Ductile iron pipes refer to pipes that are cast by high-speed centrifugal casting in a centrifugal ductile iron casting machine using molten iron above No. 18 and adding a nodulizing agent. It has the essence of iron and the properties of steel, and has excellent anti-corrosion properties and good ductility. Widely used in water supply, drainage, gas and other pipeline systems as well as bridge and road projects, fire protection systems.