... /API 5L/GRB/A335/ST37/ST52. Our factory manufacture galvanized pipe,steel pipe,square pipe,pipe fitting.1.Standard: ANSI B16.9/16.28, DIN ... pipe,seamless pipe,carbon steel seamless pipe, 7.Special design available 8.Quality: ISO9001 : ISO2000 , ABS , BV 9.outer packing: Seaworthy plywood case galvanized pipe ...