... (SEAMLESS)DN300DN2000(WELDED) WALL THICKNESS1.5~150MATERIAL:CARBON STEEL, ALLOY STEEL, STAINLESS STEEL OPERATIVE NORM:GB, ELECTRICAL POWER, CHEMISTRY,PETROLEUM ... support certificate of quality; the ASME U S steel seal manufacture license award by American Society of ... for the requirement of assembly, welding, heat treatment, hydraulic pressure, physics and chemistry, non-destructive testPaymentL/C,T ...