Product Code:SAE AIR5565
Title:Historical Design Information of Aircraft Landing Gear And Control Actuation Systems
Issuing Committee:A-5 Aerospace Landing Gear Systems Committee
Scope: This information report (AIR) provides historical design information of various aircraft landing gear and control actuation systems that may be useful in the design of future systems for similar applications. It presents the basic characteristics, hardware descriptions, functional schematics, and discussions of the actuation mechanisms, controls, and alternate release systems.
Rationale: This information report (AIR) provides historical design information of various aircraft landing gear and control actuation systems that may be useful in the design of future systems for similar applications. It presents the basic characteristics, hardware descriptions, functional schematics, and discussions of the actuation mechanisms, controls, and alternate release systems.【英文标准名称】:StandardPracticeforFieldLeakTestingofPolyethylene(PE)PressurePipingSystemsUsingGaseousMediaUnderPressure(PneumaticLeakTesting)
【原文标准名称】:使用压力气体介质对聚乙烯(PE)压力管道系统进行现场渗漏试验的标准实施规程(气体渗漏试验)
【标准号】:ASTMF2786-2010
【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】:F17.40
【标准类型】:(Practice)
【标准水平】:()
【中文主题词】:
【英文主题词】:airtest;compressedairtest,pressure;fieldleaktest,;leaktest;polyethylenepipe;pneumaticleaktest
【摘要】:Ifrequiredbytheauthorityhavingjurisdiction,pressurizedgaseousmedialeaktestingmaybeconductedafterinstallationtodiscoverandcorrectleaksorfaultsinanewlyconstructedormodifiedpolyethylenepressurepipingsystembeforeplacingthesysteminservice.Leakageorfaultsusuallyoccuratconnections,joints,andmechanicalsealswheresealingunderpressureisrequired.Safetyisofparamountimportancewhenconductingpressurizedgaseousmedialeaktestsbecausetestingresultsincludenoleaks,leaks,suddenviolentrupture,orcatastrophicfailure.Systemsthatcontainlowerpressureratedornon-pressureratedcomponentsthatcannotbeisolatedorremovedfromexposuretotestpressure,orwheretemporarycapsorclosuresarenotpractical,arenotsuitablefortestinginaccordancewiththispractice.LeakageAllowance8212;Leakageisnotallowedforjointsincludingbutt,socketandsaddlefusion,electrofusion,andrestrainedgas-tightmechanicaljoints.See7.6.Othertypesofjoints,connections,orcomponentshavingsealsinthesystemmayhavealeakageallowance.Contactthejoint,connectionorcomponentmanufacturerforinformation.Poisson-EffectExpansionandContraction8212;Whentestpressureisappliedtoplasticpipingsystemsthathavefullyrestrainedjointssuchasheatfusion,electrofusion,boltedflanges,etc.,reductionofoveralllengthoranincreaseinlongitudinalstressresultsfromdiametricalexpansionofthepipe.Disjoining(pull-out)ofpartiallyrestrainedornon-restrainedconnectionsorjointssuchasbell-and-spigotjointshavinginsufficientresistancetopull-outstressorlengthreductionispossiblewhensuchjointsarein-linewiththetestsection.TopreventPoisson-effectdisjoining,takemeasuressuchasinstallingexternaljointrestraints(diametricalclampsandtie-rods)acrossin-linepartiallyrestrainedornon-restrainedjoints,installingin-linethrustanchorsattheendsoffullyrestrainedpipingsections,orisolatingafullyrestrainedtestsectionfrompipingwithnonrestrainedorpartiallyrestrainedjoints.Note38212;Atensilestressisappliedtoamaterialwillcauseelongationinthedirectionoftheappliedstress,andwillcauseadecreaseindimensionatrightanglestothedirectionoftheappliedstress.TheratioofdecreasetoelongationisthePoissonratio.Undertestpressure,pipingmaterialswillexpandslightlyindiameterandcontractinlengthslightlyaccordingtothePoissonratioofthematerial.1.1Thispracticeprovidesinformationonapparatus,safety,pre-testpreparationandproceduresforconductingfieldtestsofpolyethylenepressurepipingsystemsafterinstallationusinggaseousmediasuchasunodorizedinertnon-toxicgasorair,andapplyingpressuretodetermineifleaksexistinthesystem(pneumaticleaktesting).Thispracticeappliesonlytotestingtodiscoverleakage.Testingforotherpurposessuchastestingtoestablishoperatingpressureisbeyondthescopeofthispractice.1.2Thispracticedoesnotaddressleaktestingusingpressurizedliquids(hydrostatictesting).Forfieldleaktestingusingpressurizedliquids,seePracticeF2164.1.3Leaktestingwithpressurizedgaseousmediashallbeusedonlyifoneofthefollowingconditionsexists:1.3.1Thepipingsystemissodesignedthatitcannotbefilledwithaliquid,or1.3.2Thepipingsystemservicecannottoleratetracesofliquidtestingmedia.1.4Wherehydrostatictestingisspecifiedincontractdocumentsorbyt......
【中国标准分类号】:P94
【国际标准分类号】:23_040_20
【页数】:8P.;A4
【正文语种】:英语