in the installation and maintenance of PE pipes, many people will ask: Can PE pipes be externally hot-melted? The "external hot-melt" here usually refers to the hot-melt connection or repair operation on the outer wall of the PE pipe (rather than the end faces of both ends). Today we will answer this question in detail to help you understand the feasibility, common scenarios and key operation points of the external hot-melt of PE pipes.

PE (polyethylene) is a thermoplastic. It will soften when heated to 21010 ° C. After cooling, it will be re-formed and maintain strength. This characteristic is the basis for various hot-melt operations of PE pipes. Whether it is the butt/socket hot-melt of the end face or the external hot-melt of the outer wall, the essence is to use the thermoplastic of PE to achieve connection or repair.

The answer is yes: PE pipes can be externally hot-melted, but two prerequisites are required - professional tools and standardized operation. If the operation is improper (for example, the temperature is too high to cause the material to decompose, and the pressure is not enough to cause the connection to be weak), it will affect the performance of the pipeline.

There are two most common external hot-melt scenarios: First, branch pipe connection - when branching from the main PE pipe, use a saddle-shaped hot-melt pipe fitting (saddle) to buckle on the outer wall of the main pipe, use a special saddle-shaped hot-melt machine to heat the pipe fittings and the outer wall of the pipe, soften and press and fit, and form a firm branch after cooling; Second, repair the outer wall damage - when there is a small area of damage, use a PE patch of the same material, heat the patch and the damaged part through a hand-held

To do a good job of external hot melt, these points must be paid attention to: 1. Tool specialization: use a saddle-shaped hot melt machine for branches, and a handheld hot melt gun for repair to ensure accurate temperature and pressure; 2. Temperature accuracy: must be controlled at 21010 ° C, too high will cause PE to decompose (pungent smell, material brittleness), and too low will not soften; 3. Surface treatment: clean the outer wall of the pipeline before hot melt (alcohol or dry cloth to wipe off dust and oil stains), if necessary, use sandpaper to polish and increase the bonding area; 4. Control pressure and time: Apply appropriate pressure after heating and softening (adjust according to the diameter), keep it for a few seconds to tens of seconds (see tool instructions), so that the PE can be fully integrated, and the pipe cannot be moved during cooling to avoid misalignment.

also remind a few precautions: ① It can only be used for PE pipes of the same material, and cannot be hot-melted with other plastics such as PVC and PPR (the melting point and expansion coefficient are different, and it is easy to crack); ② It cannot be over-heated - stop immediately when you smell the pungent plastic smell; ③ It must be operated by professionals - it is difficult for non-professionals to control the temperature and pressure, and it is easy to leave a hidden danger of water leakage; ④ Post-mortem detection - use a pressure test pump to test at 1.5 times the design pressure to confirm that there is no water leakage and then use it.

In general, PE pipes can be hot-melted externally, but it is by no means "just pasted". It needs to use the thermoplasticity of PE, and cooperate with professional tools and standardized operations to ensure the quality. If there is a demand, it is recommended to find experienced professionals to avoid problems caused by improper