company news about Winter temperature drops, PPR water pipe installation precautions

In the after-sales accident of PPR water pipes, there are not many cases of water pipes bursting, and most of them are caused by leakage of some solder joints. When winter comes and the temperature drops, we especially need to pay attention to the characteristics of PPR water pipes becoming brittle at low temperature, which is the main culprit for the leakage of many solder joints. Today we will introduce the low temperature brittleness of PPR water pipes in detail, and how we should operate correctly to deal with this problem.

1. What is the low temperature brittleness of PPR water pipes?

The low temperature brittleness of PPR water pipes refers to the phenomenon that the rigidity of PPR pipes increases, the flexibility decreases, and the overall water pipes become brittle when the temperature is low in winter.

Due to low temperature brittleness, when the PPR water pipe is impacted by external force, cracking will occur. Also, cracks usually start from the inner tube and extend to the exterior. And this phenomenon is usually more likely to occur at the port of the PPR water pipe.

When the port of the PPR water pipe is cracked, and it is not found in time during welding, it is difficult to find it with the naked eye after the welding is completed, and sometimes it cannot be completely detected by the pressure test, which will leave the water leakage accident of the PPR water pipe in the later stage. There is a great danger.

2. Why does PPR water pipe have low temperature brittleness?

PPR is the abbreviation of Polypropylene Random, which is called random copolymerized polypropylene in Chinese, which is commonly known as tri-type polypropylene. %) by random copolymerization under the action of heating, pressure and catalyst.

Temperature-Deformation Curves of Amorphous Polymers

For polymers, there is a glass transition temperature, and as the name suggests, below this temperature, the polymer becomes brittle like glass. Different polymer products have different glass transition temperatures. The glass transition temperature of PPR is higher than that of ordinary plastics.

In short, the low temperature brittleness of PPR water pipes is an inherent characteristic of its materials. As long as PPR materials are used, this characteristic must be present, and there is no way to change it.

3. Does the low temperature brittleness of PPR water pipes affect its use?

Low temperature brittleness reduces the impact resistance of PPR water pipes, that is, PPR water pipes cannot be subjected to impact such as collisions and beatings. Low temperature brittleness does not affect the stiffness and strength of water pipes, so it does not affect the pressure bearing capacity of water pipes. Therefore, as long as the water pipe is installed, it will not be affected by low temperature brittleness during operation.

How to understand this? We use another material as an analogy, glass is very brittle, its impact resistance is very weak, and it shatters almost when it is dropped, but its stiffness and hardness are very good.

4. How to avoid the harm of low temperature brittleness of PPR pipe?

There are clear requirements in the national standard "GB/T50349-2005". To sum up, the following points need to be paid attention to in the actual installation:

1. It is strictly forbidden to throw, drop, roll, and drag the pipe during the handling process. After dark laying, the position of the pipe should be marked to avoid damage to the pipe by the second decoration;

2. The pipes are stored in the warehouse, and the stacking height shall not exceed 1.5m;

3. Cut the tube slowly with a sharp knife;

4. Before cutting the pipe, avoid using the pipe that causes the stress of the pipe body to become white due to external force;

5. Before hot-melting, carefully check whether the inner wall and port of the pipe are damaged;

6. After the pipeline is installed, the pressure must be tested before direct burial and non-direct burial;

5. What can't be broken is not necessarily a good water pipe

It is a misunderstanding to judge the quality by smashing the water pipe, because what we need for the PPR water pipe is its static pressure strength, not the impact resistance.

Moreover, the PPR water pipe has low temperature brittleness, when the temperature is higher than 5 ℃, the PPR water pipe has good flexibility. But when the temperature is lower than 5 ℃, the PPR water pipe is easier to break, and those water pipes that are not broken just prove that it is not an authentic PPR pipe, which is the problem.

For the low temperature brittleness of PPR pipes, after understanding the principle, consumers and installers should pay attention to prevent the damage of PPR pipes caused by low temperature brittleness and avoid unnecessary losses.