BRITISHSTANDARDBS5433:1976IncorporatingAmendmentNos.1and2SpecificationforUndergroundstopvalvesforwaterservicesUDC696.117:621.646.651CONFIRMEDDECEMBER2007BS5433:1976ThisBritishStandard,havingbeenpreparedunderthedirectionoftheSanitaryAppliancesStandardsCommittee,waspublishedundertheauthorityoftheExecutiveBoardon30November1976©BSI08-1999ThefollowingBSIreferencesrelatetotheworkonthisstandard:CommitteereferenceSEB/2Draftforcomment73/13411DCISBN0580096300CooperatingorganizationsTheSanitaryAppliancesStandardsCommittee,underwhosesupervisionthisBritishStandardwasprepared,consistsofrepresentativesfromthefollowingGovernmentdepartmentsandscientificandindustrialorganizations:BritishBathManufacturers’Association*InstitutionofPublicHealthEngineersBritishPlasticsFederation*MetalSinkManufacturers’AssociationCouncilofBritishCeramicSanitarywareMinistryofDefenceManufacturers*NationalBrassfoundryAssociation*DepartmentoftheEnvironment*NationalFederationofBuilders’andEnvironmentalHealthOfficers’AssociationPlumbers’Merchants*GreaterLondonCouncil*NationalWaterCouncil*InstituteofPlumbing*RoyalInstituteofBritishArchitectsInstitutionofHeatingandVentilatingRoyalInstituteofPublicHealthandHygieneEngineers*RoyalSocietyofHealth*InstitutionofMunicipalEngineers*WaterCompanies’Association*TheGovernmentdepartmentandscientificandindustrialorganizationsmarkedwithanasteriskintheabovelist,togetherwiththefollowing,weredirectlyrepresentedonthecommitteeentrustedwiththepreparationofthisBritishStandard:AssociationofManufacturersofDomesticHeatingandVentilatingContractors’ElectricalAppliancesAssociationBritishGasCorporationInstituteofBritishFoundrymenBritishNon-ferrousMetalsTechnologyInstitutionofGasEngineersCentreInstitutionofWaterEngineersandBritishValveManufacturers’AssociationScientistsCopperBallManufacturers’AssociationNationalAssociationofPlumbing,HeatingCopperDevelopmentAssociationandMechanicalServicesContractorsCopperTubeFittingsManufacturers’SocietyofBritishGasIndustriesAssociationSouthLondonConsortiumDepartmentoftheEnvironment,BuildingThamesWaterAuthority—MetropolitanResearchEstablishmentWaterDivisionDepartmentofPricesandConsumerIndividualexpertsProtectionAmendmentsissuedsincepublicationAmd.No.DateofissueComments3570December19814596September1984IndicatedbyasidelineinthemarginBS5433:1976©BSI08-1999iContentsPageCooperatingorganizationsInsidefrontcoverForewordiiiSection1.General1Scope12References13Definitions14Illustrations15Nominalsize16Marking1Section2.Dimensions,testingandmaterials7Dimensions18Testing19Materials1Section3.Workmanship10Castings311Forgings312Machining313Thicknessofparts3Section4.Designandconstruction14Waterway315Seat416Screwthreads417Headseal418Washerplate419Bodiesandheads520Methodofattachingcrutchorsquarehead521Clearancebetweencrutchandstuffingbox522Jointwashers523Seatwashers524Glandsandglandpackings525Unionconnections526Hexagonalshoulders6Figure1—Undergroundstopvalve3Figure2—Dimensionsofundergroundstopvalvebodies8Figure3—Dimensionsofheadsandglands10Figure4—Squareheads13Figure5—Dimensionsofcrutches,spindles,washersandwasherplates14Figure6—Dimensionsofends,tailpipesandnuts18Table1—Materials2Table2—Headsealfeatures5Table3—Dimensionsofundergroundstopvalvebodies7Table4—Dimensionsofheadsandglands9Table5—Dimensionsofsquareheads,crutches,spindleswashersandwasherplates11Table6—BSWhitworththreads(external)onspindlesforengagementwithheadthreads(internal)limitsandtolerances:freeclass15Table7—BSWhitworththreads(internal)onheadsforengagementwithspindlethreads(external)limitsandtolerances:normalclass15BS5433:1976ii©BSI08-1999PageTable8—BSWhitworthformscrewthreads(external)onheadsforengagementwithbodythreads(internal)limitsandtolerances:mediumclass15Table9—BSWhitworthformscrewthreads(internal)onbodiesforengagementwithheadthreads(external)limitsandtolerances:mediumclass16Table10—BSWhitworthformscrewthreads(external)onglandsforengagementwithstuffingboxthreads(internal)limitsandtolerances:mediumclass16Table11—BSWhitworthformscrewthreads(internal)instuffingboxforengagementwithglandthreads(external)limitsandtolerances:mediumclass16Table12—Parallelspigotandconeendtailpipesforundergroundstopvalves17PublicationsreferredtoInsidebackcoverBS5433:1976©BSI08-1999iiiForewordThisBritishStandardhasbeenpreparedundertheauthorityoftheSanitaryAppliancesStandardsCommittee.TheoriginalideaforaBritishStandardforspecialstopvalvesarosefromaproposalbythethenBritishWaterworksAssociation(nowNationalWaterCouncil)whohadcarriedoutaninvestigationamongtheirmembersintotheuseandbehaviourofvalvesbasedonBS1010:1959whenusedunderground.Experienceoftheexactingconditionsandlackofaccessibilityinsituationswheretheywereinstalledledtotherecommendationforastrongervalvewithspecialdesignfeaturestomatchtheoperatingconditions.Thedimensionsgivenarethoseconsiderednecessarytoensuretheproductionofvalvesofnominalsizeto2suitableforundergroundwaterservices.Itisrecommendedthatthebodyofthevalveandthemetalcomponentsbebasedongunmetalsandbronzesforstrengthandthatattentionbegiventoresistanceagainstdezincifi