【英文标准名称】:StandardTestMethodforPredictingLong-TermThermalResistanceofClosed-CellFoamInsulation
【原文标准名称】:预测闭孔绝缘泡沫的长期热电阻的标准试验方法
【标准号】:ASTMC1303/C1303M-2010
【标准状态】:现行
【国别】:美国
【发布日期】:2010
【实施或试行日期】:
【发布单位】:美国材料与试验协会(US-ASTM)
【起草单位】:C16.30
【标准类型】:(TestMethod)
【标准水平】:()
【中文主题词】:
【英文主题词】:aging;long-termthermalresistance;LTTR;rigidclosed-cellplasticfoams;scalingfactors;thermalinsulation;thermalresistance;time-averagedthermalresistance;Agingresistance;Controlledtestingconditions/environments;Foamed-in-placethermalin
【摘要】:Rigidgas-filledclosed-cellfoaminsulationsincludeallcellularplasticinsulationswhichrelyonablowingagent(orgas),otherthanair,forthermalresistancevalues.Atthetimeofmanufacture,thecellsofthefoamusuallycontaintheirhighestpercentageofblowingagentandthelowestpercentageofatmosphericgases.Astimepasses,therelativeconcentrationsofthesegaseschangedueprimarilytodiffusion.Thisresultsinageneralreductionofthethermalresistanceofthefoamduetoanincreaseinthethermalconductivityoftheresultantcellgasmixture.Thesephenomenaaretypicallyreferredtoasfoamaging.Forsomerigidgas-filledclosed-cellfoaminsulationproductsproducedusingblowingagentgasesthatdiffuseveryrapidlyoutofthefull-thicknessfoamproduct,suchasexpandedpolystyrene,thereisnoneedtoacceleratetheagingprocess.5.1.2Physicalgasdiffusionphenomenaoccurinthreedimensions.Theone-dimensionalformofthediffusionequationsusedinthedevelopmentofthispracticearevalidonlyforplanargeometries,thatis,forspecimensthathaveparallelfacesandwherethethicknessismuchsmallerthanthewidthandmuchsmallerthanthelength.Note28212;PleaseseeAppendixX3foradiscussionofthetheoryofacceleratedagingviathinslicing.Note38212;Theoreticalandexperimentalevaluationsoftheagingofinsulationinradialforms,suchaspipeinsulation,havebeenmade.(6)However,thesepracticeshavenotevolvedtothepointofinclusionintheteststandard.Thechangeinthermalresistanceduetothephenomenadescribedin5.1usuallyoccursoveranextendedperiodoftime.Informationregardingchangesinthethermalresistanceofthesematerialsasafunctionoftimeisrequiredinashorterperiodoftimesothatdecisionsregardingformulations,production,andcomparisonswithothermaterialscanbemade.SpecificationsC578,C591,C1029,C1126andC1289onrigidclosed-cellfoamsmeasurethermalresistanceafterconditioningat23x00B1;1x00B0;C[73x00B1;2x00B0;F]for180x00B1;5daysfromthetimeofmanufactureorat60x00B1;1x00B0;C[140x00B1;2x00B0;F]for90days.Thisconditioningcanbeusedforcomparativepurposes,butisnotsufficienttodescribelong-termthermalresistance.Thisrequirementdemonstratestheimportanceoftheagingphenomenawithinthisclassofproducts.ThePrescriptiveMethodinPartAprovideslong-termthermalresistancevaluesonaconsistentbasisforavarietyofpurposes,includingproductevaluation,specifications,orproductcomparisons.Theconsistentbasisforthesepurposesisprovidedbyaseriesofspecificproceduralconstraints,whicharenotrequiredintheResearchMethoddescribedinPartB.ThevaluesproducedbythePrescriptiveMethodcorrespondtothethermalresistanceatanageoffiveyears,whichcorrespondscloselytotheaveragethermalresistanceovera15-yearservicelife(7,8).Itisrecommendedthatanymaterialstan......MIL-STD-278F (NOTICE 2), MILITARY STANDARD: WELDING AND CASTING (28 AUG 1997) [S/S BY NAVSEA TECH PUB S9074-AR-GIB-010/278]., MIL-STD-278F(SH), dated 26 January 1987, and Change Notice 1, dated7 January 1992, are hereby canceled. Future acquisitions should refer toNAVSEA Technical Publication S9074-AQ-GIB-010/278, 鈥淩equirements forFabrication Welding and Inspection, and Casting Inspection and Repair forMachinery, Piping, and Pressure Vessels鈥? Stock Number 0910LP7314600.(Copies of NAVSEA Technical Publications can be obtained from the NavalInventory Control Point, Building 1, 700 Robbins Avenue, Philadelphia, PA19111-5094.)