Double submerged arc welded pipes, resistance welding, high frequency welding straight seam steel pipe factory direct, high quality and low price ---- company specializing in the production of thermal expansion pipe, spiral steel pipe, high-frequency welded pipe, annual distribution of Baotou Steel, Tianjin Steel and steel posterior wall seamless steel pipe plant, I plant sided submerged arc welding process in North China's premier, 35 technicians, thermal expansion pipe equipment unit is a German import unit, the product error is small, accurate scale. The public are welcome to visit and negotiate. Tel 0317-6083098