In recent years, the development of PE pipes has been v […]
In recent years, the development of PE pipes has been very rapid. The key reasons why PE pipes exceed UPVC pipes are:
1. Polyethylene (PE) raw materials for pipes continue to achieve significant development: In the early stages of the development of plastic pipes, the use of polyethylene (PE) pipes was far lower than that of polyvinyl chloride (PVC) pipes. The key reason was economic efficiency. At that time, high-performance polyethylene pipe raw materials were not developed and designed. Only polyethylene raw materials equivalent to PE63 were used. Because of the low strength, the PE pipe wall was twice as thick as UPVC pipe under the same standard. Not only the cost of raw materials is high, but also it can only be used on pipes with lower working pressure and smaller diameter, otherwise the wall thickness is too thick to be applied. However, because of the development and design of special materials for polyethylene pipes, a new generation of high-strength raw materials emerge in endlessly. Not only PE80 products, but also PE100 products. With the upgrading of polyethylene raw materials, the various stresses of polyethylene pipes have increased a lot, and the thickness of polyethylene has become thinner and thinner, even exceeding that of PVC pipes. In this way, the advantage of PVC with thinner wall thickness and low cost has long been lost.
The unique flexibility and weldability of polyethylene pipes facilitate the laying of pipelines and economic development, the application is more reliable, and the main purpose is also improved. From the cost point of view, high-grade polyethylene pipe special materials are higher than PVC pipe raw materials. However, why are there still many applications in developed countries? It is because pipes made of high-performance polyethylene raw materials have many unique advantages. One is the distinctive flexibility of PE pipes. Its elongation at break is above 500, and its bending radius can be as small as 20-25 times the pipe diameter. It also has high-quality scratch resistance.
Therefore, it is very easy to move, bend and penetrate during laying. Polyethylene pipes have low requirements for pipe trenches, not only can the cost of pipe trenches be reduced, but at the same time, when the foundation causes uneven settlement and displacement, the pipes are not easily destroyed. In addition, PE pipes can be connected with more convenient heat-fusion, and heat shrinkable tapes can also be used on large-diameter pipes.
Low-temperature toughness: The superior characteristics of polyethylene pipes than PVC pipes are manifested in low-temperature toughness. Usually, the winter temperature in North China, Northeast, and Northwest China is minus 0℃---30℃. At this time, the PVC pipe will become hard and brittle, it is very easy to be destroyed, but the PE pipe still maintains its excellent flexibility, even at -30℃, it will not become brittle.
Aging resistance: Polyethylene pipes are now prescribed to be blue or black, especially when 2% carbon black is added to avoid damage from light and ultraviolet rays, while PVC pipes are still yellow and white and cannot be exposed to the sun for a long time.
Working pressure of environmental protection: PE pipes are harmless to humans and the natural environment, while PVC pipes use heavy metal salts as stabilizers to cause heavy metal pollution to the water quality and the soil layer buried in the pipes, such as incineration when recycling old waste pipes It can cause harmful substances such as dioxins.