... :Tigersteel Certificate:ISO,API ERW Pipe/ ERW Tube Professional Manufacturer 1)Standard:GB, DIN, JIS, ASTM2 ... and middle pressure fluid transportation pipe lines b.Casing tube c.Boiler pipes d.Conveyance of electricity ... 2. Anti-H2S corrosion, Anti-CO2 corrosionGrade: GR B, X42-X80Specification: 219.1 - 610 mm*4 ... : ASTM A53M, JIS G3466Grade: GR.A, GR.B, STKR400, STKR490Specification: 219.1-630mm*4-20mm ...