The seamless pipe has a hollow cross-section and is widely used as a pipeline for conveying fluids, such as octg pipes for conveying oil, natural gas, gas, water, and pipes for certain solid materials. Compared with welded pipes, seamless pipes have higher bending and torsional strength and better compression resistance, and are economical section steels.

1. Nozzle grinding: After cutting, use an angle grinder to grind the plastic layer of the nozzle. The purpose is to avoid melting or even burning of the plastic layer during flange welding to damage the pipe. Use an angle grinder to grind the nozzle plastic layer.

2. Plastic coating treatment: After grinding, use oxygen and acetylene to heat the nozzle outside the pipeline. Heating until the inner part of the plastic layer melts, and then the skilled worker will evenly coat the nozzle with the prepared plastic powder. It should be noted that the coating must be fully in place, and the plastic coating of the flange must be applied above the water stop line. This process should strictly control the heating temperature. If the temperature is too high, bubbles will be generated during the plastic coating process. If the temperature is too low, the plastic powder will not melt completely during the plastic coating process. In the above situations, the plastic layer will fall off after the pipeline is put into use, and eventually the steel pipe part of the pipeline will be corroded and damaged.

3. Cutting: According to the actual length of the pipeline, the pipeline should be cut with a metal saw or a toothless saw. When using water welding in the cutting process, there must be protection methods for raw materials. When cutting, fireproof and heat-resistant materials should be used as baffles at both ends of the fracture to catch the sparks and hot molten iron beans falling during cutting, so as to protect the original plastic layer of raw materials.

4. Pipeline connection: After the plastic repair is completed, the pipe and fittings are connected and installed. During the connection process, rubber pads are added between the flanges, and the bolts are tightened to a sealed state.

Plastic-coating the seamless pipe can not only adapt to the humid underground environment, but also withstand high and low temperatures, and has strong anti-interference ability