Products: Seamless Steel Tubes for low and Medium Pressure Boilers Size: 1/4"-24" Certificate: ... ISO, API Seamless Steel Tubes for low and Medium Pressure BoilersSpecificationsChina StandardSteel GradeStandardseamless steel tubesGB/T8162-199910, 20, ... TubesGB3087-199910, 20ASTM A179, ASTM A192for low and Medium Pressure BoilersASTM SA179,SA192, BS3059Seamless Steel TubesGB6479-8610, 20G ...