUnitMember_A14100E7CE95D5DA1E92D43B465F1225" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_BC713450F1BBF8BD26F4D43B465F5E23" xlink:to="loc_pnr_WaterUnitMember_A14100E7CE95D5DA1E92D43B465F1225" xlink:type="arc"/>
<link:loc xlink:href="pnr-20180331.xsd#pnr_ElectricalUnitMember" xlink:label="loc_pnr_ElectricalUnitMember_7A6EB61A07DA6338C42ED43B465FF56F" xlink:type="locator"/>
<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_BC713450F1BBF8BD26F4D43B465F5E23" xlink:to="loc_pnr_ElectricalUnitMember_7A6EB61A07DA6338C42ED43B465FF56F" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_CorporateAndOtherMember" xlink:label="loc_us-gaap_CorporateAndOtherMember_B4BE130797E753E8748ED43B465FBC45" xlink:type="locator"/>
<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_BC713450F1BBF8BD26F4D43B465F5E23" xlink:to="loc_us-gaap_CorporateAndOtherMember_B4BE130797E753E8748ED43B465FBC45" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_RestructuringAndRelatedCostNumberOfPositionsEliminated" xlink:label="loc_us-gaap_RestructuringAndRelatedCostNumberOfPositionsEliminated_7AA8EBA135B228575074D43B465F248A" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestructuringCostAndReserveLineItems_B68EBC62FC4E876DD7ECD43B465F6015" xlink:to="loc_us-gaap_RestructuringAndRelatedCostNumberOfPositionsEliminated_7AA8EBA135B228575074D43B465F248A" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_RestructuringCharges" xlink:label="loc_us-gaap_RestructuringCharges_D35FE721C71411F731D8D43B465FFFC0" xlink:type="locator"/>
<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestructuringCostAndReserveLineItems_B68EBC62FC4E876DD7ECD43B465F6015" xlink:to="loc_us-gaap_RestructuringCharges_D35FE721C71411F731D8D43B465FFFC0" xlink:type="arc"/>
</link:definitionLink>
<link:definitionLink xlink:role="http://www.pentair.com/role/RestructuringRestructuringAccrualActivityRecordedOnCondensedConsolidatedBalanceSheetsDetail" xlink:type="extended"/>
<link:definitionLink xlink:role="http://www.pentair.com/role/RestructuringRestructuringRelatedCostsIncludedInSellingGeneralAdministrativeExpensesOnConsolidatedStatementsOfIncomeDetail" xlink:type="extended">
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_RestructuringCostAndReserveLineItems" xlink:label="loc_us-gaap_RestructuringCostAndReserveLineItems_8495BE0066F028EB5CE9CFF4135D97E4" xlink:type="locator"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ScheduleOfRestructuringAndRelatedCostsTable" xlink:label="loc_us-gaap_ScheduleOfRestructuringAndRelatedCostsTable_428387CD29BA2062CB21CFF4135C70CB" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_RestructuringCostAndReserveLineItems_8495BE0066F028EB5CE9CFF4135D97E4" xlink:to="loc_us-gaap_ScheduleOfRestructuringAndRelatedCostsTable_428387CD29BA2062CB21CFF4135C70CB" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_RestructuringCostAndReserveAxis" xlink:label="loc_us-gaap_RestructuringCostAndReserveAxis_C58E0E097C0FF180A972CFF4135DB233" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfRestructuringAndRelatedCostsTable_428387CD29BA2062CB21CFF4135C70CB" xlink:to="loc_us-gaap_RestructuringCostAndReserveAxis_C58E0E097C0FF180A972CFF4135DB233" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_TypeOfRestructuringDomain" xlink:label="loc_us-gaap_TypeOfRestructuringDomain_FE79A3AFE155BFD7E30ACFF4135DB0B0_default" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RestructuringCostAndReserveAxis_C58E0E097C0FF180A972CFF4135DB233" xlink:to="loc_us-gaap_TypeOfRestructuringDomain_FE79A3AFE155BFD7E30ACFF4135DB0B0_default" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_TypeOfRestructuringDomain" xlink:label="loc_us-gaap_TypeOfRestructuringDomain_FE79A3AFE155BFD7E30ACFF4135DB0B0" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RestructuringCostAndReserveAxis_C58E0E097C0FF180A972CFF4135DB233" xlink:to="loc_us-gaap_TypeOfRestructuringDomain_FE79A3AFE155BFD7E30ACFF4135DB0B0" xlink:type="arc"/>
<link:loc xlink:href="pnr-20180331.xsd#pnr_SeveranceAndRelatedCostsMember" xlink:label="loc_pnr_SeveranceAndRelatedCostsMember_1EC5F7E1F4C56E7D7D1FCFF4135DA99A" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TypeOfRestructuringDomain_FE79A3AFE155BFD7E30ACFF4135DB0B0" xlink:to="loc_pnr_SeveranceAndRelatedCostsMember_1EC5F7E1F4C56E7D7D1FCFF4135DA99A" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_OtherRestructuringMember" xlink:label="loc_us-gaap_OtherRestructuringMember_928959DCE2717FCB90EBCFF4135DB5D2" xlink:type="locator"/>
<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TypeOfRestructuringDomain_FE79A3AFE155BFD7E30ACFF4135DB0B0" xlink:to="loc_us-gaap_OtherRestructuringMember_928959DCE2717FCB90EBCFF4135DB5D2" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_RestructuringCharges" xlink:label="loc_us-gaap_RestructuringCharges_EBD26715F3AEEF49B1CDCFF4135D7A68" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestructuringCostAndReserveLineItems_8495BE0066F028EB5CE9CFF4135D97E4" xlink:to="loc_us-gaap_RestructuringCharges_EBD26715F3AEEF49B1CDCFF4135D7A68" xlink:type="arc"/>
</link:definitionLink>
<link:definitionLink xlink:role="http://www.pentair.com/role/RestructuringTables" xlink:type="extended"/>
<link:definitionLink xlink:role="http://www.pentair.com/role/Revenue" xlink:type="extended"/>
<link:definitionLink xlink:role="http://www.pentair.com/role/RevenueAdditionalInformationDetails" xlink:type="extended">
