The advantages and characteristics of PE pipe are as follows:
1. Excellent physical properties.
Medium-density polyethylene (MDPE) has properties intermediate between high- and low-density polyethylene (HDPE). It maintains the rigidity and strength of HDPE while also offering excellent flexibility and creep resistance. Furthermore, HDPE offers excellent hot-melt connection properties, facilitating the installation of plastic pipes.
2. Corrosion resistance and long service life.
In coastal areas of my country, where groundwater levels are high and soil humidity is high, seamless steel pipe requires corrosion protection and installation with externally honed grooves. This results in a lifespan of only 30 years. PE pipe, on the other hand, is resistant to corrosion from a wide range of chemicals and requires no corrosion protection. Furthermore, it does not promote the growth of algae, bacteria, or fungi, and has a service life of up to 50 years.
3. Excellent toughness and flexibility.
PE pipe is a highly tough material with an elongation at break exceeding 500%. It is highly adaptable to uneven foundation settlement and misalignment and offers excellent seismic resistance. Therefore, it is ideally suited for use in earthquake-prone areas. Worldwide, PE pipe has proven to be the most earthquake-resistant pipe. It is said that during the 1995 Kobe earthquake in Japan, PE pipe and water supply pipes were the only pipes undamaged. Furthermore, PE pipe's flexibility allows it to be coiled, reducing the number of connecting fittings. The routing of PE pipe can be easily adjusted to suit the construction method. During installation, obstacles can be bypassed within the pipe's permitted bending radius, reducing construction complexity.
4. High flow capacity and economical efficiency.
The inner surface of PE pipe is smooth and scale-resistant. The equivalent absolute roughness ratio of the inner surface of PE pipe is 1/20 that of steel pipe. For the same diameter, length, and pressure, PE pipe has a flow capacity approximately 30% greater than that of steel pipe, resulting in a significant economic advantage. Compared to metal pipes, PE pipes can reduce project investment by approximately one-third. Small-diameter pipes that can be coiled further reduce project costs.
5. Convenient connection, simple construction, and diverse methods.
PE pipes are lightweight, easy to transport, and weld easily, with fewer weld joints. For long pipelines, coiled pipe can be used. PE trench requirements are much lower than those for steel pipes. Furthermore, when construction conditions are limited, electric fusion welding can be used. Furthermore, pipes can be laid underwater by submerging them, significantly reducing construction difficulty and project costs.
6. Excellent sealing.
PE pipes are welded, essentially ensuring the consistency of the joint material and structure with the pipe itself, achieving integration between the joint and the pipe. The joint's tensile and burst strengths are higher than those of the pipe itself, effectively resisting the hoop and axial stresses generated by internal pressure. Therefore, compared to rubber ring joints or other mechanical joints, there is no risk of leakage due to joint distortion, and the sealing performance is excellent.
7. Easy maintenance.
Repairs and installations can be performed without shutting off water or gas.
8. Excellent resistance to stress cracking.
PE pipe has low notch sensitivity, high shear strength, excellent resistance to scratches, and outstanding resistance to environmental stress.
9. Excellent low-temperature impact resistance.
PE pipe has an extremely low-temperature brittleness temperature and can be safely used in temperatures ranging from -60°C. However, in my northern country, when laying polyethylene buried water supply pipe outdoors in winter, a common practice is to avoid installation in temperatures below freezing, as polyethylene pipes are prone to brittle cracking.
10. Excellent wear resistance.
A comparative wear resistance test between polyethylene pipe and steel pipe showed that polyethylene pipe is four times more wear-resistant than steel pipe.
11. Excellent resistance to 222 scratches.
Research has confirmed that PE pipes with high PE grades have excellent resistance to SCG and scratches. PE100 grade pipes have even better scratch resistance.
12. Excellent resistance to rapid crack propagation.
Cracking occurs when cracks propagate rapidly in a pipe, potentially causing damage in an instant, with devastating consequences. Practice has shown that PE pipe, among plastic pipes, has a stronger resistance to crack propagation than other pipes.