... and 1 welding steel pipe product line. We manufactures seamless steel pipe and steel-plate pipe ranging from φ38mm--φ127mmWe ... , 12Cr1MoVG, 15CrMoG, Cr5Mo, WB36, 10CrMo910, T91, N80, 5312 special pipe for ships, 45Mn2, 40Cr, 20Cr, 27SiMn, 35CrMo, low and ... pipeGB3087-1999, High-pressure boiler pipe GB5310-1995, pipes special for urea fertilizer GB6479-2000, cracking Pipe for petroleum GB9948-1988.