What are the precautions for the bellows construction connection method?

The large-diameter steel belt corrugated pipe has become a well-known product for many people. Many people have a question. The diameter of the pipe is so large that it is definitely not convenient to connect. The caliber can be connected freely, saving time and effort. Below, the supplier will introduce you the connection method used in the construction of the corrugated pipe.

HDPE steel belt reinforced polyethylene spiral corrugated pipe is mainly divided into electric hot melt connection, heat shrinkable tape connection, hot melt extrusion welding or a combination of various connections, and the connection is firm. Reliable connections allow the pipeline to reach zero leakage.

First, the structure of hot melt extrusion welding: Hot melt extrusion welding uses a special hot air extrusion welding tool. First, the pipe is heated at both ends of the connection. A fusion joining method. The connection structure is a connection method in which a polyethylene material is fused into a whole, which is a rigid connection.

Extrusion welding is based on the basic principle of molecular thermal motion. The PE electrode is heated by an extrusion welding gun (the electrode is changed from a solid to a viscous fluid) and extruded. At the same time, the hot air gun configured on the welding torch heats the to-be-welded surface of the welded PE pipe. After external force, the PE materials at both ends of the joint are bonded to each other, so that they are well diffused and intertwined with each other, and the corrugated metal pipe is connected As a whole, so as to achieve the effect of welding.

Second, construction points of hot melt extrusion welding:

1. Check

Before welding, check whether the two ends of the pipe to be welded are cut flat (if the end face is not flat, repair should be performed). Control the surface to be welded in the center of the trough of the pipe, and adjust the two welded pipes to the same axis (to make the pipe disconnected as aligned as possible); leave a gap of 1-3mm at the interface to facilitate welding (but the maximum gap generally does not exceed 5mm). If the requirements are not met, the interface must be partially repaired with a tool. The trimming work can be performed from outside or inside the pipe (pipes of φ800 or more). The welding area must be kept clean and dry. There must be no dust and other impurities; the inner and outer surfaces of the welding area should be polished to remove the oxide surface layer.

2. Welding rod

The welding electrode used for welding should generally be provided by the pipe manufacturer. It must be the same as the polyethylene used in the production of the pipe or a material that is compatible with the pipe. The steel corrugated pipe requires a circular cross section. Requires welding torch performance requirements. The electrode must also be clean, dry and free of any stains.

3.Extrusion welding machine

Emphasis must be placed on the use of a good extrusion welder with a hot air unit. When welding, the hot air device must preheat the polyethylene at the joint end of the welded pipe, so that the extruded molten polyethylene can be integrated with the pipe. All welding sections must be full, and there must be no leaks or fractures.

Corrugated Culvert Pipe

4.Double-sided welding

For pipes with a diameter greater than 800mm, internal and external double-sided welding is generally required.

5. Welding process

Set the temperature of the melt and hot air according to the environmental conditions; maintain a certain welding pressure on the melt; have a correspondingly slow cooling time. In short, all welding processes and operating requirements shall be performed in accordance with the welding processes and operating requirements provided by the pipe manufacturer.