2011 steel pipe knowledge: a new method for the classification of steel pipes Shandong Seamless Steel Tube Factory supplies steel pipes as an important part of steel products. Because of its manufacturing process and the shape of the pipe blank used, it is divided into seamless steel pipe (round billet) and welded steel pipe (board, Blank) two major categories. (1) Seamless steel tubes are classified into hot-rolled (extruded) seamless steel tubes and cold drawn (rolled) seamless steel tubes because of their different manufacturing processes. Cold drawn (rolled) tube is divided into two kinds of round tube and shaped tube. a. Process Overview Hot-Rolled (Extruded Seamless Steel Tube): Round Billet → Heating → Perforated → Three-Roll Rolling, Continuous Rolling or Extrusion → Stripping → Sizing (or Reducing) → Cooling → Blanking Tube → Straightening → Hydrostatic test (or flaw detection) → mark → storage. Cold drawn (rolled) seamless steel tube: round tube blank → heating → piercing → start → annealing → pickling → oil coating (copper plating) → multi-pass cold drawing (cold rolling) → blank tube → heat treatment → straightening → Hydrostatic test (flaw detection) → mark → storage. b. Seamless steel tubes, due to their different uses, are divided into the following varieties: GB/T8162-1999 (structural seamless steel tubes). Mainly used for general structure and mechanical structure. The representative material (brand): carbon steel 20,45 steel; alloy steel Q345, 20Cr, 40Cr, 20CrMo, 30-35CrMo, 42CrMo and so on. GB/T8163-1999 (transport fluid seamless steel pipe). It is mainly used for conveying fluid pipelines in engineering and large-scale equipment. Representative material (brand) is 20, Q345 and so on. GB3087-1999 (Seamless steel tubes for low and medium pressure boilers). Mainly used for industrial boilers and domestic boilers to transport low and medium pressure fluids. Representative materials for the 10,20 steel. GB5310-1995 (high pressure boiler seamless steel tubes). Mainly used in power station and nuclear power plant boilers on high temperature, high pressure conveying fluid headers and pipes. Representative materials are 20G, 12Cr1MoVG, 15CrMoG and so on. GB5312-1999 (Carbon and carbon-manganese steel seamless steel tubes for ships). Mainly used for ship boiler and superheater I, II pressure pipe. Representative materials for the 360,410,460 steel grade. GB1479-2000 (seamless steel pipe for high pressure fertilizer equipment). Shandong Seamless Steel Tube Factory () is a company that specializes in seamless steel pipe production, processing and sales. The company's main imports of all kinds of domestic steel pipe, stainless steel pipe, carbon steel pipe, sheet metal, pipe fittings and welding materials. The company has a large inventory of products. Tianjin Tiangang, Baotou Baotou Steel, Shanghai Baosteel, Chengdu Panzhihua Iron and Steel, Hubei Metallurgical Steel, Xining Special Steel and other large steel plant excellent agents. And establish a solid business relationship with Shandong Seamless Steel Tube Plant and Dagang Steel Plant. Can be customized for a variety of large-caliber, special thick-walled, special materials of seamless steel pipe and alloy steel pipe. Company abbreviation: Shandong Seamless Steel Tube Factory Contact: Jiang Zhenting Jiang Tonghe Wang Rong Tel: 0635-2111146 8880230 8887733 Mobile number: 13869581819 13562039893 13869581819 Fax number: 0635-8887733 NetEase mailbox: Company website: http://