The -9711 standard large diameter spiral steel pipe Inventory cheap sales - company specializing in the production of thermal expansion pipe, spiral steel pipe, high frequency welded pipe, Baotou Steel, Tianjin Steel and other steel mills annual distribution of the posterior wall of seamless steel tubes, I plant sided buried arc welding process in North China's premier, 35 technicians, thermal expansion pipe equipment unit is a German import unit error is small, accurate scale. The public are welcome to visit and negotiate.