GUIDE FORPVC PRESSURE FITTINGS

PVC PRESSURE FITTINGSTABLE OF CONTENTS

Introduction 3

StandardsandSpecifications 3

Products 4

Manufacturing Methods 8

FabricatedFittings 8

Injection-MoldedFittings 9

MachinedCouplings 9

CompatibilitywithDissimilarMaterials 9

Designing to Prevent Pipe Movement 10

InternallyRestrainedJoints 11

ExternalRestraintDevices 12

ConcreteThrustBlocks 13

Installation 13

Handling 13

PipeandFittingPreparation 13

JointAssembly 13

ChangesinDirection 14

AcceptanceTesting 14

MemberCompanyFittingsManufacturers 15

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PVC PRESSURE FITTINGSINTRODUCTION

ThisdocumenthasbeendevelopedbytheUni-BellPVCPipeAssociationfordesignandinstallationofgasketedPVCfittingswheregasketedPVCpressurepipeisusedinpotablewater,forcemain,pressureirrigation,andreclaimedwaterapplications.TheguideprovidesinformationongasketedPVCfittingsthatareavailableforvariousdimensionratiosandoutsidediametersofPVCpipethrough60-inch.ThisdocumentdoesnotincludeinformationonsolventweldedorfusiblePVCfittings.

STANDARDS AND SPECIFICATIONSProductstandardsusedinthisguideinclude:

• ASTMD2774,StandardPracticeforUndergroundInstallationofThermoplasticPressurePiping

• ASTMD3139,StandardSpecificationforJointsforPlasticPressurePipesUsingFlexibleElastomericSeals

• ASTMF477,StandardSpecificationforElastomericSeals(Gaskets)forJoiningPlasticPipe

• ASTMF1674,TestMethodforJointRestraintProductsforUsewithPVCPipe

• AWWAC605,UndergroundInstallationofPolyvinylChloride(PVC)andMolecularlyOrientedPolyvinylChloride(PVCO)PressurePipeandFittings

• AWWAC900,PolyvinylChloride(PVC)PressurePipeandFabricatedFittings,4-inchthrough60-inch(100mmthrough1500mm)

Note:In2016,AWWA’slatesteditionofC900consolidatedalldiameters4-inchthrough60-inchintoasinglestandard;therefore,allfabricatedfittingsandmachinedcouplingscannowbespecifiedbyreferencingtheC900standard.

• AWWAC907,Injection-MoldedPolyvinylChloride(PVC)PressureFittings,4-inchthrough12-inch(100mmthrough300mm),forWater,Wastewater,andReclaimedWaterService

• CSAB137.2,PVCInjection-MouldedGasketedFittingsforPressureApplications

• CSAB137.3,RigidPolyvinylChloride(PVC)PipeforPressureApplications

• FM1612,PolyvinylChloride(PVC)PipeandFittingsForUndergroundFireProtectionService

• NSF/ANSI14,PlasticsPipingSystemComponentsandRelatedMaterials

• NSF/ANSI61,DrinkingWaterSystemComponents–HealthEffects

• UL1285,StandardforPipeandCouplings,PolyvinylChloride(PVC),andOrientedPolyvinylChloride(PVCO)forUndergroundFireService

GUIDEFORPVCPRESSUREFITTINGS3

PVC PRESSURE FITTINGSPRODUCTSThedifferenttypesoffittingsareasfollows:

Teeshaveanoutstandinglegthatis90°fromthemain.

Crosseshavetwooutstandinglegsthatareoppositeeachother.

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PVC PRESSURE FITTINGSPRODUCTS (CONT.)

Bends can havestandardangles(11.25°,22.5°,45°and90°)oranycustom-builtanglefrom1°to90°.

Sweeps areusedtochangealignment/directionwhilereducinghydrauliclosses.Sweepsaretypicallyavailablefrom1°to5°.

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PVC PRESSURE FITTINGSPRODUCTS (CONT.)

