Designation:D7211−13StandardSpecificationforPartsMachinedfromPolychlorotrifluoroethylene(PCTFE)andIntendedforGeneralUse1ThisstandardisissuedunderthefixeddesignationD7211;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.1.Scope*1.1Thisspecificationisintendedtobeameansofcallingoutfinishedmachinedpartsreadyforcommercialuse.1.2Thisspecificationestablishesrequirementsforpartsmachinedfromunplasticized,100%polychlorotrifluoroethyl-ene(PCTFE)homopolymers.1.3ThisspecificationdoesnotcoverpartsmachinedfromPCTFEcopolymers,PCTFEfilmortapelessthan0.25-mm(0.010-in.)thick,ormodifiedPCTFE(containingpigmentsorplasticizers).1.4Thisspecificationallowsforpartscontainingregrindandrecycledmaterial.1.5ThespecificationdoesnotcoverPCTFEpartsusedinaerospaceapplicationsinvolvingstorageandhandlingofoxygenmedia,airmedia,inertmedia,andcertainreactivemedia(specificallyammonia,gaseoushydrogen,andliquidhydrogen),inwhichdimensionalstability,highmolecularweight,molecularweightretention,andcrystallinitycontrolareimportantconsiderations.Foraerospacegrade,machinedPCTFEparts,useSpecificationD7194.1.6Application—PCTFEpartscoveredbythisspecificationaremadeof100%PCTFEresin,freeofplasticizers,fillers,orotheradditives.Thepartsmeetspecificphysicalcharacteristicsappropriatefortheirenduse,andaretypicallyusedinapplicationsrequiringgoodelectricalpropertiesorresistancetoaggressivechemicalmedia.GeneralpurposePCTFEpartsincludeseals,gaskets,valveandpumpparts(cryogenicandnoncryogenic),translucenttubing,sightglasses,flowmetertubes,heavy-walledsolidpipesandfittings,gears,cams,bearings,laboratoryware,circuitboards,electricalconnectorcoversandswitches,radomecovers,andavarietyofotherstockshapes.Theyareremovedandreplacedduringnormalmaintenanceprocedures.Thepartsalsoexperiencestaticordynamicmechanicalloading,andtemper...
