BS4255--1-Gasket

BRITISHSTANDARDBS4255-1:1986Rubberusedinpreformedgasketsforweatherexclusionfrombuildings—Part1:Specificationfornon-cellulargasketsUDC678.074:[62–762.4:699.83]Licensedcopy:BUJArchitects,26/05/2004,UncontrolledCopy,©BSIBS4255-1:1986ThisBritishStandard,havingbeenpreparedunderthedirectionoftheRubberStandardsCommittee,waspublishedundertheauthorityoftheBoardofBSIandcomesintoeffecton30May1986©BSI07-1999FirstpublishedDecember1967FirstrevisionMay1986ThefollowingBSIreferencesrelatetotheworkonthisstandard:CommitteereferenceRUM/35Draftforcomment83/37993DCISBN0580150771CommitteesresponsibleforthisBritishStandardThepreparationofthisBritishStandardwasentrustedbytheRubberStandardsCommittee(RUM/-)toTechnicalCommitteeRUM/35,uponwhichthefollowingbodieswererepresented:BritishRubberManufacturers’AssociationBritishStructuralBearingsManufacturers’AssociationBuildingEmployers’ConfederationConcreteSocietyDepartmentoftheEnvironment(BuildingResearchEstablishment,PrincesRisboroughLaboratory)DepartmentofTransport(Highways)FlexibleRoofingAssociationInstituteofMedicalLaboratorySciencesInstitutionofStructuralEngineersMalaysianRubberProducers’ResearchAssociationMinistryofDefenceRoyalSocietyofChemistryAmendmentsissuedsincepublicationAmd.No.DateofissueCommentsLicensedcopy:BUJArchitects,26/05/2004,UncontrolledCopy,©BSIBS4255-1:1986©BSI07-1999iContentsPageCommitteesresponsibleInsidefrontcoverForewordii1Scope12Classification13Testing14Generalrequirements15Requirementsforblackandnon-blackrubbergaskets26Marking2Table1—Hardnessclassification1Table2—Requirementsforblackrubbergaskets2Table3—Requirementsforsiliconerubberandwhiteandcolouredgaskets2PublicationsreferredtoInsidebackcoverLicensedcopy:BUJArchitects,26/05/2004,UncontrolledCopy,©BSIBS4255-1:1986ii©BSI07-1999ForewordThisPartofBS4255hasbeenpreparedunderthedirectionoftheRubberStandardsCommittee.Itisarevisionofthe1967editionwhichiswithdrawn.Themajorchangesincorporatedinthisrevisionareasfollows:a)chlorosulphonatedpolyethyleneandsiliconerubbershavebeenincludedinthefieldofapplication;b)theclassificationofrubbersbyhardnessandapplicationhasbeenmodified;c)variouschangeshavebeenintroducedintothevaluesspecifiedforthephysicalpropertyrequirements.TherequirementsofISO3934andISO5892,publishedbytheInternationalOrganizationforStandardization(ISO),weretakenintoaccountduringthepreparationofthisPartofBS4255,butthestandardissubstantiallydifferentfromthosetwodocuments.Thisstandardisamaterialspecificationanddoesnotcoverthedesignofgasketsnortheirapplicationtobuildingconstructionnortheirperformanceinservice.Attentionisdrawn,however,tothefollowingstandards.BS4315,Methodsoftestforresistancetoairandwaterpenetration—Part1:Windowsandstructuralgasketglazingsystems.BS6093,Codeofpracticefordesignofjointsandjointinginbuildingconstruction.BS6262,Codeofpracticeforglazingforbuildings.AttentionisalsodrawntoBS3734whichspecifiesdimensionaltolerancesforrubberproducts.Theappropriateclassesoftoleranceforgasketsshouldbeagreedbetweentheuserandthemanufacturer.AtestforthedeterminationofozoneresistanceaftersimulatedageingandleachingistobedevelopedanditishopedthatarequirementforthispropertywilleventuallybeincludedinthisPart.ABritishStandarddoesnotpurporttoincludeallthenecessaryprovisionsofacontract.UsersofBritishStandardsareresponsiblefortheircorrectapplication.CompliancewithaBritishStandarddoesnotofitselfconferimmunityfromlegalobligations.SummaryofpagesThisdocumentcomprisesafrontcover,aninsidefrontcover,pagesiandii,pages1and2,aninsidebackcoverandabackcover.Thisstandardhasbeenupdated(seecopyrightdate)andmayhavehadamendmentsincorporated.Thiswillbeindicatedintheamendmenttableontheinsidefrontcover.Licensedcopy:BUJArchitects,26/05/2004,UncontrolledCopy,©BSIBS4255-1:1986©BSI07-199911ScopeThisPartofBS4255specifiesrequirementsfortheclassification,physicalpropertiesandmarkingofsolid(non-cellular)rubberusedinpreformedgasketsforsealingapplicationsinbuildingswhereresistancetoweathering,ozoneandpermanentdeformationunderloadareofprimeimportance.ThisPartappliestochloroprene,butyl,halobutyl,ethylenepropylene,chlorosulphonatedpolyethyleneandsiliconerubbersusedinthegaskets.Fiveclassesofmaterial,definedaccordingtothehardnessoftherubber,arespecified.NOTEThetitlesofthepublicationsreferredtointhisPartofBS4255arelistedontheinsidebackcover.2ClassificationTherubbershallbeclassifiedaccordingtoitshardness,asgiveninTable1.ThehardnessshallbedeterminedinaccordancewiththeappropriatemethodinBS903-A26.MethodMshallbeusedforsmallcomponents;otherwisemethodNormethodHshallbeused,accordingtotheexpectedhardnessvalue.Table1—Hardnessclassification3TestingTestsshallnormallybecarriedoutontestpiecestakenfromtheactualgasket.Butifthegasketistoonarrowforaparticulartestpiecetobecutfromit,thattestshallbecarriedoutusingtestpiecestakenfromaspeciallymouldedsheet,vulcanizedunderconditionswhichshallachievethesamestateofcureasthatoftheactualgasket;thisshallbereportedinthedocumentationthataccompaniesthegasketssuppliedtothepurchaser.4Generalrequirements4.1AppearanceandfinishWhenexaminedvisually,a