A valve is a control component in a pipeline fluid conveying system. It is used to change the cross section of the channel and the flow direction of the medium. It has the functions of diversion, cutoff, adjustment, throttling, check, diversion or overflow and pressure relief.
Valves used for fluid control range from simple shut-off valves to various valves used in extremely complex automatic control systems, with various varieties and specifications. The nominal diameter of the valve ranges from extremely small instrument valves to industrial pipeline valves up to 10 meters in diameter. The valve can be used to control the flow of various fluids, such as water, steam, oil, gas, mud, corrosive media, liquid metals and radioactive fluids. The working pressure of the valve can be between 1.3-10 MPa, and the working temperature can be between -269°C and 1430°C. The valve can be controlled by various transmission methods, such as manual, electric, hydraulic, pneumatic, worm gear, electromagnetic, electromagnetic hydraulic, electro-hydraulic, pneumatic hydraulic, spur gear and bevel gear transmission. Under the action of pressure, temperature or other forms of sensing signals, the valve can act according to predetermined requirements, or simply open or close, without relying on the sensing signal. The valve relies on a drive or an automatic mechanism to move, slide, swing or rotate the opening and closing parts, thereby changing the size of the flow passage area to achieve its control function.
Use of valves :
The valve is a kind of pipeline accessory, which is used to change the channel cross section and the flow direction of the medium, and control the movement of the conveying medium. It has the functions of diversion, interception, regulation, throttling, check, diversion or overflow and pressure relief. Specifically, the valve has the following uses:
1. Cut-off valve: connect or block the medium of each section of the pipeline. Such as gate valve, globe valve, ball valve, plug valve, diaphragm valve, butterfly valve, etc.
2. Regulating valve: Regulate the flow and pressure of the medium in the pipeline. Such as throttle valve, regulating valve, pressure reducing valve, valve, etc.
3. Diversion valve: change the flow direction of the medium in the pipeline, used to distribute, separate or mix the medium. Such as distribution valves, three-way plug valves, three-way or four-way ball valves, traps, etc.