Alloy steel pipe 1, standard:ASTM A213 ASTM A335 2: SIZE:1/2''-28'' 4:Wall thickness:2-30mm Seamless Alloy pipe ... per ASTM A213M ASTM A335 for boiler, superheater, and heat- ... A335: P1,P5,P9,P11,P22, P91, P92 Standard Specification for seamless Ferritic and Austenitic Alloy-steel boiler, superheater,and heat-exchanger tube Alloy Steel Pipe ASTM A335 ...