Tianjin Shuangjie Steel Pipe Co., Ltd , a professional manufacturer of ERW steel pipe ,was founded in 1978 . Our factory occupies 270,000 square meters and almost 700 employees are working inside.Our pipes are mainly used in the civic water supply, gas supply, oil transportation, construction.Our annual output up to over 200 thousand metric tons. Registered trademark is "Shuangjie" brand. Since the establishment of the factory in 1978, we adhere to the management conception of "Top Quality and Consumerism", and improve the quality control system, as a result, "Shuangjie" brand steel pipe is appointed as preferred designated product in Tianjin three-years' Gasworks Project, and enjoying fast sale constantly during 20 years in Southeast Asia, Europe, America, Middle East Asia, more than 20 countries and regions, and reputed for diversified specifications, advanced craftsmanship and steady quality in both domestic and overseas markets. In 1997, Shuangjie has passed ISO9002 Quality System Certification, and obtained Certificate of Authority to Use Official Monogram issued by API Organization in 2001. Oil pipeline of ∮325mm diameter is our mainstay products developed by investing over 60 million RMB in 1999 and introducing advanced anneal and electronic test equipments from USA and Japan so as to ensure fine and steady quality of final products, annual yields of about 120 thousand metric tons, widely used in oil and natural gas industries. Oil pipeline of ∮610mm diameter is our mainstay products developed by investing over 364 million RMB in 2003 and introducing advanced equipments , annual yields of about 500 thousand metric tons, widely used in oil and natural gas industries. Should you have any inquires about ERW pipe and hot dipped galvanized steel pipe ,please feel free to contact us !