Ductile iron pipe is lighter, stronger and more durable than cast iron. The difference between cast iron and ductile iron is the graphite form. In ductile iron, the graphite form is spherical or spheroidal. In cast iron, it is in the form of flakes. 

Ductile iron pipe in the medium and small caliber to give the connection between the pipe and the pipe, using socket or flange type interface method; ductile iron, allowable limit of the corner must have superior seismic resistance and sealing. The main components of ductile iron pipe are carbon, silicon, manganese, sulphur, phosphorus and magnesium.

Gate valve leakage is generally divided into internal leakage and external leakage, resulting in gate valve leakage for a number of reasons, requiring in-depth analysis and research in order to take appropriate disposal measures.

China's ductile iron pipe industry started in the early 1990s and has developed rapidly under the strong support of the China Urban Water Supply Association. After nearly 20 years of practical use, its safety and practicality have been generally recognized by the water supply industry.

Butterfly valve has simple structure, small volume, light weight, material consumption, small installation size, and small driving torque, easy and rapid operation, and also has good flow withering function and closing sealing characteristics, is one of the fastest growing varieties of valves in recent years.