1. "Look" appearance

The color of good PP-R water pipe is gentle, uniform and free of mottled color. In fact, the quality of PP-R water pipe has nothing to do with the color of PP-R water pipe. According to the national regulations, PP-R water pipe should have good light blocking performance, in this regard, the gray or other light tight performance will be better. PP-R tube is completely opaque, while pseudo PP-R tube is slightly or semi transparent. Generally, white products can only be produced with pure PP-R raw materials, and the internal and external surfaces of products shall be smooth and flat, without bubble, obvious depression, groove, impurity and other defects.

2. "Touch" texture

Good PP-R water pipe is 100% PP-R raw material (without any additives) with pure texture, smooth surface, soft hand feeling, and smooth hand feeling of pseudo PP-R pipe. Generally speaking, the rough particles are likely to be mixed with impurities;

3. Smell

PP-R pipe is mainly made of polypropylene. Good pipes have no smell, while bad pipes have strange smell. It is likely that polyethylene is mixed with pipes instead of polypropylene

4. "Pinch" hardness

PP-R tube has a considerable hardness, which can be easily pinched and deformed. It is certainly not PP-R tube;

5. "Measure" wall thickness

In addition, vernier caliper can be used to measure whether the pipe wall thickness is up to standard and uniform. Generally, good pipes are produced strictly according to the national standard, but this method requires a certain understanding of the national standard for PP-R pipes.

6. Listen to the voice

PP-R pipe landing sound is dull, and the pseudo PP-R pipe landing sound is clear and crisp.

7. "Smash" elasticity

A good PP-R pipe has a good "resilience" and it is easy to crush the PP-R pipe which is naturally not good, but the PP-R pipe with the temperature lower than 10 ℃ can also be crushed. But the hardness is not equal to the elasticity. Some manufacturers increase the hardness by adding too many impurities such as calcium carbonate, which can not be broken, and it is easy to crack after long use. (because the cold brittleness of PP-R raw materials has different properties in several temperature ranges: 10, - 5, - 23...)

8. "Burn" smoke and smell

PP-R pipes mixed with recycled plastics and other impurities in raw materials will emit black smoke and have a pungent smell. The good material will not only not emit black smoke and no smell after burning, the molten liquid is still very clean after burning. (you can also "pull" to see its pull "length")

9. "Melting"

When PP-R pipeline is welded, the normal welding temperature is in the range of 260-290 ℃, and the welding quality will be better guaranteed in this temperature range. If under the normal welding parameters, the product can easily enter the welding die head when welding, and the welding accumulation tumor is close to the liquid state, which indicates that the product is not produced by the authentic PP-R raw material, and the fusion accumulation tumor can quickly cool down Hard (usually within 10 seconds) can also show that the product is not produced from authentic PP-R raw materials. This is because one of the characteristics of PP-R is that it has good heat preservation effect and its cooling speed will naturally be slow. Check whether the inner diameter of the pipe is deformed and whether the pipe fittings are drawn. Good PP-R pipes are not allowed to be drawn and the inner diameter is not easy to be deformed.

10. "Inspection"

Using test instruments to test can effectively distinguish the advantages and disadvantages of products. Several important test data are specified in the national standard, such as pipe anti-aging test (the test of keeping 8760 hours at 1.9mpa ring stress and 110 ℃ test temperature), pipeline system stability test (5000 cold and hot cycles) and impact resistance test, etc. Therefore, the user can require the manufacturer or merchant to provide the above test report for verification when selecting 。 In addition, the national standard also has an important requirement for the raw materials used for pipes and pipe fittings, which is the melt index. The national standard requires that the change value of the melt index before and after processing shall not exceed 30%, and there is also a requirement in the industry that the melt index of raw materials shall not exceed 0.5g/10min.