This technology cover the steel tube with thermal insulation and anti corrosive coating layer on the pipeline and is the first one in China. Compared to the other methods, it has the superior advantage such as continuous operation, high production efficiency, low cost, energy conservation, pollution-free, etc. In 1995, it won the second prize of state scientific technical progress and now has reached the international advanced level after several modificaltions.
　　The thermal insulation and anti-corrosive manufacturing lines for steel tubes with one-step forming method have high degree of automation. and the qualities of thermal insulation and anti corrosive coating fully meet the national standards.
　　Since the successful development in 1983, this technology has the working range of φ48mm-φ1000mm after twenty years' improvement with high resistance to temperature of the insulating layer (high temperature foam and high temperature compound foam encasing). Good derusting effects, (on-line shot blasting can be above Sa2-Sa3). The major equipment correction machine in the process has been changed into full hydromatic correction machine with correcting scope up to above φ48mm-φ1000mm, high correcting precision and steady and reliable operation. It has overcome the disadvantage of frequent faults of the electrical correction machine in the watery environment. Meanwhile, the pipe feed-in machine adopts multiroll impaction transmission to make the transmission of steel tubes steady and straight and overcome the eccentricity of the foaming due to the unsteady feed-in.
　　The heat-insulated anti corrosive coating steel tube is mainly used as crude oil transportation piping. direct burial heat supply pipeline and thermal insulation and corrosion protection of the piping of refrigeration system and has a wide application prospects and very high return on investment. It can be used in projects of central heating unit, long-distance fuel transfer, water supply, air supply etc.