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DisaggregationOfRevenueLineItems" xlink:label="loc_us-gaap_DisaggregationOfRevenueLineItems_2E256A1FA086AF2E17C2D923AA5F9F8C" xlink:type="locator"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DisaggregationOfRevenueTable" xlink:label="loc_us-gaap_DisaggregationOfRevenueTable_8FB7026977A82F4CFA58D923AA5F1286" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DisaggregationOfRevenueLineItems_2E256A1FA086AF2E17C2D923AA5F9F8C" xlink:to="loc_us-gaap_DisaggregationOfRevenueTable_8FB7026977A82F4CFA58D923AA5F1286" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_TimingOfTransferOfGoodOrServiceAxis" xlink:label="loc_us-gaap_TimingOfTransferOfGoodOrServiceAxis_E787476643528C8A9A68D923AA5F6B84" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DisaggregationOfRevenueTable_8FB7026977A82F4CFA58D923AA5F1286" xlink:to="loc_us-gaap_TimingOfTransferOfGoodOrServiceAxis_E787476643528C8A9A68D923AA5F6B84" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_TimingOfTransferOfGoodOrServiceDomain" xlink:label="loc_us-gaap_TimingOfTransferOfGoodOrServiceDomain_A29E6586DBC9F3EAA200D923AA5F258E_default" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_TimingOfTransferOfGoodOrServiceAxis_E787476643528C8A9A68D923AA5F6B84" xlink:to="loc_us-gaap_TimingOfTransferOfGoodOrServiceDomain_A29E6586DBC9F3EAA200D923AA5F258E_default" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_TimingOfTransferOfGoodOrServiceDomain" xlink:label="loc_us-gaap_TimingOfTransferOfGoodOrServiceDomain_A29E6586DBC9F3EAA200D923AA5F258E" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_TimingOfTransferOfGoodOrServiceAxis_E787476643528C8A9A68D923AA5F6B84" xlink:to="loc_us-gaap_TimingOfTransferOfGoodOrServiceDomain_A29E6586DBC9F3EAA200D923AA5F258E" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_TransferredAtPointInTimeMember" xlink:label="loc_us-gaap_TransferredAtPointInTimeMember_F93C6027F6C7DC3CBCE3D923AA5F1104" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TimingOfTransferOfGoodOrServiceDomain_A29E6586DBC9F3EAA200D923AA5F258E" xlink:to="loc_us-gaap_TransferredAtPointInTimeMember_F93C6027F6C7DC3CBCE3D923AA5F1104" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_TransferredOverTimeMember" xlink:label="loc_us-gaap_TransferredOverTimeMember_783BC5CAB28FEBEBE7BDD923AA5FE8F6" xlink:type="locator"/>
<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TimingOfTransferOfGoodOrServiceDomain_A29E6586DBC9F3EAA200D923AA5F258E" xlink:to="loc_us-gaap_TransferredOverTimeMember_783BC5CAB28FEBEBE7BDD923AA5FE8F6" xlink:type="arc"/>
<link:loc xlink:href="pnr-20180331.xsd#pnr_ContractwithCustomerLiabilityRevenueRecognizedPercent" xlink:label="loc_pnr_ContractwithCustomerLiabilityRevenueRecognizedPercent_5D34E4863461591195FAD93096459283" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DisaggregationOfRevenueLineItems_2E256A1FA086AF2E17C2D923AA5F9F8C" xlink:to="loc_pnr_ContractwithCustomerLiabilityRevenueRecognizedPercent_5D34E4863461591195FAD93096459283" xlink:type="arc"/>
<link:loc xlink:href="pnr-20180331.xsd#pnr_RevenuesPercent" xlink:label="loc_pnr_RevenuesPercent_FC5A59B72BCE86871390D923AA5FCDF5" xlink:type="locator"/>
<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DisaggregationOfRevenueLineItems_2E256A1FA086AF2E17C2D923AA5F9F8C" xlink:to="loc_pnr_RevenuesPercent_FC5A59B72BCE86871390D923AA5FCDF5" xlink:type="arc"/>
</link:definitionLink>
<link:definitionLink xlink:role="http://www.pentair.com/role/RevenueGeographicNetSalesInformationBySegmentDetails" xlink:type="extended">
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DisaggregationOfRevenueLineItems" xlink:label="loc_us-gaap_DisaggregationOfRevenueLineItems_4959F6773EF4F561FE5DDA59AFAC55F8" xlink:type="locator"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DisaggregationOfRevenueTable" xlink:label="loc_us-gaap_DisaggregationOfRevenueTable_733779E501C9BF789CADDA59AFA9479B" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DisaggregationOfRevenueLineItems_4959F6773EF4F561FE5DDA59AFAC55F8" xlink:to="loc_us-gaap_DisaggregationOfRevenueTable_733779E501C9BF789CADDA59AFA9479B" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_StatementBusinessSegmentsAxis" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_91725D8964499D09ABF5DA59AFA9B630" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DisaggregationOfRevenueTable_733779E501C9BF789CADDA59AFA9479B" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_91725D8964499D09ABF5DA59AFA9B630" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_SegmentDomain" xlink:label="loc_us-gaap_SegmentDomain_90974035133C5AEC7F9CDA59AFA97EE0_default" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_91725D8964499D09ABF5DA59AFA9B630" xlink:to="loc_us-gaap_SegmentDomain_90974035133C5AEC7F9CDA59AFA97EE0_default" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_SegmentDomain" xlink:label="loc_us-gaap_SegmentDomain_90974035133C5AEC7F9CDA59AFA97EE0" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_91725D8964499D09ABF5DA59AFA9B630" xlink:to="loc_us-gaap_SegmentDomain_90974035133C5AEC7F9CDA59AFA97EE0" xlink:type="arc"/>
<link:loc xlink:href="pnr-20180331.xsd#pnr_WaterUnitMember" xlink:label="loc_pnr_WaterUnitMember_528906EB63AFE3082E84DA59AFA90226" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_90974035133C5AEC7F9CDA59AFA97EE0" xlink:to="loc_pnr_WaterUnitMember_528906EB63AFE3082E84DA59AFA90226" xlink:type="arc"/>
<link:loc xlink:href="pnr-20180331.xsd#pnr_ElectricalUnitMember" xlink:label="loc_pnr_ElectricalUnitMember_8170E3085D29B8D909BADA59AFAADD9E" xlink:type="locator"/>
<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_90974035133C5AEC7F9CDA59AFA97EE0" xlink:to="loc_pnr_ElectricalUnitMember_8170E3085D29B8D909BADA59AFAADD9E" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_AllOtherSegmentsMember" xlink:label="loc_us-gaap_AllOtherSegmentsMember_ABAE4386DEADE725F839DA59AFAB9D18" xlink:type="locator"/>
<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_90974035133C5AEC7F9CDA59AFA97EE0" xlink:to="loc_us-gaap_AllOtherSegmentsMember_ABAE4386DEADE725F839DA59AFAB9D18" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_StatementGeographicalAxis" xlink:label="loc_us-gaap_StatementGeographicalAxis_01577CA3B15CC822DD8ADA59AFAA91A2" xlink:type="locator"/>
