PE pipes are commonly used in construction projects, mainly used in water supply and drainage projects. Here we will learn about the performance parameters of PE pipes:
1、 What is PE100 polyethylene pipe?
It is recognized that the development of polyethylene pipe materials can be divided into three generations, namely three development stages:
For the first generation, low-density polyethylene and "Type I" high-density polyethylene have poor performance, which is equivalent to the current polyethylene pipe materials below PE63.
The second generation, which appeared in the 1960s, is a medium density polyethylene pipe material with high long-term hydrostatic strength and crack resistance and super wear-resistant composite plate, which is now called PE80 grade polyethylene pipe material.
The third generation, which appeared in the 1980s, is called the third generation polyethylene pipe material PE100. PE100 means that the polyethylene pipe can still maintain 10MPa low required strength MRS after 50 years at 20 ℃, and has excellent resistance to rapid crack growth. At present, there is no domestic material of this generation.
2、 Mechanical properties of PE100 resin (Solvay ELTEX TVB120 series)
3.1 Durable strength
The endurance strength is determined by testing the pipeline pressure at different temperatures (20 ℃, 40 ℃, 60 ℃ and 80 ℃). At 20 ℃, PE100 resin can maintain low strength of 10MPa after 50 years (PE80 is 8.0MPa).
3.2 Good resistance to stress cracking
PE100 special material for polyethylene pipes has good resistance to stress cracking, which delays the occurrence of stress cracking (>10000 hours) and can even be delayed to more than 100 years at 20 ℃.
3.3 Significant anti crack rapid growth capability
The requirement of anti crack rapid growth capability limits the use of traditional polyethylene pipes: in terms of gas, the pressure limit is 0.4MPa, and in terms of water delivery, 1.0MPa. Due to the remarkable anti crack rapid growth ability shown by PE100, the pressure limit in the natural gas network is increased to 1.0MPa for the ultra wear-resistant composite plate (1.2MPa has been used in Russia, and 1.6MPa has been used in the water transmission network). In a word, the application of PE100 polyethylene material in the pipeline will ensure a safer, more economical and longer service life of the pipe network.
3、 What are the main advantages of PE100 polyethylene pipe?
PE100 has all the excellent properties of polyethylene, and its mechanical properties are significantly improved, which makes PE100 have many special advantages and is used in more fields.
2.1 Stronger pressure resistance
Since PE100 resin has a small required strength of 10MPa, which is much stronger than other polyethylene in pressure resistance, gas and liquid can be transported under high pressure;
Polyethylene pipe series gas water
PE80 SDR17/SDR17.6 0．2MPa 0．8MPa
SDR11 0.4MPa 1.25MPa
PE100 SDR! 7/SDR! 7.6 0.4MPa 1.0MPa
SDR11 1.0MPa 1.6MPa
Therefore, for a given diameter, the increase of pressure will significantly enhance the conveying capacity of the pipe; For natural gas pipelines, increasing pressure and reducing pipe diameter can be selected at the same time, so that the total cost will be reduced accordingly. Because: ① can save pipes; ② Narrow trench can be dug to install pipes; ③ The pipe can be smaller to facilitate winding and reduce connection (welding) joints; ④ The pipeline becomes smaller, and other installation technologies can be selected.
2.2 Thinner pipe wall
Under the normal operating pressure, the pipe made of PE100 material is used for the super wear-resistant composite plate, and its pipe wall can be greatly thinner. For large-diameter water delivery pipes, the use of thin wall pipes can save materials and expand the area of the cross section of the pipe, which increases the transportation capacity of pipes. If the conveying capacity is constant, the increase of the cross section will reduce the flow rate, which can be realized by using a smaller pump, thus saving costs.
Table 2: Use PE100 to reduce the wall thickness of water pipes and gas pipelines Operating pressure PE80 PE100 saves materials Cross section increases Delivery capacity increases
Water: 1.0Mpa SDR11 SDR17 33% 16% 35%
Water: ≤ 0.4Mpa SDR11SDR17.6 35% 17% 24%
2.3 Higher safety factor
If the pipe size is determined or the operating pressure is specified, PE100 can ensure a high safety factor in today's various polyethylene pipe series.
2.4 Higher hardness
PE100 material has an elastic modulus of 1250MPa, which is higher than 950MPa of standard high-density polyethylene resin, which makes PE100 pipe have higher ring stiffness.
