1. The influence of voltage and current fluctuations on the quality of the interface: For the PE electrofusion pipe fittings with qualified quality, 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, and the quality of the welding interface changes due to the fluctuation of the heating power.
a. It cannot be directly connected to the power supply for fusion splicing under high-power machines, sharing a single cable.
b. Generally, when the electric fusion welding machine is within 50 meters from the power supply, use a 2.5mm2 input cable. When the welding machine is 50-100 meters away from the power supply, the input cable of 4mm2 should be selected. When the electric fusion welding machine is 100 meters away from the power supply, the input cable should be thickened or the generator should be connected, and the coiled cable should not be used.
2. The environmental temperature affects the quality of the interface. The factory standard of PE pipe fittings, and the welding time parameters are generally based on the 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, it is necessary to monitor the ambient temperature, which is the ambient temperature around the splicing point. The correction value of welding time for the fittings is specified in the pipe fitting certificate.
3. Influence of bad operation on the quality of the interface The main reason for the so-called bad operation is that the construction personnel have a weak sense of responsibility, do not operate in accordance with the operating procedures, and the connection parts are caused by oil, water, soil and other reasons. Therefore, the operation steps must be carefully checked according to the operating procedures before welding, in order to obtain a good welding interface.
Common phenomena are as follows:
a. The connection port of the PE pipe is not scraped or processed properly, 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 have not been rounded.
