BS 7438-1991 Steel and copper alloy wafer check va

BRITISHSTANDARDBS7438:1991SpecificationforSteelandcopperalloywafercheckvalves,singledisk,spring-loadedtypeBS7438:1991ThisBritishStandard,havingbeenpreparedunderthedirectionofthePipingSystemsComponentsStandardsPolicyCommittee,waspublishedundertheauthorityoftheStandardsBoardandcomesintoeffecton31May1991©BSI08-1999ThefollowingBSIreferencesrelatetotheworkonthisstandard:CommitteereferencePSE/7Draftforcomment90/75853DCISBN0580196143CommitteesresponsibleforthisBritishStandardThepreparationofthisBritishStandardwasentrustedbythePipingSystemsComponentsStandardsPolicyCommittee(PSE/-)toTechnicalCommitteePSE/7,uponwhichthefollowingbodieswererepresented:AmalgamatedEngineeringUnionAssociationofBronzeandBrassFoundersAssociationofBuildingComponentManufacturersBritishChemicalEngineeringContractors’AssociationBritishFoundryAssociationBritishGasplcBritishMaritimeTechnologyBritishPlumbingFittingsManufacturers’AssociationBritishValveandActuatorManufacturers’AssociationCharteredInstitutionofBuildingServicesEngineersCopperDevelopmentAssociationDepartmentoftheEnvironment(PropertyServicesAgency)ElectricitySupplyIndustryinUnitedKingdomEnergyIndustriesCouncilEngineeringEquipmentandMaterialsUsers’AssociationGAMBICA(BEAMALtd.)HealthandSafetyExecutiveInstituteofBritishFoundrymenInstitutionofChemicalEngineersInstitutionofGasEngineersInstitutionofMechanicalEngineersInstitutionofWaterandEnvironmentalManagementLiquefiedPetroleumGasIndustryTechnicalAssociation(UK)PipelineIndustriesGuildSocietyofBritishGasIndustriesSocietyofBritishWaterIndustriesWaterCompanies’AssociationWaterServices’AssociationofEnglandandWalesWestMidlandsCBIAmendmentsissuedsincepublicationAmd.No.DateCommentsBS7438:1991©BSI08-1999iContentsPageCommitteesresponsibleInsidefrontcoverForewordiiSection1.General1Scope12Definitions13Type14Nominalsizes15NominalandClasspressuredesignations16Pressure/temperatureratings17Dimensionsandtolerances2Section2.Designandoperation8Design49Operation4Section3.Materials10Optionalrequirements511Bodymaterial512Disk,spring,springretainermaterials513Identificationplates5Section4.Testing14Productionpressuretesting615Testcertificate6Section5.Markingandpackaging16Bodymarkings717Packaging7AppendixAInformationtobesuppliedbythepurchaser8Figure1—TypicalwafercheckvalveforusewithPNflanges2Figure2—TypicalwafercheckvalveforusewithClassdesignatedflanges3Table1—DimensionsandtolerancesofwafercheckvalvesforusewithPNflanges(typeA)2Table2—DimensionsandtolerancesofwafercheckvalvesforusewithClassdesignatedflanges(typeB)3Publication(s)referredtoInsidebackcoverBS7438:1991ii©BSI08-1999ForewordThisBritishStandardhasbeenpreparedunderthedirectionofthePipingSystemsComponentsStandardsPolicyCommitteeandatthetimeofpublicationofthisBritishStandardnocorrespondinginternationalstandardexists.Face-to-facedimensionscomplywithDIN3202andtolerancescomplywithBS5155.BodyoutsidediametersforwafercheckvalvesforusewithClassdesignatedflangesareconsistentwiththedimensionsofcentringringoutsidediametersofTable1ofBS3381:1989andthoseforusewithPNflangesareconsistentwiththedimensionsofcentringringoutsidediametersofTable1ofBS4865-2:1989.Productcertification.UsersofthisBritishStandardareadvisedtoconsiderthedesirabilityofthirdpartycertificationofproductconformitywiththisBritishStandardbasedontestingandcontinuingsurveillance,whichmaybecoupledwithassessmentofasupplier’squalitysystemsagainsttheappropriatePartofBS5750.EnquiriesastotheavailabilityofthirdpartycertificationschemeswillbeforwardedbyBSItotheAssociationofCertificationBodies.Ifathirdpartycertificationschemedoesnotalreadyexist,usersshouldconsiderapproachinganappropriatebodyfromthelistofAssociationmembers.ABritishStandarddoesnotpurporttoincludeallthenecessaryprovisionsofacontract.UsersofBritishStandardsareresponsiblefortheircorrectapplication.CompliancewithaBritishStandarddoesnotofitselfconferimmunityfromlegalobligations.SummaryofpagesThisdocumentcomprisesafrontcover,aninsidefrontcover,pagesiandii,pages1to8,aninsidebackcoverandabackcover.Thisstandardhasbeenupdated(seecopyrightdate)andmayhavehadamendmentsincorporated.Thiswillbeindicatedintheamendmenttableontheinsidefrontcover.BS7438:1991©BSI08-19991Section1.General1ScopeThisBritishStandardspecifiesrequirementsforthepressure/temperatureratings,dimensions,design,materials,testingandmarkingofsteelandcopperalloywafercheckvalves,singledisk,spring-loadedtypeinnominalsizesDN15toDN100.NOTE1Toassistthepurchaser,AppendixAlistsinformationwhichshouldbesuppliedwhenorderingwafercheckvalves.NOTE2Thetitlesofthepublicationsreferredtointhisstandardarelistedontheinsidebackcover.2DefinitionsForthepurposesofthisBritishStandard,thefollowingdefinitionsapply.2.1waferavalveprimarilyintendedforclampingbetweenpipeflangesusingthroughbolting2.2face-to-facedimensionthedistancebetweentwoplanes,perpendiculartothebodyaxislocatedattheextremitiesofthebodyendports2.3nominalsize(DN)anumericaldesignationofsizewhichiscommontoallcomponentsinapipingsystemotherthanthosecomponentsdesignatedbyoutsidediameterorbythreadsize.Itisaconvenientroundnumbe