Correct Welding and Docking of HDPE Pipe Make Installation More Efficient
What we know about the welding process:
Butt the operation fusion in high-density polyethylene pipes (HDPE) is based on the joining of two surfaces, which are heated by applying a specific heating temperature, applying precise pressure from between two points until both surfaces are finally Fusion.
Heat changes the molecular structure of the plastic from a crystalline to an amorphous state, thus creating a mixture of these molecules when pressure is applied. By cooling, the molecules return to their crystalline state, enabling excellent welding results.
In our daily installation and construction, no one wants to rework once the welding process is completed. Some are not implemented according to the correct operating procedures. We must rework, cut off the pipes, and gradually repeat the entire operation.
The correct process is as follows:
When installing butt equipment (including mechanical and hydraulic equipment), we must follow the manufacturer’s instructions for standardized operations.
To enable a good construction foundation, the two pipes must be aligned laterally using a press to avoid axial movement.
Once they are aligned and clean, the thermocouple must be heated until the appropriate melting temperature is reached: it will oscillate between 210±5ºC for wall thicknesses less than 10mm and for wall thicknesses greater than 10mm. It will be between 200±.
The surface to be welded must press the thermocouple with an intensity proportional to the diameter of the pipe and then gradually decrease until a regular bead forms around the circumference. (Look at the machine’s welding chart).
Once the heating time is over, remove the thermocouple (taking care not to touch the soft material) to briefly check that both ends have the same even fusion.
Put together immediately, gradually applying strength from lowest to highest (which will be indicated by pipe thickness) starting at 1.5 kg at both ends. Strength (look at the welding station of the machine).
For bead formation, the final pressure should be equal to the first pressure and maintained for the same time as indicated on the station, without using water, solvents, or streams of water to speed up the process.
Note: Parameters such as starting heating intensity, starting intensity, heating time, and cooling time are the manufacturer’s recommendations and they will be included in the specifications within the welding workbench.
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