Excellent surface hardness and tensile strength of pipes, high pipe safety coefficient. 2. Good aging resistance, normal service life of more than 50 years. 3. The pipeline has excellent corrosion resistance to inorganic acid, alkali and salt, and is suitable for industrial sewage discharge and transportation. 4. Small friction coefficient of pipeline, smooth water flow, not easy to block, less maintenance work. 5. The material has high oxygen index and self-extinguishing property. 6. Pipeline small linear expansion coefficient of 0.07 mm / ℃, affected by the temperature deformation is small. The thermal conductivity and elastic modulus are small, and the freezing resistance is better than cast iron drainage pipes. 7. The connection of pipes and fittings can be made by bonding, with simple construction method, convenient operation and high installation efficiency. 8. With good water tightness: the installation of pvc-u pipe has good water tightness no matter it is connected by adhesive or rubber ring.