Nowadays, most flap valves are made of HDPE. What are the advantages of using HDPE when compared with cast iron?
Answer:
Answer:
- It has no reaction with sewage and seawater and does not suffer from the corrosion problem associated with cast iron.
- No protective coating is required and it is almost maintenance-free.
- HDPE flap valves require very low opening pressure in operation (like 5mm water level difference). For cast iron flap valves, due to its own heavy self-weight, the required opening pressure of cast iron flap valves is higher than that of HDPE flap valves. This criterion is essential for dry weather flow conditions.