1. Shot blasting process

Shot blasting treatment is necessary before foaming.

First, this process polished outer surface of the qualified pipes,remove the oxide,dust and oil stain of the pipe surface

Then increase adhesion of the pipe.

Last,It improved the adhensive strength between the polyurethane insulation layer and the pipe.

2.Electric corona treatment process

Electrode corona process carry out the principle of high pressure electrode discharge. To make electric corona treatment for the inner surface of PE pipes.

3.Polyurethane foam

We use PU600 high-pressure foam machine.and its capacity of injection materials reaches 600L/min, pressure of injection material  reaches 30MPa.Our polyurethane raw material is from Bayer Company in German.Which is fluorine-free products with best quality. Also it  meet all the data of our chinese Ministry of Construction and European standards. , it can continously working under the temperature  148℃ and more than 30 years’s life..

4.Sweating soldering process

Firstly, this process makes the V type welding junction melted.at the same time, Under the pressure of welding machine, it makes the extruded melted PE to be welded tightly on the junction.

5.Hot plate welding process

According to the principle of PE sweating soldering, to preheat the junction of the pipe with different angles on the hot plate. after it reaches the resonable temperature.quickly exert the axial pressure on the pipes to enable the melted pipe orifice be welded perfect.

6.Electric sweating soldering interface process

Through the method of electrical heating, the joint coupling can be used with PE outer protecting pipes, which has high welding strngth, and is applicable for the construction that adopts various laying direct-buried prefabricated insulation pipe joints.