... PN2~PN422)G20633-97,HG20612-97,ASME16.20,API6B,JB/T89-943)material:soft iron,carbon steel,stainless steel and so ... ,BX,RX)standardsHG20633-97,HG20612-97,ASME16.20,API6B,JB/T89-94material selectedsoft iron,carbon steel,SS304,SS316,F5,F61temperaturechanges with ...