<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DisaggregationOfRevenueTable_733779E501C9BF789CADDA59AFA9479B" xlink:to="loc_us-gaap_StatementGeographicalAxis_01577CA3B15CC822DD8ADA59AFAA91A2" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_SegmentGeographicalDomain" xlink:label="loc_us-gaap_SegmentGeographicalDomain_E52083B9DFCF6625C5E5DA59AFAAC209_default" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementGeographicalAxis_01577CA3B15CC822DD8ADA59AFAA91A2" xlink:to="loc_us-gaap_SegmentGeographicalDomain_E52083B9DFCF6625C5E5DA59AFAAC209_default" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_SegmentGeographicalDomain" xlink:label="loc_us-gaap_SegmentGeographicalDomain_E52083B9DFCF6625C5E5DA59AFAAC209" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementGeographicalAxis_01577CA3B15CC822DD8ADA59AFAA91A2" xlink:to="loc_us-gaap_SegmentGeographicalDomain_E52083B9DFCF6625C5E5DA59AFAAC209" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.sec.gov/country/2017/country-2017-01-31.xsd#country_US" xlink:label="loc_country_US_B46614E8D2FF1A740711DA59AFAA5DFC" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentGeographicalDomain_E52083B9DFCF6625C5E5DA59AFAAC209" xlink:to="loc_country_US_B46614E8D2FF1A740711DA59AFAA5DFC" xlink:type="arc"/>
<link:loc xlink:href="pnr-20180331.xsd#pnr_WesternEuropeMember" xlink:label="loc_pnr_WesternEuropeMember_97918E363BEA9FD17AC8DA59AFAADBBE" xlink:type="locator"/>
<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentGeographicalDomain_E52083B9DFCF6625C5E5DA59AFAAC209" xlink:to="loc_pnr_WesternEuropeMember_97918E363BEA9FD17AC8DA59AFAADBBE" xlink:type="arc"/>
<link:loc xlink:href="pnr-20180331.xsd#pnr_DevelopingCountriesMember" xlink:label="loc_pnr_DevelopingCountriesMember_7E4FE4F4344D9F26CC46DA59AFAA42A1" xlink:type="locator"/>
<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentGeographicalDomain_E52083B9DFCF6625C5E5DA59AFAAC209" xlink:to="loc_pnr_DevelopingCountriesMember_7E4FE4F4344D9F26CC46DA59AFAA42A1" xlink:type="arc"/>
<link:loc xlink:href="pnr-20180331.xsd#pnr_OtherDevelopedCountriesMember" xlink:label="loc_pnr_OtherDevelopedCountriesMember_E6D69FC795448CA06678DA59AFAA9BC7" xlink:type="locator"/>
<link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentGeographicalDomain_E52083B9DFCF6625C5E5DA59AFAAC209" xlink:to="loc_pnr_OtherDevelopedCountriesMember_E6D69FC795448CA06678DA59AFAA9BC7" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_EquitySecuritiesByIndustryAxis" xlink:label="loc_us-gaap_EquitySecuritiesByIndustryAxis_BD51BFA52A153D88F58BDA59AFAAA002" xlink:type="locator"/>
<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DisaggregationOfRevenueTable_733779E501C9BF789CADDA59AFA9479B" xlink:to="loc_us-gaap_EquitySecuritiesByIndustryAxis_BD51BFA52A153D88F58BDA59AFAAA002" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_EquitySecuritiesIndustryMember" xlink:label="loc_us-gaap_EquitySecuritiesIndustryMember_3B0215F488E77B59069CDA59AFAAD131_default" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_EquitySecuritiesByIndustryAxis_BD51BFA52A153D88F58BDA59AFAAA002" xlink:to="loc_us-gaap_EquitySecuritiesIndustryMember_3B0215F488E77B59069CDA59AFAAD131_default" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_EquitySecuritiesIndustryMember" xlink:label="loc_us-gaap_EquitySecuritiesIndustryMember_3B0215F488E77B59069CDA59AFAAD131" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_EquitySecuritiesByIndustryAxis_BD51BFA52A153D88F58BDA59AFAAA002" xlink:to="loc_us-gaap_EquitySecuritiesIndustryMember_3B0215F488E77B59069CDA59AFAAD131" xlink:type="arc"/>
<link:loc xlink:href="pnr-20180331.xsd#pnr_ResidentialSectorMember" xlink:label="loc_pnr_ResidentialSectorMember_4857B8444E0582F4694EDA59AFAAA7E3" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquitySecuritiesIndustryMember_3B0215F488E77B59069CDA59AFAAD131" xlink:to="loc_pnr_ResidentialSectorMember_4857B8444E0582F4694EDA59AFAAA7E3" xlink:type="arc"/>
<link:loc xlink:href="pnr-20180331.xsd#pnr_CommercialSectorMember" xlink:label="loc_pnr_CommercialSectorMember_75D7260BA941BF3B20A0DA59AFAAD870" xlink:type="locator"/>
<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquitySecuritiesIndustryMember_3B0215F488E77B59069CDA59AFAAD131" xlink:to="loc_pnr_CommercialSectorMember_75D7260BA941BF3B20A0DA59AFAAD870" xlink:type="arc"/>
<link:loc xlink:href="pnr-20180331.xsd#pnr_IndustrialSectorMember" xlink:label="loc_pnr_IndustrialSectorMember_3AA641D5EBAAC049A86ADA59AFAB71B0" xlink:type="locator"/>
<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquitySecuritiesIndustryMember_3B0215F488E77B59069CDA59AFAAD131" xlink:to="loc_pnr_IndustrialSectorMember_3AA641D5EBAAC049A86ADA59AFAB71B0" xlink:type="arc"/>
<link:loc xlink:href="pnr-20180331.xsd#pnr_CommercialAndResidentialSectorMember" xlink:label="loc_pnr_CommercialAndResidentialSectorMember_6DC07E3DA5C848CA8A3EDA59AFAB94C3" xlink:type="locator"/>
<link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquitySecuritiesIndustryMember_3B0215F488E77B59069CDA59AFAAD131" xlink:to="loc_pnr_CommercialAndResidentialSectorMember_6DC07E3DA5C848CA8A3EDA59AFAB94C3" xlink:type="arc"/>
<link:loc xlink:href="pnr-20180331.xsd#pnr_EnergySectorMember" xlink:label="loc_pnr_EnergySectorMember_89A4C5AFEA0B389C16DADA59AFABF28D" xlink:type="locator"/>
<link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquitySecuritiesIndustryMember_3B0215F488E77B59069CDA59AFAAD131" xlink:to="loc_pnr_EnergySectorMember_89A4C5AFEA0B389C16DADA59AFABF28D" xlink:type="arc"/>
<link:loc xlink:href="pnr-20180331.xsd#pnr_InfrastructureSectorMember" xlink:label="loc_pnr_InfrastructureSectorMember_37B09D665FF1A54AC4DEDA59AFABE91F" xlink:type="locator"/>
<link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquitySecuritiesIndustryMember_3B0215F488E77B59069CDA59AFAAD131" xlink:to="loc_pnr_InfrastructureSectorMember_37B09D665FF1A54AC4DEDA59AFABE91F" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ConsolidationItemsAxis" xlink:label="loc_us-gaap_ConsolidationItemsAxis_34664155120237341AD5DA59AFABC987" xlink:type="locator"/>
