Current Situation And Existing Problems Of PVC Tube And PSP Tube
The PVC pipe has been used for more than 60 years in urban water supply abroad. Since the 80s last century, China has been widely popularized by the relevant state departments in planning, step and organization. The advantages of PVC pipe have gradually been recognized by the users of the general water company and gradually applied. Up to now, PVC pipe is still the most perfect pipe variety in the water supply pipeline, which has the largest amount, the longest history, the most mature technology, the most complete matching, the product standard, the test method, the construction technology and the maintenance method. Another kind of material used for water supply, polyethylene pipe with the progress of polyethylene material, its application in the field of water supply is increasing gradually. The total growth rate of polyethylene pipe in various applications abroad is about 7~8%. In recent years, because of the progress in raw materials, processing equipment, standardization of products and the promotion of national policy, PSP pipes have developed rapidly in China. But we can not fail to see that the factors restricting the normal development of PSP pipeline in China are difficult to solve in the near future.
(1) the problem of raw materials:
According to ISO standard, European standard and national standard, polyethylene pipe must be mixed. There are no strict PSP80 or PSP100 mix ingredients in China. The mixed mix price of imported PSP80 and PSP100 is high, so most enterprises adopt "white + black" to produce PSP pressure pipe. More serious is to reduce the cost of some enterprises, the addition of black mother is not only small, but also the dispersivity is poor and the particle size can not reach the requirement. This product is not only weatherproof but also will affect the long-term product. Safe service life.
(two) connection problem
The connection technology of PSP pipeline and pipeline element is the key to ensure the quality of water supply engineering. The rapid development of European PSP pipeline is closely related to the progress of its raw materials and processing equipment, and the continuous improvement of connection equipment and connection technology. All of its construction personnel are trained by relevant institutions and obtained certificates of rank before they can be employed and can be traceable. However, the quality of construction teams in China is relatively low, the quality of welded joints is poor, and the strength of interfaces is smaller than the strength of the main body, so the long service life of the pipeline system can not be guaranteed.
(three) maintenance of pipeline system
The application of PSP pipeline in China is not long. There are many problems in pipe fittings, both in pipe fittings and in pipeline maintenance. Because of the characteristics of the material itself, the maintenance pipe and maintenance method of the PVC-M pipeline system can not be copied to the PSP pipe, and to a certain extent, it restricts the popularization and application of the PSP pipe in the field of water supply.
In a comprehensive analysis, the two materials have their advantages and disadvantages. The PVC channel is used in water supply not only with a long history, mature technology, perfect matching, convenient for construction and maintenance, but also greatly reduced the cost of the project compared with the cast iron pipe and the PSP pipe. However, due to its low temperature tolerance, protective measures should be taken in cold weather construction to prevent quality problems caused by collisions. The qualified PSP pipeline has excellent low temperature resistance and good toughness. It has strong adaptability to tube base and suitable for low temperature environment and relatively complex geological conditions. It is especially suitable for non excavation construction. But the application of PSP pipeline to water supply project is not only slow in installation speed, high in comprehensive cost of engineering, and strict in technical quality of construction team. But because of its short application time in China, the pipe fittings and pipeline maintenance still need to be further improved. As a water supply unit, it should be considered in terms of engineering geological conditions, material characteristics, engineering cost, construction time requirements, piping system supporting, installation, maintenance and other factors. Finally, the pipe material that can meet the needs of the project is determined.