Couplings/Sleevesareusedtojointwopipesthathavethesamediameter.Thesehavemultipleapplicationsincluding:

• Tie-inconnectionstoexistinglines

• Connectingshortlengthsofpipe

• Repairingdamagedpipelines

• Changingpipelinedirection(high-deflectioncoupling)

Reducers/Tapers/Adaptersareusedtotransitionbetweentwodifferentpipediameters.

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PVC PRESSURE FITTINGSPRODUCTS (CONT.)

Tapped Couplingsareone-piecefittingswithpre-moldedthreadsforservicetaps.Tappedcouplingsareavailabletoaccommodatevariousmainlinesizeswithnumeroustapconfigurations.

Plugs/Capsaredesignedforstoppingflowonasegmentofpipe.Plugsareusedatdeadends.

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PVC PRESSURE FITTINGSPRODUCTS (CONT.)

MANUFACTURING METHODSTherearethreemanufacturingmethodsusedforAWWAPVCfittings.Allthreetypesusegasketedpush-onjointsandtheinternalpressurecapacityisequaltoorgreaterthanthatofthepipepressurerating.

FABRICATED FITTINGS

FabricatedfittingsareconstructedfromsectionsofPVCpipemeetingtherequirementsoftheAWWAC900standard.Theirconstituentpartsarethesameasthepipelinewithwhichtheywillbeused.ThebodyofthefittingisextrudedPVCpipethathasalreadypassedthestandard’stestingrequirements.Fabricatedfittingsincludesinglethermoformedbendsandcouplers.Aswell,multiplesegmentsofPVCpipecanbecutintowedgeshapes,orpreparedtoacceptleginsertions,andjoinedunderfactory-controlledconditionstoformanessentiallyhomogeneousstructure.Reinforcementmaybeappliedandpermanentlybondedtotheoutsidesurfacesofthefittings.

Availableproductsinclude:• Tees• Crosses• Bends(standardorcustomangles)• Couplings• Reducers• Adapters• Tapers

Custom Productscanbemanufacturedandareavailableinpush-onorrestrainedjoint.

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PVC PRESSURE FITTINGSFabricatedPVCfittingsareavailableforanysizePVCpipefrom4-inchthrough60-inch.Fabricatedfittingsare availableinmultiplepressureclassesandhavethesameorgreaterpressureclassasthePVCpipetowhichtheyarejoined.PleaseuseAWWAC900forfabricatedfittingsrecommendedspecifications.

INJECTION-MOLDED FITTINGS

Injection-moldedfittingsaremanufacturedbyinjectingPVCcompoundintoamoldcavityperAWWAC907.ThestandardrequiresthateachfittingbemadefromPVCcompoundwithaminimumHydrostaticDesignBasisof4,000psiandashort-termstrengthof6,400psi.Qualificationtestsmustproducealong-termpressurestrengthof470psi.Injection-moldedPVCfittingshaveawallthicknessaminimumof25%thickerthanDR18pipe.

Availableproductsinclude:• Bends(standardorcustomangles)• Couplings• Tees• Reducers• Adapters• Plugs• Tappedcouplings

Injection-moldedfittingsareavailablefrom4-inchto12-inchdiametersinpressureClass235psi.

MACHINED COUPLINGS MachinedcouplingsareconstructedfromsectionsofPVCpipemeetingtherequirementsoftheAWWAC900standard.TheyareproducedfromacombinationofmoldingandfabricatingmethodsandavailableforanysizePVCpipefrom4-inchthrough60-inch.PleasereferenceAWWAC900forfabricatedfittingsrecommendedspecifications.

COMPATIBILITY WITH DISSIMILAR MATERIALSPipesandfittingsmadefromPVCandDuctileIron(DI)usethesameoutsidediameterregimen,meaningthattheoutsidediametersspecifiedinbothproductstandardsareidentical.(Note:CIOD=CastIronOutsideDiameter,whichisthesameascastironpipesize.)PVCfabricatedfittingsandinjection-moldedfittingsareavailableinCIODandIronPipeSize(IPS).

