1、 Comparison of temperature resistance between PPR water pipe and PE water pipe
Under normal use, the maximum stable temperature of PE water pipeline is 70 ℃, and the minimum temperature is – 30 ℃. In other words, in such a temperature range, long-term use of PE water pipes is safe and reliable.
Under normal use, the maximum stable temperature of PPR water pipeline is 70 ℃, and the minimum temperature is – 10 ℃. It also shows that the long-term use of PPR water pipeline is safe and reliable within such temperature range. It is concluded that PE water pipe and PPR water pipe have the same high temperature resistance. But PE water pipe is better than PPR water pipe in low temperature performance.
2、 Difference between PE water pipe and PPR water pipe in sanitation
The main chemical molecular component of PE water pipe is polyethylene. Readers who have studied organic chemistry know that the composition of this product is the combination of two carbon atoms and 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 polyethylene. So what is PPR water pipe? The main component of PPR 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 bonds. The product formed by polymerization is polypropylene product. Such products are almost the same in terms of health and safety. The important thing is whether the raw materials used by the enterprise meet the requirements, not whether the two products are different. It is also groundless to publicize in newspapers that PE water pipes are more sanitary than PPR water pipes. All qualified PE water pipes and PPR water pipes must pass the sanitary test (except those fake and shoddy products). Saying that PE water pipes are more sanitary and safe than PPR water pipes is also a deception to consumers.
PPR water pipe
3、 Elastic modulus
PPR water pipe has an elastic modulus of 850mpa, and PE water pipe belongs to medium density polyethylene, with an elastic modulus of only about 550MPa. It has good flexibility and insufficient rigidity. It is used in the field of building water supply, with poor straightness, easy to bend and deform, and the pipeline is not beautiful.
Thermal conductivity: PPR water pipe is 0.24 and PE water pipe is 0.42, which is nearly twice as high. If it is used in floor heating, it is its strong point. Good heat dissipation means better heat radiation effect. However, when it is used in hot water pipe, it has its disadvantages: good heat dissipation, large heat loss, higher pipe surface temperature and easy to burn.
4、 Weldability
Although PPR water pipes and PE water pipes can be hot-melt welded, PPR water pipes are easier to operate, and PPR water pipes have round flanging, while PE water pipes have irregular flanging, which is easy to block; The welding temperature is also different. The PPR water pipe is 260 ℃, and the PE water pipe is 230 ℃. The special welding machine for PPR water pipe on the market is easy to over weld and cause water leakage. In addition, because PE water pipe material is easy to oxidize, special tools must be used to scrape off the oxide scale on the surface before welding, otherwise it cannot form a truly integrated pipe, and the pipe is easy to leak, so the construction is more troublesome.
5、 Low temperature impact strength
This is the strength of PE water pipe materials in terms of indicators. PPR water pipe is stronger than PE water pipe, and PE water pipe is more flexible than PPR water pipe, which is determined by the nature of the material. However, it is meaningless to overstate the cold brittleness of PPR water pipe. PPR water pipe has been used in China for more than ten years. The production enterprises have gradually reduced the hidden dangers caused by improper handling to the minimum through effective packaging and intensive publicity, Rough handling and construction will also cause surface scratches and stress cracking of PE water pipes; When used under low temperature, any pipeline must be insulated, otherwise it will be frozen and cracked due to volume expansion caused by ice.
6、 Pipe size
The maximum size of PE pipes is DN1000, and the maximum size of PPR is dn160. Therefore, PE pipes are often used as drainage pipes, and water supply pipes are generally PPR pipes.