<link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DisaggregationOfRevenueTable_733779E501C9BF789CADDA59AFA9479B" xlink:to="loc_us-gaap_ConsolidationItemsAxis_34664155120237341AD5DA59AFABC987" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ConsolidationItemsDomain" xlink:label="loc_us-gaap_ConsolidationItemsDomain_C5B06BC6DD8994B54AE6DA59AFAB5393_default" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ConsolidationItemsAxis_34664155120237341AD5DA59AFABC987" xlink:to="loc_us-gaap_ConsolidationItemsDomain_C5B06BC6DD8994B54AE6DA59AFAB5393_default" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ConsolidationItemsDomain" xlink:label="loc_us-gaap_ConsolidationItemsDomain_C5B06BC6DD8994B54AE6DA59AFAB5393" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ConsolidationItemsAxis_34664155120237341AD5DA59AFABC987" xlink:to="loc_us-gaap_ConsolidationItemsDomain_C5B06BC6DD8994B54AE6DA59AFAB5393" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_OperatingSegmentsMember" xlink:label="loc_us-gaap_OperatingSegmentsMember_79935CE37EBDB3DEBD60DA59AFABDBCB" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConsolidationItemsDomain_C5B06BC6DD8994B54AE6DA59AFAB5393" xlink:to="loc_us-gaap_OperatingSegmentsMember_79935CE37EBDB3DEBD60DA59AFABDBCB" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ProductOrServiceAxis" xlink:label="loc_us-gaap_ProductOrServiceAxis_375A62B4E9FA70EF9B26DA59AFABDE69" xlink:type="locator"/>
<link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DisaggregationOfRevenueTable_733779E501C9BF789CADDA59AFA9479B" xlink:to="loc_us-gaap_ProductOrServiceAxis_375A62B4E9FA70EF9B26DA59AFABDE69" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ProductsAndServicesDomain" xlink:label="loc_us-gaap_ProductsAndServicesDomain_3C2B0116C78BDB2D4059DA59AFABCC3C_default" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ProductOrServiceAxis_375A62B4E9FA70EF9B26DA59AFABDE69" xlink:to="loc_us-gaap_ProductsAndServicesDomain_3C2B0116C78BDB2D4059DA59AFABCC3C_default" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ProductsAndServicesDomain" xlink:label="loc_us-gaap_ProductsAndServicesDomain_3C2B0116C78BDB2D4059DA59AFABCC3C" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ProductOrServiceAxis_375A62B4E9FA70EF9B26DA59AFABDE69" xlink:to="loc_us-gaap_ProductsAndServicesDomain_3C2B0116C78BDB2D4059DA59AFABCC3C" xlink:type="arc"/>
<link:loc xlink:href="pnr-20180331.xsd#pnr_AquaticSystemsMember" xlink:label="loc_pnr_AquaticSystemsMember_E9530F38F966D029910FDA59AFAB8095" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ProductsAndServicesDomain_3C2B0116C78BDB2D4059DA59AFABCC3C" xlink:to="loc_pnr_AquaticSystemsMember_E9530F38F966D029910FDA59AFAB8095" xlink:type="arc"/>
<link:loc xlink:href="pnr-20180331.xsd#pnr_FiltrationSolutionsMember" xlink:label="loc_pnr_FiltrationSolutionsMember_12FE647229189A2FE042DA59AFACA605" xlink:type="locator"/>
<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ProductsAndServicesDomain_3C2B0116C78BDB2D4059DA59AFABCC3C" xlink:to="loc_pnr_FiltrationSolutionsMember_12FE647229189A2FE042DA59AFACA605" xlink:type="arc"/>
<link:loc xlink:href="pnr-20180331.xsd#pnr_FlowTechnologiesMember" xlink:label="loc_pnr_FlowTechnologiesMember_5C1E080BA1A00196F3EADA59AFAC2C2E" xlink:type="locator"/>
<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ProductsAndServicesDomain_3C2B0116C78BDB2D4059DA59AFABCC3C" xlink:to="loc_pnr_FlowTechnologiesMember_5C1E080BA1A00196F3EADA59AFAC2C2E" xlink:type="arc"/>
<link:loc xlink:href="pnr-20180331.xsd#pnr_EnclosuresMember" xlink:label="loc_pnr_EnclosuresMember_437DCAA67D1CF88F285EDA59AFAC1E9B" xlink:type="locator"/>
<link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ProductsAndServicesDomain_3C2B0116C78BDB2D4059DA59AFABCC3C" xlink:to="loc_pnr_EnclosuresMember_437DCAA67D1CF88F285EDA59AFAC1E9B" xlink:type="arc"/>
<link:loc xlink:href="pnr-20180331.xsd#pnr_ThermalManagementMember" xlink:label="loc_pnr_ThermalManagementMember_D8188488D68EB6A41F4FDA59AFAC3824" xlink:type="locator"/>
<link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ProductsAndServicesDomain_3C2B0116C78BDB2D4059DA59AFABCC3C" xlink:to="loc_pnr_ThermalManagementMember_D8188488D68EB6A41F4FDA59AFAC3824" xlink:type="arc"/>
<link:loc xlink:href="pnr-20180331.xsd#pnr_ElectricalFasteningSolutionsMember" xlink:label="loc_pnr_ElectricalFasteningSolutionsMember_526460141588C52969FCDA59AFACDFE7" xlink:type="locator"/>
<link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ProductsAndServicesDomain_3C2B0116C78BDB2D4059DA59AFABCC3C" xlink:to="loc_pnr_ElectricalFasteningSolutionsMember_526460141588C52969FCDA59AFACDFE7" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax" xlink:label="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_E6EA13B794514B9FB3D2DA59AFAC903D" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DisaggregationOfRevenueLineItems_4959F6773EF4F561FE5DDA59AFAC55F8" xlink:to="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_E6EA13B794514B9FB3D2DA59AFAC903D" xlink:type="arc"/>
</link:definitionLink>
<link:definitionLink xlink:role="http://www.pentair.com/role/RevenuePerformanceObligationsDetails" xlink:type="extended">
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionLineItems" xlink:label="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionLineItems_3ECBB68A1A87B1881105D4603D09621D" xlink:type="locator"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionTable" xlink:label="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionTable_FC69C2080E44BF178E2FD4603D088E7C" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionLineItems_3ECBB68A1A87B1881105D4603D09621D" xlink:to="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionTable_FC69C2080E44BF178E2FD4603D088E7C" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_RangeAxis" xlink:label="loc_us-gaap_RangeAxis_86D11CDBFC81DE158107D462EECDB103" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionTable_FC69C2080E44BF178E2FD4603D088E7C" xlink:to="loc_us-gaap_RangeAxis_86D11CDBFC81DE158107D462EECDB103" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_RangeMember" xlink:label="loc_us-gaap_RangeMember_72A730F051A88564E77CD462EECE6275_default" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RangeAxis_86D11CDBFC81DE158107D462EECDB103" xlink:to="loc_us-gaap_RangeMember_72A730F051A88564E77CD462EECE6275_default" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_RangeMember" xlink:label="loc_us-gaap_RangeMember_72A730F051A88564E77CD462EECE6275" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RangeAxis_86D11CDBFC81DE158107D462EECDB103" xlink:to="loc_us-gaap_RangeMember_72A730F051A88564E77CD462EECE6275" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_MinimumMember" xlink:label="loc_us-gaap_MinimumMember_EC02D02E611137F2CD4ED4630C8009CB" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RangeMember_72A730F051A88564E77CD462EECE6275" xlink:to="loc_us-gaap_MinimumMember_EC02D02E611137F2CD4ED4630C8009CB" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_MaximumMember" xlink:label="loc_us-gaap_MaximumMember_260B73AB43FB25FD0AADD4632A5A706A" xlink:type="locator"/>
