... : GB, ISO , API certificate. 2: 80000 ton per month. 3: fluid tube,boiler tube Carbon steel, and alloy steelStandardASTM/DIN/GB/JIS ... -11000002Oil line pipeB,X42~X60(L245~L415)50003high-pressure boiler tube20G50004lower/medium-pressure boiler tube10#,20#,A,B60005Transmission fluid tube10#,20#,Q295 ...