PVC-U pipes and UPVC pipes are the same type of pipe, namely rigid polyvinyl chloride pipes. The U stands for Unplasticized, indicating that it has higher strength or hardness than ordinary PVC. PVC-U pipes were initially used as water pipes to replace galvanized steel pipes, but due to their troublesome maintenance, lack of toughness, brittleness at temperatures below 5°C, softening above 45°C, and the leaching of UPVC monomers and additives during long-term use, they are less favored.

　　Currently, PVC-U pipes are mainly used for drainage pipes. While outdoor water supply design specifications mention that PVC-U pipes can be used for water supply pipes, they are no longer used in actual water supply pipeline projects. PPR pipes and PE pipes are more commonly used for water supply pipes.

　　PVC-U drainage pipes have high impact resistance. Their ring stiffness is 8 times that of ordinary PVC-U. According to test results, their impact resistance is 2-4 times that of solid-wall PVC-U pipes (***standard). This effectively reduces accidental damage to pipes during construction. Due to the use of nanotechnology, the wear resistance of the pipes is greatly improved, reaching 4-7 times that of ordinary polyvinyl chloride pipes, significantly increasing the service life of the pipes to over 50 years.

　　The special composite multilayer structure of PVC-U drainage pipes greatly improves their sound insulation performance. The composite multilayer structure effectively blocks the transmission of noise. The smooth inner wall and low friction coefficient improve fluid transport efficiency and reduce noise, making them suitable for drainage systems in high-rise buildings. At the same time, PVC-U drainage pipes have excellent heat insulation properties, with thermal conductivity 35% lower than that of ordinary solid-wall pipes. Therefore, they have a wide operating temperature range, do not condense on the surface, and can save insulation costs when used for the insulation and transportation of cold and hot fluids.