This product is a new type of pipeline material newly developed in China. It has a plastic coated protective layer inside and outside. The middle is a composite structure of reinforced welded steel pipe or seamless pressure-bearing steel pipe, which overcomes the rust, corrosion and high of the steel pipe itself. The pollution and the defects of low strength and easy deformation of plastic pipes integrate the common advantages of steel pipes and plastic products, and are environmentally friendly products promoted by the state. The plastic coated composite steel pipe is melted on the inner wall of the steel pipe with a thickness of 0.5 to 1.0 mm of polyethylene (PE) resin, ethylene-acrylic acid copolymer (EAA), epoxy (EP) powder, non-toxic polypropylene (PP) or Steel-plastic composite pipe made of organic materials such as non-toxic polyvinyl chloride (PVC), which not only has the advantages of high strength, easy connection and water flow impact of steel pipes, but also overcomes the corrosion, pollution and scaling of steel pipes. The plastic tube has low strength and poor fire performance, and the design life can reach 50 years. The main disadvantage is that when the installation is not carried out, the cutting surface should be applied with the non-toxic room temperature curing glue provided by the manufacturer when bending, hot working and electric welding cutting. The main specifications are DN15 - DN300.