Designation:C335/C335M−17StandardTestMethodforSteady-StateHeatTransferPropertiesofPipeInsulation1ThisstandardisissuedunderthefixeddesignationC335/C335M;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.ThisstandardhasbeenapprovedforusebyagenciesoftheU.S.DepartmentofDefense.1.Scope1.1Thistestmethodcoversthemeasurementofthesteady-stateheattransferpropertiesofpipeinsulations.Specimentypesincluderigid,flexible,andloosefill;homogeneousandnonhomogeneous;isotropicandnonisotropic;circularornon-circularcrosssection.Measurementofmetallicreflectiveinsulationandmassinsulationswithmetaljacketsorotherelementsofhighaxialconductanceisincluded;however,additionalprecautionsmustbetakenandspecifiedspecialproceduresmustbefollowed.1.2Thetestapparatusforthispurposeisaguarded-endorcalibrated-endpipeapparatus.Theguarded-endapparatusisaprimary(orabsolute)method.Theguarded-endmethodiscomparable,butnotidenticaltoISO8497.1.3ThevaluesstatedineitherSIunitsorinch-poundunitsaretoberegardedseparatelyasstandard.Thevaluesstatedineachsystemmaynotbeexactequivalents;therefore,eachsystemshallbeusedindependentlyoftheother.Combiningvaluesfromthetwosystemsmayresultinnon-conformancewiththestandard.1.4Whenappropriate,orasrequiredbyspecificationsorothertestmethods,thefollowingthermaltransferpropertiesforthespecimencanbecalculatedfromthemeasureddata(see3.2):1.4.1Thepipeinsulationlinealthermalresistanceandconductance,1.4.2Thepipeinsulationlinealthermaltransference,1.4.3Thesurfacearealresistanceandheattransfercoefficient,1.4.4Thethermalresistivityandconductivity,1.4.5Thearealthermalresistanceandconductance,and1.4.6Thearealthermaltransference.NOTE1—Inthistestmethodthepreferredresistance,conductance,andtransferencearethelinealvaluescomputedforaunitlengthofpipe.Thesemustnotbeconfusedwiththecorrespondingarealp...
