Steel-plastic composite pipe, the product uses seamless steel pipe and welded steel pipe as the base pipe, and the inner wall is coated with high-adhesion, anti-corrosion, food-grade hygienic polyethylene powder coating or epoxy resin coating. The galvanized inner plastic composite steel pipe for water supply made of pretreatment, preheating, internal coating, leveling and post-treatment processes is an upgraded product of traditional galvanized pipe. Plastic composite steel pipe is made of welded steel pipe and seamless steel pipe as the base material, and the inner and outer walls are coated with epoxy resin or polyethylene powder. It is a green environmental protection material with anticorrosion, corrosion resistance, non-toxic and non-radiation, and is used in various fluid transportation. The base pipe is a straight seam welded steel pipe should meet the requirements of GB/T3091-2008 for the base pipe; if the base pipe is a seamless steel pipe, it should meet the requirements of GB/T8163-2008 for the base pipe; the base pipe is a spiral seam submerged arc welded steel pipe should meet the requirements of SY/T5037-2000 for the base pipe. This product has the following major advantages. 1. Retains the steel and strength of traditional metal pipes, far superior to plastic pipes, aluminum-plastic pipes; fire internal and external plastic coated pipe plastic composite steel pipe 2, with the characteristics of smooth inner wall, small friction resistance and no scaling, the outer wall is more beautiful and luxurious; 3, light weight, good toughness, impact resistance, high compressive strength; the applicable temperature is wider -30℃~100℃; 4, and pipe The connection method of the parts can be twisted wire, socket, flange, groove, Welding, etc., in a variety of ways, labor and labor saving; 5. The thermal expansion coefficient difference with the pipe fitting is small, which is safer and more reliable; 6. Reasonable price-performance ratio, low comprehensive cost, and more economical than copper and stainless steel pipes. The steel belt in the middle of the hole mesh steel belt is punched with many holes, so that the inner and outer PE are organically combined into one, so that the composite problem of steel and plastic is solved, but the oxygen resistance performance of the steel plastic pipe is sacrificed. The steel wire skeleton is developed on the basis of the hole mesh steel strip steel plastic pipe. Since the hole mesh steel strip has lost the performance of high pressure resistance and oxygen resistance, and only plays a part of the pressure-bearing role, then why should the steel strip molding, butt welding and other difficult processes, simply wrap the braided steel wire directly on the pipe wall, and can also play a pressure-bearing role, so the steel wire skeleton steel plastic appeared Pipe, the performance of this kind of pipe and the hole mesh steel strip Plastic pipes are basically similar.