... 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 ... , superheater, and heat-exchanger tubersOD: 21.3mm-711mmWH:sch10-schXxs ASTM A213M :T1, T5, T9,T11,T22, T91, T91ASTM A335: P1 ... -steel boiler, superheater,and heat-exchanger tube Alloy Steel Pipe ASTM A213