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PVC PRESSURE FITTINGSTransitioningfromaPVCpipeorfittingintoaDIpipeorfittingiseasilyaccomplishedwheninsertingPVCspigotsintoironbells.Inthissituation,acouplingisnotnecessary.IfmakingthistransitionrequiresaDIspigotintoaPVCbell,transitioncouplingsarenecessary.Checkwithamanufacturerifconnectingtootherdiameterregimens.NOTE: Never insert a DI spigot into a PVC bell. ThisisbecauseDIpipeoutsidediametersareheldtotighttolerancesintheinsideofthebellandtheoutsideofthespigot,whiletheoutsideoftheremainderofthebarrelofthepipeisheldtoloosertolerances.Asaresult,theODoffield-cutDIpipesmayvary.TransitioncouplingsprovidewatertightjointsbetweenPVCandDIpipes.Typicalproductsincludesolid-sleevecouplingsormechanical-compressioncouplings.

DESIGNING TO PREVENT PIPE MOVEMENTLongitudinalthrustforcesmaydevelopinapressurizedpipingsystem.Typicaloptionsforbalancinghydrostaticthrustforcesinclude:

• Internallyrestrainedjoints

• Externalmechanicalrestraintdevices

• Concretethrustblocks

Wheninternalorexternalrestraintisused,thepipelinebecomesitsownthrustblock.Byrestrainingcertainjointsatbendsandalongthepipeline,theresultantthrustforceistransferredtothesurroundingsoilbythepipelineitself.Inaproperlydesignedpipelineusingrestrainedjoints,thrustforcesareresistedbythebearingstrengthofthesoilandthefrictionalresistancebetweenthepipeandsoil.

Thrustforcesaredevelopedat:

• Changesinhorizontalandverticaldirectionatfittings(tees,bends,wyes,andcrosses)

• Changesinpipesize(reducers)

• Deadends(plugs,closedvalves,andhydrants)

Sizeandtypeofinternalorexternalrestraintdevicesorthrustblockingdependon:

• Maximumsystempressure(includingfield-testingpressures)

• Pipesize

• Typeoffittingorappurtenance

• Lineprofile(horizontalorverticalbends)

• Bearingstrengthofundisturbedsoil

• Depth of cover

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GUIDEFORPVCPRESSUREFITTINGS11

PVC PRESSURE FITTINGSTheselectionoftheappropriatemethodforprovidingthrustrestraintmustbebasedontheconsiderationofpresentandfutureconditions.Long-rangeconsiderationsshouldinclude:

• Thepredictionoffutureactivitiesaroundthebendsthatmightjeopardizethewatermain,suchasconstructionofotherservices,changesingroundwaterlevels,andchangesingroundelevation.

• Theabilitytocontrolandmonitoractivitiesaroundthebends,especiallythoseoneasementsawayfrom publicsurveillance.

Computerprogramsareavailabletocalculaterequiredrestrainedlengthsandtoguidetheusertosuggestedconfigurations.Clickhereforathrustrestraintcalculationwebsite.

INTERNALLY RESTRAINED JOINTS

ForeachofthePVCpiperestraintproductslistedbelow,designmethodsareavailablefromthemanufacturer.

Spline-Lock Gasketed Joint-Thisjointusesagasketedcouplingorintegralbellwithnylonsplinesthatextendintoalignedgroovesinthecouplingbellandthepipespigot.

Grip-Ring Gasketed Joint-Restraintinternaltothebellisavailableforbell-and-spigotpipeandfabricatedPVCfittings.

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PVC PRESSURE FITTINGS

Pin-and-Groove Gasketed Joint-Agrooveontheoutsideofthepipespigotalignswithholesspacedaroundthepipebell.Pinsaredriventhroughtheholesintothegroovestopreventmovement.

EXTERNAL RESTRAINT DEVICES

Inordertoproperlyrestrainafitting,itisessentialthattheinstallationinstructionsoftherestraint-devicemanufacturerbefollowed.Correctlubrication,bolt-torque,andtighteningpatternarecrucialtomakingaproperjoint.Fortheexternaljointrestraintproductsbelow,designmethodsareavailablefromthemanufacturer.

