Seamless (Seamless tube) is a kind of hollow cross section, no seams around the long bar of steel. Currently, a total world production of seamless pipe manufacturing plant more than 1850 more than 5100 companies in more than 110 countries, under which production has more than 260 oil pipe plant more than 170 companies in 44 countries under 1. structure seamless pipe (GB/T8162-2008) is used for seamless general structure and mechanical structure. 2 fluid seamless pipe (GB/T8163-2008) is used to transport general seamless water, oil, gas and other fluids. 3 low-pressure boiler seamless pipe (GB3087-2008) is used in the manufacture of various structural low and medium pressure boiler superheated steam pipes, boiling water pipes and superheated steam locomotive boiler tubes, opium pipe, small pipe and brick arch effective high-quality carbon structural steel hot-rolled and cold drawn (rolled) seamless. 4 high-pressure boiler seamless pipe (GB5310-2008) is used to manufacture high-quality carbon steel and more pressure water tube boiler heating surface with steel, alloy steel and heat-resistant stainless steel seamless pipe. 5 fertilizer equipment with high-pressure seamless pipe (GB6479-2000) is applied to the working temperature of -40 ~ 400 ℃, working pressure of high-quality carbon steel and alloy steel 10 ~ 30Ma of chemical equipment and pipeline seamless. 6. Petroleum cracking seamless pipe (GB9948-2006) is applied to the oil refinery furnace tubes, heat exchangers and pipe seamless. 7. Geological drilling pipe (YB235-70) is for the geological department of the steel core drilling, use can be divided into the drill pipe, drill collars, core pipe, casing and precipitation tubes. 8 diamond core drilling seamless pipe (GB3423-82) is a drill, core rods for diamond core drilling, casing seamless. 9 oil drilling pipe (YB528-65) is used to thicken the oil drilling within or outside the thick ends of seamless pipe