... ISO, API Seamless Steel Tubes for low and Medium Pressure BoilersSpecificationsChina StandardSteel GradeStandardseamless steel tubesGB/T8162-199910, ... -199910, 20ASTM A179, ASTM A192for low and Medium Pressure BoilersASTM SA179,SA192, BS3059Seamless Steel TubesGB6479-8610, ... , 15CrMo, 12Cr2MoISO 9329-2-1997 for high pressure --Chemical fertilizer equipmentASTM A161-94Seamless steel tubesGB9948-8610 ...