Can hot water pipes be used for pe pipes?

many people will be torn when decorating or renovating waterways: "Can the PE pipe at home be connected to hot water?" In fact, there is no absolute answer to this question - the key depends on what kind of PE pipe you use and how to use it. Today we will start with the characteristics of PE pipe and explain whether "PE pipe can be used as a hot water pipe".

First of all, it must be clear: PE pipe is the abbreviation of "polyethylene pipe". Its advantages are corrosion resistance, good toughness and easy installation, but the core shortcoming is limited heat resistance. The "thermal deformation temperature" of ordinary PE pipes (such as common PE80, PE100) is about 40-60 ° C - simply put, when the water temperature exceeds 50 ° C for a long time, the pipe will gradually become soft and deformed, and the interface is easy to loosen and leak; if the water temperature reaches more than 60 ° C, the pipe wall may even bulge and crack.

Why is this the case? Because the molecular structure of polyethylene is afraid of heat. Long-term contact with hot water will accelerate the "thermal aging" of PE pipes: the molecular chain breaks, the strength and toughness of the pipe decrease, and the originally firm hot melt interface will also become loose due to thermal expansion and contraction. For example, if you use an ordinary PE pipe to connect the hot water outlet of the water heater, you may find that the pipe in the wall leaks within a year, or the water flowing out of the faucet has a "plastic smell" - this is actually a harmful substance released after the pipe ages, which affects the safety of water quality.

Does that mean that all PE pipes cannot be used as hot water pipes? Of course not. There is a "heat-resistant polyethylene pipe" (PE-RT for short), which specifically solves the heat resistance problem of ordinary PE pipes. PE-RT increases the long-term use temperature to 70 ° C by changing the molecular structure of polyethylene, and can even withstand 95 ° C hot water in the short term (such as the high temperature when the water heater starts). This kind of pipe not only retains the advantages of PE pipe, but also meets the needs of household hot water pipes (such as bathrooms and kitchens). It is the mainstream choice of PE pipe for hot water at present.

How to choose the right PE pipe for hot water? Remember these 3 points:

1. Look at the logo: there must be "PE-RT" or "heat-resistant polyethylene" on the pipe wall, and at the same time mark "long-term use temperature 70 ° C";

2. Choose regular products: choose the brand with the test report (note: the specific brand is not mentioned here), and ensure that the material meets the GB/T 28799-2012 "Heat-resistant polyethylene for hot and cold water (PE-RT) piping system" standard;

3. Do not use over-temperature: Even PE-RT pipes cannot be used in hot water environments above 80 ° C for a long time (such as high-temperature water connected to boilers), otherwise they will also accelerate aging.

There are still some details to pay attention to: for example, when installing PE-RT hot water pipes, you must use a special hot melt welder to ensure that the interface is firmly welded; the pipes buried in the wall should be covered with a thermal insulation layer to reduce heat loss and temperature fluctuations; Regularly check whether the nozzle has water seepage and whether the pipe wall is deformed - if you find that there are "wrinkles" or "bulges" on the surface of the pipe, replace it quickly, and don't wait for water to leak before repairing.

To summarize: ordinary PE pipes cannot be used as hot water pipes, and there will be water leakage and safety hazards; PE-RT heat-resistant polyethylene pipes can be used as hot water pipes, but you must choose the right product and install it In fact, the logic of choosing a hot water pipe is very simple: first see "whether it can withstand the temperature", and then see "whether it will age" - after all, the waterway is a hidden project, and choosing the right one at a time can save a lot of trouble.

Finally, a reminder: If you are not sure whether the PE pipe at home can be connected to hot water, it is best to look at the logo on the pipe first, or find a professional plumber to check for you - don't use the wrong pipe to save some money and leave hidden dangers in the future.