<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RangeMember_72A730F051A88564E77CD462EECE6275" xlink:to="loc_us-gaap_MaximumMember_260B73AB43FB25FD0AADD4632A5A706A" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionStartDateAxis" xlink:label="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionStartDateAxis_F4C26613BE5181D70454D4603D095F78" xlink:type="locator"/>
<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionTable_FC69C2080E44BF178E2FD4603D088E7C" xlink:to="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionStartDateAxis_F4C26613BE5181D70454D4603D095F78" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_RevenueRemainingPerformanceObligation" xlink:label="loc_us-gaap_RevenueRemainingPerformanceObligation_7EE675168D7571930BFAD46071AFC514" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionLineItems_3ECBB68A1A87B1881105D4603D09621D" xlink:to="loc_us-gaap_RevenueRemainingPerformanceObligation_7EE675168D7571930BFAD46071AFC514" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionPeriod" xlink:label="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionPeriod_1716910187EF5397EE8AD462608117D4" xlink:type="locator"/>
<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionLineItems_3ECBB68A1A87B1881105D4603D09621D" xlink:to="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionPeriod_1716910187EF5397EE8AD462608117D4" xlink:type="arc"/>
</link:definitionLink>
<link:definitionLink xlink:role="http://www.pentair.com/role/RevenueScheduleOfContractAssetsAndLiabilitiesDetails" xlink:type="extended"/>
<link:definitionLink xlink:role="http://www.pentair.com/role/RevenueTables" xlink:type="extended"/>
<link:definitionLink xlink:role="http://www.pentair.com/role/SegmentInformation" xlink:type="extended"/>
<link:definitionLink xlink:role="http://www.pentair.com/role/SegmentInformationFinancialInformationByReportableSegmentDetail" xlink:type="extended">
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_SegmentReportingInformationLineItems" xlink:label="loc_us-gaap_SegmentReportingInformationLineItems_66A45DB3A665672D3E30D43B45E3EA61" xlink:type="locator"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable" xlink:label="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_8B8C9C394FCB52D94152D43B45E2B098" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_66A45DB3A665672D3E30D43B45E3EA61" xlink:to="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_8B8C9C394FCB52D94152D43B45E2B098" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_StatementBusinessSegmentsAxis" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_210EB98A203B6D99B227D43B45E2EF57" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_8B8C9C394FCB52D94152D43B45E2B098" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_210EB98A203B6D99B227D43B45E2EF57" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_SegmentDomain" xlink:label="loc_us-gaap_SegmentDomain_15A28E07490AA380C685D43B45E361A6_default" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_210EB98A203B6D99B227D43B45E2EF57" xlink:to="loc_us-gaap_SegmentDomain_15A28E07490AA380C685D43B45E361A6_default" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_SegmentDomain" xlink:label="loc_us-gaap_SegmentDomain_15A28E07490AA380C685D43B45E361A6" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_210EB98A203B6D99B227D43B45E2EF57" xlink:to="loc_us-gaap_SegmentDomain_15A28E07490AA380C685D43B45E361A6" xlink:type="arc"/>
<link:loc xlink:href="pnr-20180331.xsd#pnr_WaterUnitMember" xlink:label="loc_pnr_WaterUnitMember_5542710D8388EB9CEAEFD43B45E332A4" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_15A28E07490AA380C685D43B45E361A6" xlink:to="loc_pnr_WaterUnitMember_5542710D8388EB9CEAEFD43B45E332A4" xlink:type="arc"/>
<link:loc xlink:href="pnr-20180331.xsd#pnr_ElectricalUnitMember" xlink:label="loc_pnr_ElectricalUnitMember_9D9491AC0A2CB86B2CE7D43B45E3138D" xlink:type="locator"/>
<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_15A28E07490AA380C685D43B45E361A6" xlink:to="loc_pnr_ElectricalUnitMember_9D9491AC0A2CB86B2CE7D43B45E3138D" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_AllOtherSegmentsMember" xlink:label="loc_us-gaap_AllOtherSegmentsMember_EE67C4E6E55DA56B5B28D43B45E38A8C" xlink:type="locator"/>
<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_15A28E07490AA380C685D43B45E361A6" xlink:to="loc_us-gaap_AllOtherSegmentsMember_EE67C4E6E55DA56B5B28D43B45E38A8C" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_OperatingSegmentsMember" xlink:label="loc_us-gaap_OperatingSegmentsMember_3C0094DF3BD1EF73CF32D43B45E37903" xlink:type="locator"/>
<link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_15A28E07490AA380C685D43B45E361A6" xlink:to="loc_us-gaap_OperatingSegmentsMember_3C0094DF3BD1EF73CF32D43B45E37903" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_SalesRevenueNet" xlink:label="loc_us-gaap_SalesRevenueNet_E75AE6B011EBE52CA751D43B45E3778C" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_66A45DB3A665672D3E30D43B45E3EA61" xlink:to="loc_us-gaap_SalesRevenueNet_E75AE6B011EBE52CA751D43B45E3778C" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_OperatingIncomeLoss" xlink:label="loc_us-gaap_OperatingIncomeLoss_680CCA5E1E56D42A9084D43B45E3997A" xlink:type="locator"/>
<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_66A45DB3A665672D3E30D43B45E3EA61" xlink:to="loc_us-gaap_OperatingIncomeLoss_680CCA5E1E56D42A9084D43B45E3997A" xlink:type="arc"/>
</link:definitionLink>
<link:definitionLink xlink:role="http://www.pentair.com/role/SegmentInformationReconciliationOfOperatingProfitLossFromSegmentsToConsolidatedDetails" xlink:type="extended">
