In recent years, polyethylene pipe has become the best choice of the city gas pipeline network and the low pressure water supply pipe networkdue due to its unique and good weld can be easy to connect, cracking resistance, environmental protection, health, recycling use and other characteristics. Along with the popularity of PE pressure piping application, PE fused fittings for its construction is convenient, reliable welding and get extensive application, especially the city gas field has been popular, also began to widely used in the field of water supply. Historical experience shows that practical application at home and abroad with polyethylene pipe service life of the basic equivalent reliable connection method of the welding. Therefore, fused fittings and electric welding machine is widely used and fast development. In addition, the steel wire web skeleton polyethylene compound feed pipe in recent years, with the advantages of PE pipe, and there was a more superior comprehensive performance than PE tube, especially in fast crack stress cracking resistance, creep resistance, continuous mechanical strength performance is better than that of pure PE pipe etc., so, also began to widely used for municipal water pipe. The main connection methods is electricity fusion welding, corresponding fused fittings and electric welding machine is developed.

Polyethylene pipe fusion welded principle

Polyethylene pipe fusion welded principle is embedded in the electric welding machine to the inner wall of fused pipe resistance wire heating, the heating energy to fittings and tubing connection interface melting. The gap at both ends of the tube closed, the interface of the melt zone and the melt under pressure at high temperature, interdiffusion of the molecular chain, if the interface to a depth of interdiffusion of the molecular chain entanglement necessary dimensions, natural cooling interface the necessary welding strength can be obtained, the formation of reliable solder connection pipe. According to the electrofusion welding principle and practice at home and abroad confirmed, pipeline can form a reliable solder connections and mainly by the fused pipe design, resistance temperature, resistance properties, fused welding power supply voltage supplied fittings and pipes stability and nature of the material pre- condition to connect the interface, connected to the interface between the slit width and uniformity, fittings and tubing clamp on the stability and condition, welding parameters, welding ambient temperature, the operator level and other factors.