1.seamless high pressure bolier pipe 2.O.D:6-750mm,W.T:1- 60mm 3.standard:GB5310,ASTM,DIN,BS 4.material:20G,15MoG,12Cr1MoV 1.seamless high pressure bolier pipe 2.O.D:6-750mm,W.T:1- 60mm 3.standard:GB5310,ASTM,DIN,BS 4.material:20G,15MoG,12Cr1MoVGseamless high pressure bolier pipe1. material:20G,20MnG,15MoG,12Cr1MoVG,10#,20# etc.2. standard:GB5.10-1999,ASTM A106-96a,ASTM A213-95a,JIS G3461-1998, ...