Plastic pipes and pipelines are one of the most important infrastructure in cities, and they are closely related to the lives of the people. It is widely used in various liquid and gas transmission pipelines, such as urban drainage pipes, water supply pipes, liquefied gas and natural gas transmission pipes, indoor heating pipes and threading pipes, etc. If the quality of plastic pipes and pipelines is not up to standard, it will bring great inconvenience to the normal operation of the city. For example, if the urban water supply pipeline is damaged, it will be partially flooded, which will have a certain impact on the water supply safety of the people. 1、 Plastic pipes and metal pipes: comparative advantages and disadvantages? Advantage 1: Lightweight, plastic pipes weigh only 1/8 of cast iron pipes; 2. Chemical resistance and good corrosion resistance; 3. Good electrical insulation performance; 4. Low production costs and cheaper prices; 5. The interception of length is more convenient, bringing some convenience to construction. Disadvantage 1: Poor work intensity and lower pressure resistance compared to metal pipes; 2. There are limitations on temperature requirements for use, and the expansion coefficient is much larger than that of metal pipes. 2、 Common products and uses of plastic pipes? Polyvinyl chloride (PVC-U) pipes for building drainage. PVC-U pipes for building drainage are made by using PVC resin as the raw material, adding an appropriate amount of filler and suitable additives, such as stabilizers, modifiers, lubricants, etc., and being extruded by an extruder. Purpose: Polyvinyl chloride (PVC-U) pipes for building drainage are mainly used in fields such as building drainage, municipal sewage, and rainwater drainage. Polyethylene (PE) pipes for water supply. Polyethylene (PE) pipes are extruded from a mixture of polyethylene (usually polyethylene as the main raw material, with pigments, carbon black, and antioxidants added). The common colors of polyethylene water supply pipes are white, blue, and black, but when laying pipes exposed to sunlight, they must be black, mainly considering their aging resistance. Polyethylene pipes can be widely used in fields such as gas transmission, water supply, sewage discharge, agricultural irrigation, oil fields, mines, and post and telecommunications. Aluminum plastic composite pressure pipe is made of high-density polyethylene sandwiched with aluminum. The coil pipe is easy to transport, can be arbitrarily cut, easy to install, and convenient. However, the accessory material is pure copper, which is expensive. The inner diameter of the copper part is smaller than the inner diameter of the aluminum plastic composite pipe, and the diameter flow rate is small. It is also difficult to install and is prone to water leakage due to thermal expansion and contraction