Designation:B891−12StandardSpecificationforSeamlessandWeldedTitaniumandTitaniumAlloyCondenserandHeatExchangerTubeswithEnhancedSurfaceforImprovedHeatTransfer1ThisstandardisissuedunderthefixeddesignationB891;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.1.Scope*1.1Thisspecification2coversseamlessandweldedtitaniumandtitaniumalloytubingonwhichatleastpartoftheexternalorinternalsurfacehasbeenenhancedbycoldformingforimprovedheattransfer.Thetubesareusedinsurfacecondensers,evaporators,heatexchangers,coils,andsimilarheattransferapparatusindiametersuptoandincluding1in.(25.4mm).Thebasetubewallthicknessistypicallyatleast0.049in.average,butlightergaugemaybenegotiatedwiththemanufacturer.1.2Tubingpurchasedtothisspecificationwilltypicallybeinsertedthroughclose-fittingholesintubesheets,baffles,orsupportplatesspacedalongthetubelengthsuchasdefinedintheTubularExchangerManufacturer’sAssociation(TEMA)Standard.3Thetubeendswillalsobeexpanded,andmaythenbewelded.TubemayalsobebenttoformU-tubesorbecoiledorotherwiseformed,althoughtightradiimayrequireunen-hancedlengthforthebends.1.3Thevaluesstatedininch-poundunitsaretoberegardedasstandard.ThevaluesgiveninparenthesesaremathematicalconversionstoSIunitsthatareprovidedforinformationonlyandarenotconsideredstandard.1.4Thefollowingprecautionarystatementpertainstothetestmethodportiononly:Section8,9,10andS1ofthisspecification:Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwithitsuse.Itistheresponsibilityoftheuserofthisstandardtoestablishappro-priatesafetyandhealthpracticesanddeterminetheapplica-bilityofregulatorylimitationspriortouse.2.ReferencedDocuments2.1ASTMStandards:4A1047/A1047MTestMethodforPneumaticLeakTestingofTubingB338SpecificationforSeamlessandWeldedTitaniumandTitaniumAlloyTubesforCondensersandHeatExchang-...
