In drinking water, PE is generally used as a cold water pipe; PP-R (special hot water material) can be used as a hot water pipe; PP-R (cold water material) can also be used as a cold water pipe; if it is a hot water pipe, of course, PP -R is good; (if it is a drinking water pipe in home decoration, there is no need to distinguish it, basically more PP-R is used than PE) If it is a cold water pipe, you can refer to the following differences:

1. Comparison of temperature resistance between PP-R water pipes and PE water pipes

Under normal use, the PE water pipeline production line has a stable temperature of 70°C and a lower temperature of -30°C. That is to say, within such a temperature range, it is safe and reliable to use PE water pipes for a long time. Under normal use, the stable temperature of PP-R water pipeline is 70°C, and the lower temperature is -10°C. It also shows that within such a temperature range, long-term use of PP-R water pipeline is also safe and reliable. It is concluded that the PE water pipe has the same high temperature resistance performance as the PP-R water pipe. However, PE water pipe is better than PP-R water pipe in low temperature performance.

Second, the difference between PE water pipe and PP-R water pipe in terms of hygiene

The main chemical molecular component of PE water pipe is polyethylene. The composition of this product is two carbon atoms combined with five hydrogen atoms, one of which is combined with carbon atoms by double bonds, and then the single molecule of ethylene is polymerized in a certain way. , such a product is a polyethylene product. So what is PP-R water pipe? The main component of PP-R water pipe is propylene, that is, three carbon atoms are combined with seven hydrogen atoms, and one hydrogen atom is also combined with carbon atoms by double bond, and then the product formed by polymerization is polypropylene product. Such products are almost the same in terms of hygiene and safety. The important thing is whether the raw materials used by the enterprise meet the requirements, not the difference between the two products. It is also unfounded to advertise that PE water pipes are more hygienic than PP-R water pipes in newspapers. All qualified PE water pipes and PP-R water pipe products must undergo sanitary inspection (except those fake and shoddy products). It is also a deception for consumers to say that PE water pipes are more hygienic and safer than PP-R water pipes.

3. Modulus of elasticity

The elastic modulus of PP-R water pipe is 850MPa, and the PE water pipe belongs to medium density polyethylene. The elastic modulus is only about 550MPa. It has good flexibility and insufficient stiffness. It is used in the field of water supply for buildings. The straightness of the pipe is not good, and it is easy to bend and deform. , the pipeline is not beautiful. Thermal conductivity: PP-R water pipe is 0.24, PE water pipe is 0.42, which is nearly twice as high. If it is used in floor heating, this is its strength. Good heat dissipation means better heat radiation effect, but it is used in hot water pipes. The disadvantage is that the heat dissipation is good, the heat loss is large, the surface temperature of the pipe is also higher, and it is easy to be hot.

4. Weldability

Although both PP-R water pipes and PE water pipes can be hot-melt welded, PP-R water pipes are easier to operate. R water pipe is 260℃, PE water pipe is 230℃, and the special welding machine for PP-R water pipe on the market is easy to over-weld and cause water leakage. In addition, because the PE water pipe material is easy to oxidize, special tools must be used to scrape off the oxide skin on the surface before welding, otherwise a truly integrated pipeline cannot be formed, and the pipeline is easy to leak, so the construction is more troublesome.

5. Low temperature impact strength

In terms of indicators, this is the strength of PE water pipe materials. PP-R water pipes are stronger than PE water pipes, and PE water pipes are more flexible than PP-R water pipes. This is determined by the nature of the material, but the cold brittleness of PP-R water pipes is exaggerated. The problem is meaningless. PP-R water pipes have been used in China for more than ten years. Manufacturers have gradually reduced the hidden dangers caused by improper handling to a lower level through effective packaging and strengthened publicity. The same as construction will cause surface scratches and stress cracking of PE water pipes; any pipes must be insulated when used under low temperature conditions, otherwise the pipes will freeze and crack due to volume expansion caused by icing.

6. The size of the PE pipe can be large, the larger size is dn1000, and the larger size of the PP-R is dn160. Therefore, the PE pipe is mostly used as a drain pipe, and the water supply pipe is generally PP-R.