External Joint Restraint-Thesedevicesclamptothewallofthepipeandtiebacktoamatingcollaronthefittingorpipebell.

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PVC PRESSURE FITTINGSCONCRETE THRUST BLOCKS Onemethodofresistingtheunbalancedforcesinawatermainisconcretethrustblocks.Thedisadvantageofthrustblocksisthattheyrelyontheundisturbedsoilbehindthethrustblock.Theirreliabilitymaybecompromisediffuturediggingoccursnearthethrustblock.Thrustblocksshouldbeshownonthewatermainsystemplansandacautionarynoteaboutdiggingintheareashouldbeonthedrawing.Insomecases,theactualsizeoftheblockwillprohibititsuse.Thisisparticularlytrueinmanyurbanareas.Inpoorsoilconditions,largeandheavythrustblocksmaycausesettlementofthepipe.SeeChapter11oftheHandbook of PVC Pipe Design and Constructionformoreinformation.

INSTALLATIONFittingsshouldbeinstalledperthegeneralrequirementsofAWWAC605andASTMD2774.

HANDLING

Placethepipeandfittingsintothetrenchusingropesandskids,slingsonthebackhoebucket,orbyhand.Donotthrowpipeorfittingsintothetrenchorallowanypartofthepipetomakeanunrestrainedfallontothetrenchbottom.Ensurethattherearenodamagedmaterialsbeforeassemblybegins.

PIPE AND FITTING PREPARATION

Thepipeendshouldbesquareandbeveled.Thebevelshouldbecutatapproximately15°andshouldbeabout¾-inchlong.Removeanyburrsandridgesonthepipe.Measurethefittingbelldepthandmarkthepipewithaninsertionline.Followthefittingmanufacturer’srecommendedinsertiondepth.Notethatfittinginsertiondepthsareoftendifferentfromthefactoryinsertionlinesmarkedonthepipeandthereforeitisimportanttomeasureandfield-marktheinsertionlinetoensureaproperlyassembledjoint.

Cleanalldebrisfromthebellareasofthefitting.Checkthatthegasketisfullyseatedinthegroovewithnoraisedareas.

Lubricatepipeandfittingperthefittingmanufacturer’sinstructions.

JOINT ASSEMBLY

Alignthepipewiththefittingandpushtogetherbyhandorwithprybars(usingwoodblocksbetween the barsandthefittings).Insertuntiltheinsertionlineisevenwiththeedgeofthefittingbell.Properinsertionisimportantbecauseover-insertionistheprimarycauseofleaksinfittings.Donotinstallusingabackhoe.

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PVC PRESSURE FITTINGSCHANGES IN DIRECTION Do notdeflectthepipeinthefittingbellmorethanthefittingmanufacturer’srecommendation.Becarefulthatover-insertionorover-deflectiondoesnotoccurwheninstallingadjoininglengthsofpipe.Pointloadingcausedbyexcessivedeflectioncancreatedistortionandcauseleaksand/orbreakage.Followthefittingmanufacturer’srecommendationsforjoint-deflectionlimits.Followthepipemanufacturer’srecommendationsfor pipe bending.

ACCEPTANCE TESTING

TestPressure:Ahydrostatictestpressureof150%ofthenormaloperatingpressureisgenerallysufficient.Inno caseshouldthetestpressureexceedthedesignpressureclass/ratingforanysystemcomponentincludingpipe,thrustrestraint,valve,fitting,orotherappurtenance.

NOTE: For safety reasons, compressed air or gas should not be used for pressure rating.

GUIDEFORPVCPRESSUREFITTINGS15

PVC PRESSURE FITTINGSMEMBER COMPANY FITTINGS MANUFACTURERS

Forfurtherinformation,pleasecontactaUni-BellPVCPipeAssociationfittingsmanufacturer:

www.napcopipe.com

www.ipexna.com

UNI-PUB-13-19 2.15.2019

UNI-BELL PVC PIPE ASSOCIATION 2711 LBJ Freeway, Suite 1000

Dallas, TX 75234(972) 243-3902

WWW.UNI-BELL.ORG