Product Code:SAE AS81820 Title:Bearings, Plain, Self-Aligning, Self-Lubricating, Low Speed Oscillation Issuing Committee:Acbg Plain Bearing Committee Scope:This standard covers plain spherical bearings which are self aligning and self lubricating by utilizing polytetrafluoroethylene (PTFE in a fabric composite or molded material that is bonded to the inner diameter surface of the race and when specified, to the bore diameter surface of the ball. These bearings are for use in the temperature range 65 to +325 掳F ( 54 to +163 掳C).【英文标准名称】:StandardPracticeforUltrasonicExaminationofTurbine-GeneratorSteelRetainingRings 【原文标准名称】:涡轮发电机钢定位环的超声波检验的标准作法 【标准号】:ASTMA531/A531M-1991(2006) 【标准状态】:现行 【国别】:美国 【发布日期】:1991 【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】:A01.06 【标准类型】:(Practice) 【标准水平】:() 【中文主题词】: 【英文主题词】: 【摘要】:1.1Thispracticecoverstheprocedurestobefollowedwhenperformingultrasonicshearandlongitudinalwavetestsonturbine-generatorretainingringswithaninsidediametertowallthicknessratioequaltoorgreaterthan5:1andwithwallthicknessesfrom1to4in.(25to102mm).1.2Althoughthispracticedescribesmethodsofultrasonicallytestingretainingringsbyeitherthecontactorimmersionmethod,itshallnotrestricttheuseofimprovedinspectionmethodsastheyaredeveloped.Itisrecognizedthattechniquesforexaminationandevaluationmaybechoseninordertoenhanceorimprovetheresultsortoaccommodatevariationsinprocedures,equipment,orcapabilities.Consideringthesecharacteristics,forgingsmaybeinspectedbyacombinationofboththecontactandtheimmersionmethods,asmutuallyagreeduponbetweenthemanufacturerandthepurchaser.1.3Thispracticeandtheapplicablematerialspecificationsareexpressedinbothinch-poundunitsandSIunits.However,unlesstheorderspecifiestheapplicable"M"specificationdesignationSIunits,thematerialshallbefurnishedtoinch-poundunits.Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwithitsuse.Itistheresponsibilityoftheuserofthisstandardtoestablishappropriatesafetyandhealthpracticesanddeterminetheapplicabilityofregulatorylimitationspriortouse. 【中国标准分类号】:H26 【国际标准分类号】:21_060_60 【页数】:5P.;A4 【正文语种】:英语