Why does the construction wastewater system use ductile iron pipes instead of galvanized steel tubes?
The cost is low, the construction cost is low, and the schedule is fast. Such as PVC, PE double wall corrugated pipes, etc..
The sewerage system uses ductile iron pipes. The premise should be pressure pipe drainage. It must be a special occasion, otherwise the cost will be high. In general, precast concrete pipes are recommended.
Then answer your question: first, the strength of ductile iron is much higher than that of ordinary low carbon steel, such as Q235. Corrosion resistance is much higher than that of ordinary steel pipe and the cost is lower than that of ordinary steel pipe. Second, large diameter steel pipe can only be made of spiral welded pipe, seamless steel pipe is particularly expensive, will not be used. The welded pipe is welded, easy to corrosion water leakage. Third, galvanizing is also a life and very expensive, the pipe has a fluid will wear on the inner wall, zinc plating is meaningless. Galvanized pipe is generally used as a water supply pipe, large caliber water pipes, such as more than 250, and now do not use steel pipes, mostly plastic pipes
