... 6Alloy SteelASTM / ASME A 335 GR P 1 , P 5 , P 9 , P 11 , P 12 , P 22 , P 23 , P 91Technical Parameters of Seamless Steel PipeA53: ... property Class and SortChemical componentsMechanical propertyC(Max)Mn(Max)P(Max)S(Max)Tensile Strength(Min)Yield Strength(Min ... boilerSeamless pipes for petroleum20, 12CrMo,15CrMoGB9948-8810-530*1.5-36Boiler pipes for refinery, heat-exchanging pipes, seamless steel ...