PE pipe (polyethylene material) and PPR pipe (random copolymer polypropylene material) are plastic pipes used at high frequencies in home improvement and engineering, but the molecular structures of the two are different. If they are directly connected by hot melt or electrofusion, there will be problems of weak fusion and easy leakage. To achieve a reliable connection, the key is to bridge the two materials through a "transition tool". The following will give you a detailed introduction to 3 common methods and operation points.
The most commonly used method is the adapter joint method, which is also the most recommended method in home decoration. The adapter joint is a "two-way interface" specially designed for pipes of different materials - one end is PE material (matching the hot melt parameters of PE pipe), and the other end is PPR material (matching the hot melt requirements of PPR pipe). The operation steps are very simple: first select the corresponding specification of the adapter (such as PE110 to PPR110) according to the diameter of the PE pipe and the PPR pipe; then use a PE hot melt machine to heat the PE pipe end and the PE end of the adapter (the temperature is about 220 ° C). After a uniform melting layer appears on the surface of the pipe, quickly connect and keep it fixed for 3-5 seconds; then use a PPR hot melt machine to heat the PPR pipe end and the PPR end of the adapter (the temperature is about 260 ° C), and also connect and cool; finally check whether the joint is flat and has no warping edge. This method has a low operating threshold and good sealing performance, which is suitable for most conventional scenarios.
If it is a large-diameter pipe (above DN100) or a high-pressure scene (such as a water supply main pipe), it is recommended to use the flange connection method. First install a PE flange to the PE pipe (fixed at the end of the pipe by hot melt or electrofusion), and install a PPR flange to the PPR pipe (fixed by welding with a PPR hot melt machine); Then put a sealing gasket for the suitable medium between the two flanges (choose food-grade rubber gasket for drinking water, and oil-resistant rubber gasket for industrial use); Finally, tighten evenly along the circumference of the flange with bolts to ensure that the sealing gasket is compacted and there is no gap. The advantages of flange connection are easy disassembly and strong pressure resistance, but the cost is slightly higher, which is suitable for engineering scenarios that require frequent maintenance or high pressure.
small-diameter pipe (DN20-DN50) or temporary connection, you can choose the thread connection method. First install a PE threaded joint for the PE pipe (fixed by hot melt), and install a PPR threaded joint for the PPR pipe (also fixed by hot melt); then wrap 3-5 turns of raw material tape (or liquid raw material tape) clockwise on the threaded joint to fill the thread gap; finally align the two threaded joints and tighten them clockwise until they feel difficult (be careful not to use too much force to avoid cracking of the joint). The advantage of this method is that it is fast to operate, but the threads are prone to water leakage due to aging, which is not suitable for long-term or high-pressure use.
There are several key considerations in the connection process: First, the specifications must match, and the pipe diameter of the adapter, flange or threaded joint should be exactly the same as the pipe. For example, if the PE pipe is DN50, choose the DN50 joint; second, keep it clean, and wipe the dust and oil at the pipe end before welding or connecting to avoid impurities affecting the connection strength; third, control the temperature. The PE end and PPR end of the hot-melt adapter should be adjusted separately. If the temperature is too high, it will cause the pipe to deform. If it is too low, the fusion will not be strong. Fourth, test the sealing. After the connection is completed, a water pressure test must be done (using 1.5 times the work stress testing for 30 minutes) to ensure that there is no water leakage or leakage.
In fact, the connection between PE pipe and PPR pipe is not complicated. As long as the appropriate transition method is selected and the operation details are paid attention to, the docking problem of different materials pipes can be solved. Whether it is the water pipe transformation in home improvement or the pipeline splicing in the project, the right method can be selected according to the scene to achieve a safe and reliable connection.