longitudinally Submerged Arc Welding pipe (LSAW steel pipe) with steel ingot or a solid billet made by perforation of capillary, and then by hot rolling, cold rolling or cold. Straight seam welded steel pipe industry in our country has important place in the. According to incomplete statistics, China's existing seamless pipe production enterprises more than 240, longitudinal welded pipe unit of about 250 sets, with an annual output capacity of about about 4500000 tons. From the bore, < 76 mm, 35%, <φ 159-650, 25%.Look from breed, general purpose pipe 1900000 tons, accounting for 54%; oil pipe 760000 tons, accounting for 5.7%;hydraulic prop, precision tube 150000 tons, accounting for 4.3%; stainless steel tube, pipe, tube bearing of car of 50000 tons, accounting for 1.4%.
welded steel pipe according to a certain classification method and application thereof can be divided into:precision hydraulic tubes, cold-drawn precision steel, precision cold-rolled steel pipe, high precision steel, precision brighttube. Different materials and models of longitudinal welded pipe in use with a different value and function, in a process ofprocessing and production, make its use in different areas and industries.