... All the production process are made under the ISO9001 strictly.Company info. Cangzhou Guyuan Steel Pipe Co., LTD is located ... Xinxing Steel Pipe Manufacture Co., LTD, online trading began in 1997. Currently our company is a large professional production at home ... system of production and testing equipment. For many years, our company for domestic coal-fired power, chemical, shipbuilding, metallurgy, ...