... steel tubes and transport liquid, gas, oil etc.Quality Standard:GB/T 8163: Seamless steel tubes for liquid serviceGB 3087: Seamless ... Steel Tubes for Low and Medium PressureGB 5310: Seamless steel tubes and pipes for high pressure boilerASTM A106 ... 8163: 10#, 20#, 35#, 45#, 16MN(Q345B)GB 3087: 10#, 20#, 35#, 45#, 16MN(Q345B)GB 5310: 20G, 12Cr1MoV, 12Cr1MoVG, 12CrMoGASTM A106: Gr ...