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_SegmentReportingReconcilingItemForOperatingProfitLossFromSegmentToConsolidatedLineItems" xlink:label="loc_us-gaap_SegmentReportingReconcilingItemForOperatingProfitLossFromSegmentToConsolidatedLineItems_C4302C1A7620C1FE605CDB6A9DCEECAC" xlink:type="locator"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ReconciliationOfOperatingProfitLossFromSegmentsToConsolidatedTable" xlink:label="loc_us-gaap_ReconciliationOfOperatingProfitLossFromSegmentsToConsolidatedTable_4A0BA738C84440B555D4DB6A9DCE2FC0" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_SegmentReportingReconcilingItemForOperatingProfitLossFromSegmentToConsolidatedLineItems_C4302C1A7620C1FE605CDB6A9DCEECAC" xlink:to="loc_us-gaap_ReconciliationOfOperatingProfitLossFromSegmentsToConsolidatedTable_4A0BA738C84440B555D4DB6A9DCE2FC0" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ConsolidationItemsAxis" xlink:label="loc_us-gaap_ConsolidationItemsAxis_86B0C5F9D45AED85347EDB6A9DCE392E" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ReconciliationOfOperatingProfitLossFromSegmentsToConsolidatedTable_4A0BA738C84440B555D4DB6A9DCE2FC0" xlink:to="loc_us-gaap_ConsolidationItemsAxis_86B0C5F9D45AED85347EDB6A9DCE392E" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ConsolidationItemsDomain" xlink:label="loc_us-gaap_ConsolidationItemsDomain_0F64005335B977FDD272DB6A9DCE262C_default" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ConsolidationItemsAxis_86B0C5F9D45AED85347EDB6A9DCE392E" xlink:to="loc_us-gaap_ConsolidationItemsDomain_0F64005335B977FDD272DB6A9DCE262C_default" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ConsolidationItemsDomain" xlink:label="loc_us-gaap_ConsolidationItemsDomain_0F64005335B977FDD272DB6A9DCE262C" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ConsolidationItemsAxis_86B0C5F9D45AED85347EDB6A9DCE392E" xlink:to="loc_us-gaap_ConsolidationItemsDomain_0F64005335B977FDD272DB6A9DCE262C" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_OperatingSegmentsMember" xlink:label="loc_us-gaap_OperatingSegmentsMember_1D8AE98CA371EA4F2960DB6A9DCED154" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConsolidationItemsDomain_0F64005335B977FDD272DB6A9DCE262C" xlink:to="loc_us-gaap_OperatingSegmentsMember_1D8AE98CA371EA4F2960DB6A9DCED154" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_MaterialReconcilingItemsMember" xlink:label="loc_us-gaap_MaterialReconcilingItemsMember_5FCE06EDF74C939F8CDADB6A9DCED6BB" xlink:type="locator"/>
<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConsolidationItemsDomain_0F64005335B977FDD272DB6A9DCE262C" xlink:to="loc_us-gaap_MaterialReconcilingItemsMember_5FCE06EDF74C939F8CDADB6A9DCED6BB" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_OperatingIncomeLoss" xlink:label="loc_us-gaap_OperatingIncomeLoss_42CACA902D085CFA2663DB6A9DCEDFB5" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingReconcilingItemForOperatingProfitLossFromSegmentToConsolidatedLineItems_C4302C1A7620C1FE605CDB6A9DCEECAC" xlink:to="loc_us-gaap_OperatingIncomeLoss_42CACA902D085CFA2663DB6A9DCEDFB5" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_RestructuringCharges" xlink:label="loc_us-gaap_RestructuringCharges_E8724EE7454E3B5D405CDB6A9DDD2B90" xlink:type="locator"/>
<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingReconcilingItemForOperatingProfitLossFromSegmentToConsolidatedLineItems_C4302C1A7620C1FE605CDB6A9DCEECAC" xlink:to="loc_us-gaap_RestructuringCharges_E8724EE7454E3B5D405CDB6A9DDD2B90" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_AmortizationOfIntangibleAssets" xlink:label="loc_us-gaap_AmortizationOfIntangibleAssets_A6C14D7EE838529A8763DB6A9DDDBF14" xlink:type="locator"/>
<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingReconcilingItemForOperatingProfitLossFromSegmentToConsolidatedLineItems_C4302C1A7620C1FE605CDB6A9DCEECAC" xlink:to="loc_us-gaap_AmortizationOfIntangibleAssets_A6C14D7EE838529A8763DB6A9DDDBF14" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_GainLossOnSaleOfBusiness" xlink:label="loc_us-gaap_GainLossOnSaleOfBusiness_A969FA8A8BE6968994ABDB6A9DDD5DD0" xlink:type="locator"/>
<link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingReconcilingItemForOperatingProfitLossFromSegmentToConsolidatedLineItems_C4302C1A7620C1FE605CDB6A9DCEECAC" xlink:to="loc_us-gaap_GainLossOnSaleOfBusiness_A969FA8A8BE6968994ABDB6A9DDD5DD0" xlink:type="arc"/>
<link:loc xlink:href="pnr-20180331.xsd#pnr_SeparationCostsofProposedSpinOff" xlink:label="loc_pnr_SeparationCostsofProposedSpinOff_6BE79A84286CA75EA5C4DB6A9DDD641C" xlink:type="locator"/>
<link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingReconcilingItemForOperatingProfitLossFromSegmentToConsolidatedLineItems_C4302C1A7620C1FE605CDB6A9DCEECAC" xlink:to="loc_pnr_SeparationCostsofProposedSpinOff_6BE79A84286CA75EA5C4DB6A9DDD641C" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_InterestRevenueExpenseNet" xlink:label="loc_us-gaap_InterestRevenueExpenseNet_9BB2436481A2EDC5A298DB6A9DDD3195" xlink:type="locator"/>
<link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingReconcilingItemForOperatingProfitLossFromSegmentToConsolidatedLineItems_C4302C1A7620C1FE605CDB6A9DCEECAC" xlink:to="loc_us-gaap_InterestRevenueExpenseNet_9BB2436481A2EDC5A298DB6A9DDD3195" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_OtherExpenses" xlink:label="loc_us-gaap_OtherExpenses_4B53E136943343FE3693DB6A9DDD2E46" xlink:type="locator"/>
<link:definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingReconcilingItemForOperatingProfitLossFromSegmentToConsolidatedLineItems_C4302C1A7620C1FE605CDB6A9DCEECAC" xlink:to="loc_us-gaap_OtherExpenses_4B53E136943343FE3693DB6A9DDD2E46" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest" xlink:label="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_7B4A2971BA48CDBB1601DB6A9DDD72F0" xlink:type="locator"/>
<link:definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingReconcilingItemForOperatingProfitLossFromSegmentToConsolidatedLineItems_C4302C1A7620C1FE605CDB6A9DCEECAC" xlink:to="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_7B4A2971BA48CDBB1601DB6A9DDD72F0" xlink:type="arc"/>
