... steel Pipe Standards and Grades:GB5310, GB3087, 10#, 20#, 20G, 20MnG,12Cr1MoVG, 15CrMoG,ASTM A335(P1/P11/ ... P265GH,16Mo3)JIS G3458 Alloy Steel Pipes (STPA 12/ 20/ 22/ 23/ 24/ 25/ 26)JIS G3462 Alloy ... for Boiler and Heat Exchanger Tubes (STBA12/ 13/ 20/ 22/23)JIS G3467 Steel Tubes for Fired Heater ... 22/ 23/ 24/ 25/ 26)Specification: O.D.20-480mm, W.T. 2- 60mm. Application: Generally for boilers and heat ...