The welding operation of polyethylene wire mesh composite pipe is simple, and the details in the welding process are ignored. The main reasons for the welding failure are:
During welding, different axes of the pipeline are commonly known as "different strength", and electric fusion fixture is not used to fix the pipeline; Make the pipe subject to external force during welding; If no line is drawn, the socket of pipe fittings is not in place, resulting in empty welding or socket over position; The gradient of the extraction pipe fittings is large, and the pipe heating wire intensive area (heating area) is exposed to the air, so the heat cannot be transferred to the pipe fittings in time, causing the carbonization of overheated polyethylene (PE); The waiting time for welding is too long, and the welding surface is polluted due to untimely welding, and the temperature difference is large due to human factors. Due to the large temperature difference, the pipeline will experience empty welding and over positioning due to heat expansion and cold contraction; The package of electric melting pipe fittings is removed too early at the construction site, and exposed at the construction site, which pollutes the welding surface of electric melting pipe fittings; The oxide skin on the surface of pipe fittings is not completely scraped or even not scraped, and the welding surface is delaminated; The electric melting saddle tee violates the operation process. It is drilled before welding. Because the design of the saddle tee punching cutter is usually chip free cutting, the force used in drilling is very large, leading to the deformation stress of the saddle body to reach the viscous strain of resistance. This kind of strain can only be recovered after a certain period of time. The welding surface has a large gap, and the pipe leaks radially after welding; The electric fusion welding machine does not have the function of voltage protection, and continues to weld when the voltage does not meet the welding requirements, exceeding the welding parameters specified by the manufacturer of electric fusion pipe fittings; If the specified cooling time is not reached after welding, remove the fixed fixture or fixed object, and move the pipeline; No corresponding safeguard measures have been taken for the harsh environment of strong wind, rain and low temperature. The manufacturer of electric melting pipe fittings conducts welding under stress. The melting materials squeeze the heating wires together under the action of external force. The heat cannot be transmitted to the pipe fittings, which causes the materials to degrade or even carbonize at high temperatures, leading to welding failure and pressure leakage. When heating the electric melting pipe fittings, the polyethylene is in the molten state (PE) and the volume expands by about 20%. Under the action of external force, they force the heating wire to shift and concentrate, generating a lot of heat energy. They are concentrated on the observation hole to melt the solid material at the observation hole into liquid, open the material at the observation hole to flow out of the pipe page, and the PE pipe fitting manufacturer makes heating wire at one side of the pipe fitting and pipe page, leading to welding failure.
