Big Diameter Welded Pipes Grade:304/304l/316/316l/310s/321 Standards: ASTM A312/213/511,GB/T14975,GB/T14976, Big Diameter Welded PipesFeatures:1) Standards: GB/T14975-2002, GB/T14976-2002, GB13296-91, GB9948-88, ASTM A312, ASTM A213, ASTM A269, ASTM A511,JIS3459,DIN174562) Our products are corrosion and high-temperature resistant3) The main standards are 304, 304L, 316, 316L, 321, 321H, 310S, ...