Grinding the Pipe Ends of Seamless Steel Pipes:

After cutting the pipes, an angle grinder should be used to grind the plastic layer at the pipe ends. This step is crucial to prevent the plastic layer from melting or burning during flange welding, which could damage the pipe. The angle grinder is used specifically to ensure the plastic layer at the pipe ends is properly ground down.

Plastic Coating of Seamless Steel Pipes:

Once grinding is completed, heat the external pipe ends using an oxygen-acetylene flame until the internal plastic layer starts to melt slightly. Then, skilled technicians apply prepared plastic powder evenly to the pipe ends. It is essential to ensure that the plastic coating is applied thoroughly, especially on the flange, up to the stop line for water sealing.

This process requires careful control of the heating temperature. If the temperature is too high, bubbles may form in the plastic coating. Conversely, if the temperature is too low, the plastic powder will not melt completely. Both scenarios can lead to the plastic layer peeling off after the pipes are put into use, resulting in corrosion and damage to the seamless steel section.

Cutting Seamless Steel Pipes:

Based on the required pipeline length, cut the pipes using a metal saw or a toothless saw. During cutting, especially when using water welding, it is imperative to protect the original material. Use fireproof and heat-resistant materials as shields at both ends of the cut to catch falling sparks and hot iron droplets, thereby preserving the original plastic layer of the material.

Connecting Seamless Steel Pipes:

After the plastic coating process, connect and install the pipes and fittings. During the connection process, place a rubber gasket between the flanges and tighten the bolts until a sealed state is achieved.

These detailed steps ensure the integrity and longevity of seamless steel pipes, preventing damage and ensuring optimal performance.