The color of a good PP-R water pipe is soft and uniform without mottling. (PP-R pipes mainly include white gray, purple, green, yellow and blue. Consumers often think that white is good, In fact, color is not the standard to judge the quality of PP-R pipes. In fact, the quality of PP-R pipes has nothing to do with the color of PP-R pipes. Plastic particles are mainly white, transparent color (and other colors have been added with color masterbatch). As long as any color of color masterbatch is added, the color masterbatch will not be decomposed and will not change the quality of PP-R pipes, Therefore, it doesn't matter what color the water pipe is. According to national regulations, PP-R water pipes should have good light-tight performance. In this regard, gray or other light-tight performance will be better. However, such advantages only exist in the installation of exposed pipes and pipe wells. All domestic water pipes are concealed, so there is no saying that gray is superior to other colors. The PP-R tube is completely opaque, and the fake PP-R tube is slightly or semi-transparent. Generally, white products can only be produced with pure PP-R raw materials. For example, the color of products produced with recycled materials, waste materials and corner materials is not soft and uniform, while the color of other color products processed with color masterbatch will not be affected by adding recycled materials, waste materials, and corner materials. This is why many manufacturers that focus on quality and mainly on home decoration retail are mainly white); The internal and external surfaces of the product shall be smooth and flat, and free from defects such as bubbles, obvious depressions, grooves and impurities.
"Touch" texture
A good PP-R pipe is 100% PP-R raw material (without any additives) with pure texture, smooth surface, soft hand feel, and a fake PP-R pipe with smooth hand feel. Generally speaking, coarse particles are likely to be mixed with impurities;
Smell
The main material of PP-R pipe is polypropylene. The good pipe has no smell, and the bad pipe has a strange smell. It is likely that polyethylene is mixed instead of polypropylene;
"Pinch" hardness
PP-R pipe has a considerable hardness, so you can easily pinch the deformed pipe, which is certainly not PP-R pipe;
"Quantity" wall thickness
In addition, vernier calipers can be used to measure whether the pipe wall thickness is up to standard and uniform. Generally, good pipes are produced in strict accordance with the national standard, but this method requires a certain understanding of the national standard of PP-R pipes.
Listen
The landing sound of PP-R pipe is dull, and the landing sound of fake PP-R pipe is crisp.
"Smashing" elasticity
A good PP-R pipe has a good "resilience" and is easy to break. Naturally, it is not a good PP-R pipe, but it can be broken even if the temperature is lower than 10 ℃. However, strong hardness is not equal to good elasticity. Some manufacturers increase the hardness by adding too much calcium carbonate and other impurities, which can not be broken. It is easy to crack after being used for a long time; (Because the cold brittleness of PP-R raw material is different in several temperature ranges: 10, - 5, - 23...)
"Burn" smoke 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 emit black smoke and smell after burning, and the molten liquid will still be clean after burning. (You can also "pull" to see its "length")
"Melting"
The normal welding temperature of the PP-R pipeline during welding is in the range of 260-290 ℃, and the welding quality will be better guaranteed during welding in this temperature range. If under the normal welding parameters, the product can easily enter the welding die during welding, and the welding accumulation has been close to liquid, it means that the product is not produced with authentic PP-R raw materials, At the same time, if the weld build-up can be rapidly cooled and hardened (usually within 10 seconds), it can also indicate that the product is not produced with authentic PP-R raw materials. This is because one of the characteristics of PP-R is that the heat preservation effect is good, and its cooling rate 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 deform.
Inspector
Borrow test instruments for testing to effectively distinguish the advantages and disadvantages of products. Several important test requirements data are specified in the national standards, such as the aging resistance test of pipes (the test that can keep the pipes intact for 8760 hours under the ring stress of 1.9MPa and the test temperature of 110 ℃), the stability test of pipe system (5000 cold and hot cycles), and the impact resistance test. Therefore, users can request the manufacturer or merchant to provide the above test reports for verification when selecting. In addition, it should be pointed out that the national standard also has an important requirement for the raw materials used for pipes and pipe fittings, that is, the melt index. The national standard requires that the change value of the melt index before and after processing should not exceed 30%, and there is also a requirement in the industry that the melt index of raw materials should not be greater than 0.5g/10min.