Hollow wall winding pipe made by this product line has high ring stiffness and high brunt intensity due to unique structure(see the picture on the right). It can be used for over 50 years and has many advantages such as light weight, easy operation, facile installation, withstanding pressure, corrosion resistant such as acid, alkali and salt etc. It is replacing cement pipe, cast iron pipe and ceramic pipe in city drainage, sewage treatment, highway and railway drainage, agricultural irrigation etc. This product has a good prospect in application and enjoys a potential market. Production line features: The extrusion line is designed with advanced design and screw forming technique. Tubing it makes has high production efficiency, stable operation, high ring stiffness, and excellent creep resisting property. High efficiency extruder specially designed by our company guarantees large output and fine plasticizing. The whole product line uitlizes PLC and man-machine interface control of contact screen, which enables facile operation, stable production and high finished product rate