Polypropylene pipes and polyethylene pipes have made great progress since China explicitly avoided using galvanized pipes as water supply pipes in new houses in 2000. Among them, PP-R pipe is the third generation of modified PP pipe developed in Europe in the early 1990s. The long-time hot water static pressure life of PP pipe is much longer than that of pp-h and PP-B, and the pressure resistance, low temperature resistance and service life are improved. With the rapid development of China's economy, the consumption of PP-R pipes has also increased significantly, and the market share has increased rapidly. China's Ministry of construction has taken PP-R pipe as the first of the three new plastic pipes, so it has developed rapidly in recent years. In 1997, there were only a few PP-R pipe manufacturers in China, no more than 10 in 1998 and 30 in 1999. By the end of 2000, it is estimated that there are about 70 PP-R pipe manufacturers, with more than 130 production lines, production capacity of more than 50000 tons and theoretical production capacity of less than 20000 tons. Due to the blind launch of PP pipe production enterprises, there is a serious surplus of pipe talents, which leads to vicious competition, quality decline and many problems, which constitutes a very bad social impact. In the past two years, through the national rectification and the introduction of corresponding pipe quality and construction standards, the industry was embarking on the road of healthy development. At that time, the domestic production capacity was about 300000 tons and the output was about 140000 tons.