The 3 ERW welded steel pipe production line can produce O.D. 10-610mm with W.T. 0.5-15mm welded steel pipes,including hollow section,galvanized steel pipe,etc. The largest sprial steel pipe production line cover 7 lines from 219mm-3500mm. The large longitudinal submerged-arc welded steel pipes lines can produce the O.D. 457-1420mm with W.T. 7-60mm with one seam and two seams for above 1500mm.