Factors affecting the welding quality of PE electrofusion pipe fittings

1. The impact of voltage and current fluctuations on interface quality: For PE electrofusion pipe fittings with qualified quality shipped from the factory, the resistance value of the internal pre-resistance wire is constant. At this time, the heating power of the resistance wire is only related to the voltage provided by the welding power supply, and the heating power changes accordingly. The quality of the welding interface changes due to the fluctuation of the heating power.
a. High-power machines cannot be directly connected to the power supply for splicing and share the same cable.
b. Generally, when the electric fusion welding machine is within 50 meters from the power source, a 2.5mm2 input cable is used. When the welding machine is 50-100 meters away from the power source, a 4mm2 input cable must be used. When the electrofusion welding machine is 100 meters away from the power source, the input cable must be thickened or connected to a generator. It is prohibited to use the cable in a coiled manner.
2. The environmental temperature affects the quality of the interface. According to the factory standards of PE pipe fittings, the welding time parameters are generally based on an ambient temperature of 20°C as the design standard. If the ambient temperature is different during the welding process, it means that the heat conduction conditions of the pipe fittings change during the welding process, which directly affects the welding quality. Therefore, the ambient temperature must be monitored, here the ambient temperature around the welding point. The welding time correction value is detailed in the pipe fitting certificate.
3. The impact of bad operation on the quality of the interface. The so-called bad operation is mainly caused by the construction personnel's lack of responsibility and failure to follow the operating procedures. The connection parts are caused by oil, water, soil and other reasons. Therefore, before welding, each operating step must be carefully checked according to the operating procedures to obtain an excellent welding interface.
Common phenomena are as follows:
a. The connection port of the PE pipe is not scraped or processed incorrectly, and the port is not chamfered or has debris.
b. The positioning is incorrect, the pipe insertion depth is not enough, and the PE pipe and PE pipe fittings are not on the same axis.
c. The coiled pipes are not straightened before welding, or the pipes with large bending deformation are not rounded, etc.