BS 2779-1986 Specification for Pipe threads for tu

BRITISHSTANDARDBS2779:1986SpecificationforPipethreadsfortubesandfittingswherepressure-tightjointsarenotmadeonthethreads(metricdimensions)UDC621.643.414:621.882.082.1LicensedCopy:AUBUser,na,SunMar2513:38:08GMT+00:002007,UncontrolledCopy,(c)BSIBS2779:1986ThisBritishStandard,havingbeenpreparedunderthedirectionofthePipingSystemsComponentsStandardsCommittee,waspublishedundertheauthorityoftheBoardofBSIandcomesintoeffecton29August1986©BSI12-1998FirstpublishedDecember1956FirstrevisionApril1973SecondrevisionAugust1986ThefollowingBSIreferencesrelatetotheworkonthisstandard:CommitteereferencePSE/9Draftforcomment85/75381DCISBN058015212XCommitteesresponsibleforthisBritishStandardThisBritishStandardwasentrustedbythePipingSystemsComponentsStandardsCommittee(PSE/-)toTechnicalCommitteePSE/9,uponwhichthefollowingbodieswererepresented:AssociationofHydraulicEquipmentManufacturersBritishCompressedAirSocietyBritishEngineGroupoftheSocietyofMotorManufacturersandTradersBritishGasCorporationBritishHydromechanicsResearchAssociationBritishMalleableTubeFittingsAssociationBritishSteelIndustryBritishValveManufacturersAssociationLtd.CopperTubeFittingsManufacturers’AssociationDepartmentofTradeandIndustry(NationalEngineeringLaboratory)EnergyIndustriesCouncilEngineeringEquipmentandMaterialsUsers’AssociationGaugeandToolMakers’AssociationInstitutionofCivilEngineersInstitutionofGasEngineersInstitutionofPublicHealthEngineersInstitutionofWaterEngineersandScientistsWaterAuthoritiesAssociationWaterCompaniesAssociationWroughtFittingMakers’AssociationAmendmentsissuedsincepublicationAmd.No.DateofissueCommentsLicensedCopy:AUBUser,na,SunMar2513:38:08GMT+00:002007,UncontrolledCopy,(c)BSIBS2779:1986©BSI12-1998iContentsPageCommitteesresponsibleInsidefrontcoverForewordii1Scope12Symbols13Classificationanddesignation14Threaddetails4AppendixASpecialtruncatedformoftheWhitworththreadforclassAexternalthreads5AppendixBNotesontolerancingsystemstructure5AppendixCMethodofverificationofthreadsizeandformbymeansoflimitgauges6AppendixDGaugesforthemethodgiveninappendixC8Figure1—Threadprofileandtolerancezones4Figure2—Specialtruncatedexternalthread5Figure3—NOTGOscrewcallipergauge7Figure4—Startofcompletethread8Figure5—Chamferofstartofthread8Figure6—ThreadprofilesofGOringgaugesandtheircheckplugs9Figure7—RelativepositionsofpitchdiametertolerancezonesforGOringgaugesandtheircheckplugs10Figure8—ThreadprofilesofNOTGOringgaugesandtheircheckplugsandcallipergauges11Figure9—RelativepositionsofpitchdiametertolerancezonesforNOTGOringgauges,callipergaugesandtheircheckplugs12Figure10—ThreadprofilesofGoandNOTGOpluggauges13Figure11—RelativepositionsofpitchdiametertolerancezonesforGOandNOTGOpluggauges14Table1—Basicdimensionsandtolerances3Table2—Specialtruncatedfasteningthreads,classAexternalthreads5Table3—DimensionsforGOandNOTGOgaugesandtheircheckplugsforclassAexternalthreadsandforGOgaugesandtheircheckplugsforclassBexternalthreads9Table4—OthervaluesforGOandNOTGOgaugesandtheircheckplugsforclassAandclassBexternalthreadsasafunctionofthepitch,P10Table5—DimensionsforNOTGOgaugesandtheircheckplugsforclassBexternalthreads11Table6—DimensionsforthreadedGOandNOTGOpluggauges13Table7—OthervaluesforGOandNOTGOpluggaugesasafunctionofthepitch,P14PublicationsreferredtoInsidebackcoverLicensedCopy:AUBUser,na,SunMar2513:38:08GMT+00:002007,UncontrolledCopy,(c)BSIBS2779:1986ii©BSI12-1998ForewordThisrevisionofBS2779hasbeenpreparedunderthedirectionofthePipingSystemsComponentsStandardsCommittee.ItsupersedesBS2779:1973,whichiswithdrawn.ThisstandardisbasedonandistechnicallyequivalenttothetwoPartsofISO228“Pipethreadswherepressure-tightjointsarenotmadeonthethreads”,namelyISO228/1-1982“Designation,dimensionsandtolerances”,andISO/2-1980“Verificationbymeansoflimitgauges”;bothPartsarepublishedbytheInternationalOrganizationforStandardization(ISO).Thisstandardprovidesarangeofthreadsizeswhichareconsideredtobenecessarytofulfilgeneralrequirements.Dimensionsaregiveninmetricunitsonly.Foreaseofproduction,ithasbeenfoundconvenienttoreproducethefiguresfromISO228/2-1980forFigure4,Figure5,Figure7,Figure10andFigure11ofthisstandard.ABritishStandarddoesnotpurporttoincludeallthenecessaryprovisionsofacontract.UsersofBritishStandardsareresponsiblefortheircorrectapplication.CompliancewithaBritishStandarddoesnotofitselfconferimmunityfromlegalobligations.SummaryofpagesThisdocumentcomprisesafrontcover,aninsidefrontcoverpagesiandii,pages1to14,aninsidebackcoverandabackcover.Thisstanderdhasbeenupdated(seecopyrightdate)andmayhavehadamendmentsincorporated.Thiswillbeindicatedintheamendmenttableontheinsidefrontcover.LicensedCopy:AUBUser,na,SunMar2513:38:08GMT+00:002007,UncontrolledCopy,(c)BSIBS2779:1986©BSI12-199811ScopeThisBritishStandardspecifiesrequirementsforthedesignationanddimensionsofWhitworthformfasteningpipethreadshavingathreadsizedesignationintherange1/16to6inclusive.Thisstandardappliestopipethreadswherepressure-tightjointsarenotmadeonthethreads1).Dimensionsaregiveninmetricunits.Thetoleranceonthecrestsofthethreadsallowsfortruncation(see4.1).NOTE