Generally speaking, the electric fusion welding machine welds pipes with a fuse machine. Electric fusion welding machine is with high speed and low cost and suitable for welding PE water supply pipes and PE gas pipes.
The electric fusion welding of electric welding machine includes hot-melt butt joint and hot-melt socket joint, which is the hot-melt connection mode of polyethylene pipeline system.
Hot-melt socket welding is suitable for pipe fittings with small diameter. Because the pipe wall of pipe fittings with small diameter is thin and the cross section is small, it is difficult to guarantee the quality by butt joint. Hot-melt butt joint is suitable for pipe fittings with larger diameter, which saves materials and is easy to manufacture than socket joint. Because the oxidize is removed before welding, the welding pressure can be controlled and the quality can be easily guaranteed. From the development trend, hot-melt butt joint is the mainstream.
Experiments prove that pipes and fittings made of different grades of polyethylene (PE) pipe special materials can be connected by hot melting. However, because the materials used for polyethylene pipe fittings produced in China are not totally in line with the standard special materials for pipes, it is suggested that the polyethylene pipe fittings of different brands and batches should be tested first when they need to be hot-melt connected.
The technology and equipment for PE pipe welding by hot melting are relatively simple. In order to further ensure the quality, ultrasonic test should be adopted for testing the quality of hot-melt connection. But the field use has not become popular. At present, it is still rely on visual inspection in the field.
The guarantee of quality stability of hot-melt connection mainly depends on strictly observing the specified operating procedures. It is suggested that the production enterprises of polyethylene pipes and fittings should work out detailed operation procedures suitable for their own pipes and fittings through tests and inspections according to relevant specifications. They should also help the constructors master the operation procedures through training and consultation.
