The company's valves are used in water plants. The water supply capacity of the water plant is 0.5 million cubic meters. The water source is taken from Rongjiang. There are various materials to meet the requirements for the use of valve housings for water supply and drainage. However, correct and reasonable choices, The most economical life and optimum performance of the valve are obtained.
According to the No. 218 document of the Ministry of Housing and Urban-Rural Development in 2004, gray cast iron pipe and fittings shall not be used for municipal water supply, gas and other municipal piping systems. Pipes and fittings with caliber > 400mm are not allowed in sewage treatment plants, drainage pumping stations and municipal drainage pipes. The requirements for use in pressure lines in the net, the valve housing material for urban water supply excludes gray cast iron.
Compared with cast steel, ductile iron has the same strength, but the chemical corrosion resistance is twice that of the former, and it is suitable for use in water supply valves with working temperature between -30*C-350*C and PN≤4.0MPa. Ductile iron is more resistant to corrosion than cast steel. The main reason is that the carbon content of ductile iron is 10 times that of cast steel. The carbon in ductile iron exists in the form of spheroidal graphite. The spherical graphite is much more chemically stable than flake graphite.