</link:definitionLink>
<link:definitionLink xlink:role="http://www.pentair.com/role/SegmentInformationTables" xlink:type="extended"/>
<link:definitionLink xlink:role="http://www.pentair.com/role/SharePlans" xlink:type="extended"/>
<link:definitionLink xlink:role="http://www.pentair.com/role/SharePlansAdditionalInformationDetail" xlink:type="extended">
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_ECE18719F47422E7D832CFF4136B28E3" xlink:type="locator"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" xlink:label="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_B393D8D9723786504F80CFF4136A0272" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_ECE18719F47422E7D832CFF4136B28E3" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_B393D8D9723786504F80CFF4136A0272" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_AwardTypeAxis" xlink:label="loc_us-gaap_AwardTypeAxis_8E90971C0D4402837398CFF4136A68A9" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_B393D8D9723786504F80CFF4136A0272" xlink:to="loc_us-gaap_AwardTypeAxis_8E90971C0D4402837398CFF4136A68A9" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_06C1F5966F5CAACB5C4DCFF4136A6CC1_default" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AwardTypeAxis_8E90971C0D4402837398CFF4136A68A9" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_06C1F5966F5CAACB5C4DCFF4136A6CC1_default" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_06C1F5966F5CAACB5C4DCFF4136A6CC1" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AwardTypeAxis_8E90971C0D4402837398CFF4136A68A9" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_06C1F5966F5CAACB5C4DCFF4136A6CC1" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_RestrictedStockUnitsRSUMember" xlink:label="loc_us-gaap_RestrictedStockUnitsRSUMember_6D13E649D52C42F80A49CFF4136A6D36" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_06C1F5966F5CAACB5C4DCFF4136A6CC1" xlink:to="loc_us-gaap_RestrictedStockUnitsRSUMember_6D13E649D52C42F80A49CFF4136A6D36" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_StockOptionMember" xlink:label="loc_us-gaap_StockOptionMember_2F150FD4B08B56853CD4CFF4136BFDC1" xlink:type="locator"/>
<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_06C1F5966F5CAACB5C4DCFF4136A6CC1" xlink:to="loc_us-gaap_StockOptionMember_2F150FD4B08B56853CD4CFF4136BFDC1" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_PerformanceSharesMember" xlink:label="loc_us-gaap_PerformanceSharesMember_3B8AA7E3CAE4973FACC6CFF4136B9503" xlink:type="locator"/>
<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_06C1F5966F5CAACB5C4DCFF4136A6CC1" xlink:to="loc_us-gaap_PerformanceSharesMember_3B8AA7E3CAE4973FACC6CFF4136B9503" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ShareBasedCompensation" xlink:label="loc_us-gaap_ShareBasedCompensation_36249F07BF0E1D671B6ECFF4136BF65B" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_ECE18719F47422E7D832CFF4136B28E3" xlink:to="loc_us-gaap_ShareBasedCompensation_36249F07BF0E1D671B6ECFF4136BF65B" xlink:type="arc"/>
</link:definitionLink>
<link:definitionLink xlink:role="http://www.pentair.com/role/SharePlansTables" xlink:type="extended"/>
<link:definitionLink xlink:role="http://www.pentair.com/role/ShareholdersEquity" xlink:type="extended">
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_StatementLineItems" xlink:label="loc_us-gaap_StatementLineItems_0EF740D0BAA553549BDD6BC36A54AA48" xlink:type="locator"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_StatementTable" xlink:label="loc_us-gaap_StatementTable_F576094EA6155909B76D4BAC3EC6F738" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_0EF740D0BAA553549BDD6BC36A54AA48" xlink:to="loc_us-gaap_StatementTable_F576094EA6155909B76D4BAC3EC6F738" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment"/>
<link:loc xlink:href="http://xbrl.sec.gov/dei/2014/dei-2014-01-31.xsd#dei_LegalEntityAxis" xlink:label="loc_dei_LegalEntityAxis_1143E96C10F95064AFF2D9EE62739324" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_F576094EA6155909B76D4BAC3EC6F738" xlink:to="loc_dei_LegalEntityAxis_1143E96C10F95064AFF2D9EE62739324" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.sec.gov/dei/2014/dei-2014-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_66197E4F6F015E4B340457C26FCB7A98_E3B43B43A3E7574E8DA0F8529D4EC1C5" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_1143E96C10F95064AFF2D9EE62739324" xlink:to="loc_dei_EntityDomain_66197E4F6F015E4B340457C26FCB7A98_E3B43B43A3E7574E8DA0F8529D4EC1C5" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.sec.gov/dei/2014/dei-2014-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_128D45064E745C77AAE626A57CB766B0" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_1143E96C10F95064AFF2D9EE62739324" xlink:to="loc_dei_EntityDomain_128D45064E745C77AAE626A57CB766B0" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_StockholdersEquityNoteDisclosureTextBlock" xlink:label="loc_us-gaap_StockholdersEquityNoteDisclosureTextBlock_D13339B5DDB15F83A1B790E1BC3ABF3A" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_0EF740D0BAA553549BDD6BC36A54AA48" xlink:to="loc_us-gaap_StockholdersEquityNoteDisclosureTextBlock_D13339B5DDB15F83A1B790E1BC3ABF3A" xlink:type="arc"/>
</link:definitionLink>
<link:definitionLink xlink:role="http://www.pentair.com/role/ShareholdersEquityAdditionalInformationDetail" xlink:type="extended">
<link:loc xlink:href="pnr-20180331.xsd#pnr_StockholdersEquityNoteDisclosureLineItems" xlink:label="loc_pnr_StockholdersEquityNoteDisclosureLineItems_C47A5104DF75376543B6CFF412278022" xlink:type="locator"/>
