Stock sales of thermal expansion of the diameter steel pipe, thick-walled welded steel pipe! ----- Our company specializes in production of thermal expansion pipe, spiral steel pipe, high frequency welded pipe, the annual distribution of Baotou Steel, Tianjin Steel and other steel mills in the posterior wall of seamless steel tubes, I plant sided submerged 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.