Plastic-coated steel pipes use welded or seamless steel pipes as the base material, with the inner and outer walls coated with epoxy resin or polyethylene powder. They are corrosion-resistant, erosion-resistant, non-toxic, and radiation-free, making them a green and environmentally friendly type of steel pipe. Plastic-coated steel pipes are used for various fluid transportation applications. For straight-seam welded steel pipes, the requirements should meet the standards of GB/T3091-2008; for seamless steel pipes, the requirements should meet the standards of GB/T8163-2008; and for spiral-seam submerged arc welded steel pipes, the requirements should meet the standards of SY/T5037-2000.

Plastic-coated steel pipes have several advantages:
1. They retain the rigidity and strength of traditional metal pipes, far superior to plastic pipes and aluminum-plastic composite pipes;
2. They feature a smooth inner wall, low friction resistance, and no scaling, while also boasting a more aesthetically pleasing and luxurious outer wall;
3. They are lightweight, tough, impact-resistant, and have high-pressure resistance; they also have a wider operating temperature range of -30℃ to 100℃.
4. Plastic-coated steel pipes can be connected to fittings using various methods such as threading, socketing, flanges, grooved connections, and welding, saving labor and effort.
5. The difference in thermal expansion coefficients at the connection points between plastic-coated steel pipes and fittings is small, ensuring greater safety and reliability.
6. Plastic-coated steel pipes offer a reasonable price-performance ratio, with lower overall costs, making them more economical than copper or stainless steel pipes. The steel strip in the middle of the perforated steel strip has many holes, which makes the inner and outer PE layers organically bonded together, thus solving the problem of the steel and plastic composite. However, it sacrifices the oxygen barrier performance of the steel-plastic pipe. Moreover, due to the presence of the perforated steel strip, the pressure resistance of this type of steel-plastic pipe is greatly reduced. Under high pressure working conditions, the steel pipe is prone to local bursting.