The
valve is the control part in the fluid conveying system of the pipeline, and it is used for changing flow directions of channel sections and media. A
valve has diverting, cutting off, throttling and other functions. From the simplest globe valve to the extremely complex various valves used in the automatic control system, valves used for fluid control have many kinds and specifications. The
valve ranges from very tiny instrument valves to valves with a diameter of 10m which are used for industrial pipelines. A valve is used for controlling flows of various fluids such as water, steam, oil, gas, mud, all kinds of corrosive media, liquid metal and radioactive fluids. The working pressure of the valve can be from 0.0013MPa to 1000MPa, and the working temperature of the valve can be at an ultralow temperature of -270 ℃ to a high temperature of 1430 ℃.
The control of the valve can adopt various driving methods such as manual, electric, hydraulic, pneumatic, turbine, electromagnetic, electro-hydraulic, pneumatic-hydraulic, spur gear and bevel gear driving methods. In this article, we are going to introduce how to select the
valve according to industry characteristics.
1.
Valves for urban gas: Urban gas accounts for 22% of the entire natural gas market, and the demand for
valves is great. Valves also have many types. Valves which are mainly used for urban gas are ball valves, plug valves, pressure reducing valves and safety valves.
2.
Valves for city heat supply: A large number of metal sealed
butterfly valves, horizontal balance valves and directly-buried ball valves are applied to city heat supply, because this kind of valve can solve the problems of vertical pipelines and horizontal hydraulic disorder so as to serve a purpose of energy saving and heat balance.
3.
Valves for urban construction: A low-pressure valve is usually adopted for urban construction.
Valves for urban construction are in the development direction of being energy saving and environmentally friendly now. Low pressure iron gate valves are replaced with environmentally friendly rubber plate valves, balance valves, center line butterfly valves and metal sealed butterfly valves gradually. Balance valves, soft sealed
gate valves and butterfly valves are mainly used for Chinese urban construction.
4.
Valves for environmental protection: Center line butterfly valves, soft sealed gate valves, ball valves and exhaust valves (used to discharge the air in the pipeline) are mainly applied to the water supply system in the domestic environmental protection system. Soft sealed gate valves and butterfly valves are mainly used for the sewage treatment system.
5.
Valves for long-distance pipelines: Long-distance pipelines are mainly crude oil and crude oil product pipelines. Forged three-way full bore ball valves, anti-sulfur flat gate valves, safety valves and
check valves are widely used for this kind of pipeline.
