Properties: 1.Sanitary and innoxious: no breeding algae or microbe, no second pollution to water; 2.Smooth inner wall: less friction, larger water passage capacity; 3.Light weitht:1/5 of cast iron pipe, easy to transport and construct; 4.Easy to install: to connect with adhesive or elasticity airproof rubber-ring, safe and fast; 4.Strong mechanic intension: resistant to press and impact, applicable to various pipe work; 5.Long service life: up to 50 years in common conditions. Application area: drainage for construction system