... quality,timely delivery; 3>Had been approved by ASTM. alloy seamless steel tube: Material: 12Cr1MoV, P22(10CrMo910), T91, P91, P9, T9, WB36, ... Official API Monogram.2> Boiler and Super-heater Pipes,Seamless Pressure Pipes had been approved by CCS.3> The ... good cooperation with Chengdu Steel Group Co., Ltd., Baotou Steel Group Co., Ltd., Baoshan Steel Corporation and Tianjin Steel Pipe Group Co., Ltd ...