1. Influence of current and voltage fluctuation on interface quality: the resistance of electric melting pipe fittings of PE internal pre heating wire is stable after the factory quality is qualified. At this time, the heating power of the electric heating wire is only related to the voltage provided by the welding power supply. The heating power changes with the change of the quality of the welding interface due to the fluctuation of the heating power.
a. It is not allowed to directly connect the power supply for welding with the steel mesh composite pipe under the high-power equipment, and the same cable is used.
b. The welding machine is generally 20 meters away from the power supply at 50 meters 5 mm2 input cable. When the welding machine is 50-100 meters away from the power supply, 40-100 meters of mm2 input cable shall be used. When the welding machine is 100 meters away from the power supply, the input cable or motor shall be thickened. Cable reel is strictly prohibited.
2. The working temperature affects the quality of the interface. The factory specification of PE pipe fittings is generally based on the working temperature of 20 ° C. If the working temperature in the welding link is different, it means that the heat conduction standard of the pipe in the welding link changes, which is directly related to the welding quality. Therefore, the operating temperature must be monitored. The operating temperature here refers to the ambient temperature around the welding point. The correction value of welding time is described in detail in the pipe certificate.
3. The impact of bad operation on the interface quality The so-called bad operation is mainly caused by the construction personnel's weak sense of responsibility, their failure to operate according to the operation procedures, and the connection position due to oil stains, water, soil and other reasons. Therefore, before welding, each operation process must be carefully followed according to the operation procedures to obtain a good welding interface.
Common phenomena are as follows:
a. The connecting port of PE pipe is not scraped or handled improperly, and the port is not chamfered or broken.
b. Incorrect positioning, insufficient insertion depth of pipe fittings, PE pipe and PE pipe fittings are not on the same axis
c. The coil pipe fittings are not straightened before welding, or the pipe fittings with large bending deformation are not straightened.
