Alloy Pipe,Pipe for chemical fertilizer facility ,Marine Pipe,Casing Pipe,Drill Pipe,Oil Pipe,Structure Pipe ,Pipe of Pipelines Code NO.VarietyNormal Steel GradeStandard NO.1Structure pipe10,20,35,45,Q235,Q295,Q345,40Cr etcGB/T81622Pipe for Liquid Transportation10,20,Q345 etcGB/T81633High Pressure Boiler Tube20G,12Cr1MoVG,20MnG,25MnG,15Cr1MoVGGB53104Low and Medium Pressure Boiler Tube10, ...