<link:loc xlink:href="pnr-20180331.xsd#pnr_StockholdersEquityNoteDisclosureTable" xlink:label="loc_pnr_StockholdersEquityNoteDisclosureTable_BC311B86E0885C7F8D39CFF41226270C" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_pnr_StockholdersEquityNoteDisclosureLineItems_C47A5104DF75376543B6CFF412278022" xlink:to="loc_pnr_StockholdersEquityNoteDisclosureTable_BC311B86E0885C7F8D39CFF41226270C" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ShareRepurchaseProgramAxis" xlink:label="loc_us-gaap_ShareRepurchaseProgramAxis_63E2BDC880C9593F3EB8CFF412270D75" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_pnr_StockholdersEquityNoteDisclosureTable_BC311B86E0885C7F8D39CFF41226270C" xlink:to="loc_us-gaap_ShareRepurchaseProgramAxis_63E2BDC880C9593F3EB8CFF412270D75" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ShareRepurchaseProgramDomain" xlink:label="loc_us-gaap_ShareRepurchaseProgramDomain_FE7B8239381BFEE47F3ACFF4122713DA_default" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ShareRepurchaseProgramAxis_63E2BDC880C9593F3EB8CFF412270D75" xlink:to="loc_us-gaap_ShareRepurchaseProgramDomain_FE7B8239381BFEE47F3ACFF4122713DA_default" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ShareRepurchaseProgramDomain" xlink:label="loc_us-gaap_ShareRepurchaseProgramDomain_FE7B8239381BFEE47F3ACFF4122713DA" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ShareRepurchaseProgramAxis_63E2BDC880C9593F3EB8CFF412270D75" xlink:to="loc_us-gaap_ShareRepurchaseProgramDomain_FE7B8239381BFEE47F3ACFF4122713DA" xlink:type="arc"/>
<link:loc xlink:href="pnr-20180331.xsd#pnr_December2014ShareRepurchaseProgramMember" xlink:label="loc_pnr_December2014ShareRepurchaseProgramMember_1222C7B77B842B737B6BCFF412273C44" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareRepurchaseProgramDomain_FE7B8239381BFEE47F3ACFF4122713DA" xlink:to="loc_pnr_December2014ShareRepurchaseProgramMember_1222C7B77B842B737B6BCFF412273C44" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_StockRepurchaseProgramAuthorizedAmount1" xlink:label="loc_us-gaap_StockRepurchaseProgramAuthorizedAmount1_32FCF749B4890DE0B736CFF4122704F3" xlink:type="locator"/>
<link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_pnr_StockholdersEquityNoteDisclosureLineItems_C47A5104DF75376543B6CFF412278022" xlink:to="loc_us-gaap_StockRepurchaseProgramAuthorizedAmount1_32FCF749B4890DE0B736CFF4122704F3" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_StockRepurchaseProgramExpirationDate" xlink:label="loc_us-gaap_StockRepurchaseProgramExpirationDate_D7BBF740D5795811AEBFCFF4122723D4" xlink:type="locator"/>
<link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_pnr_StockholdersEquityNoteDisclosureLineItems_C47A5104DF75376543B6CFF412278022" xlink:to="loc_us-gaap_StockRepurchaseProgramExpirationDate_D7BBF740D5795811AEBFCFF4122723D4" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_StockRepurchaseProgramRemainingAuthorizedRepurchaseAmount1" xlink:label="loc_us-gaap_StockRepurchaseProgramRemainingAuthorizedRepurchaseAmount1_41C91434CF32EAB0D736CFF412281D5F" xlink:type="locator"/>
<link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_pnr_StockholdersEquityNoteDisclosureLineItems_C47A5104DF75376543B6CFF412278022" xlink:to="loc_us-gaap_StockRepurchaseProgramRemainingAuthorizedRepurchaseAmount1_41C91434CF32EAB0D736CFF412281D5F" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DividendsPayableAmountPerShare" xlink:label="loc_us-gaap_DividendsPayableAmountPerShare_CFB7D30C9A98301F693FCFF4122801CA" xlink:type="locator"/>
<link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_pnr_StockholdersEquityNoteDisclosureLineItems_C47A5104DF75376543B6CFF412278022" xlink:to="loc_us-gaap_DividendsPayableAmountPerShare_CFB7D30C9A98301F693FCFF4122801CA" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_TreasuryStockSharesAcquired" xlink:label="loc_us-gaap_TreasuryStockSharesAcquired_C5559344EC655523D737CFF41228E723" xlink:type="locator"/>
<link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_pnr_StockholdersEquityNoteDisclosureLineItems_C47A5104DF75376543B6CFF412278022" xlink:to="loc_us-gaap_TreasuryStockSharesAcquired_C5559344EC655523D737CFF41228E723" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_StockRepurchasedDuringPeriodValue" xlink:label="loc_us-gaap_StockRepurchasedDuringPeriodValue_408E343AF74C5767781BCFF41228D1B7" xlink:type="locator"/>
<link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_pnr_StockholdersEquityNoteDisclosureLineItems_C47A5104DF75376543B6CFF412278022" xlink:to="loc_us-gaap_StockRepurchasedDuringPeriodValue_408E343AF74C5767781BCFF41228D1B7" xlink:type="arc"/>
<link:loc xlink:href="pnr-20180331.xsd#pnr_ApprovedNotDeclaredlDividends" xlink:label="loc_pnr_ApprovedNotDeclaredlDividends_1173DE177ED3B773BEAACFF412288DB6" xlink:type="locator"/>
<link:definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_pnr_StockholdersEquityNoteDisclosureLineItems_C47A5104DF75376543B6CFF412278022" xlink:to="loc_pnr_ApprovedNotDeclaredlDividends_1173DE177ED3B773BEAACFF412288DB6" xlink:type="arc"/>
<link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DividendsPayableCurrent" xlink:label="loc_us-gaap_DividendsPayableCurrent_1D75429D41CF6049D9EECFF41228B8EB" xlink:type="locator"/>
<link:definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_pnr_StockholdersEquityNoteDisclosureLineItems_C47A5104DF75376543B6CFF412278022" xlink:to="loc_us-gaap_DividendsPayableCurrent_1D75429D41CF6049D9EECFF41228B8EB" xlink:type="arc"/>
</link:definitionLink>
<link:definitionLink xlink:role="http://www.pentair.com/role/SupplementalBalanceSheetInformation" xlink:type="extended"/>
<link:definitionLink xlink:role="http://www.pentair.com/role/SupplementalBalanceSheetInformationDetail" xlink:type="extended"/>
<link:definitionLink xlink:role="http://www.pentair.com/role/SupplementalBalanceSheetInformationTables" xlink:type="extended"/>
</link:linkbase>


4 Subsequent Filings that Reference this Filing

  As Of               Filer                 Filing    For·On·As Docs:Size             Issuer                      Filing Agent

 2/20/24  Pentair plc                       10-K       12/31/23  127:14M
 2/21/23  Pentair plc                       10-K       12/31/22  123:44M
 2/22/22  Pentair plc                       10-K       12/31/21  120:13M
 2/16/21  Pentair plc                       10-K       12/31/20  128:14M
Top
Filing Submission 0000077360-18-000016   –   Alternative Formats (Word / Rich Text, HTML, Plain Text, et al.)

Copyright © 2024 Fran Finnegan & Company LLC – All Rights Reserved.
AboutPrivacyRedactionsHelp — Fri., May 17, 4:40:18.2pm ET