What are the basic knowledge of valves?

Valves are control components in fluid conveying systems, with cutoff, regulation, diversion, prevention of countercurrent, voltage stabilization, shunt or overflow pressure relief and other functions. Valves for fluid control systems, ranging from the simplest globe valves to the various valves used in extremely complex automatic control systems, are varied in variety and specifications. Valves can be used to control the flow of various types of fluids, such as air, water, steam, various corrosive media, mud, oil, liquid metals and radioactive media.

A valve is a device used in a fluid system to control the direction, pressure, and flow of a fluid. Valves are devices that allow the media (liquids, gases, powders) in the piping and equipment to flow or stop and control their flow. Valve is the control part in the pipeline fluid conveying system, it is used to change the path section and the flow direction of the medium, with diversion, cutoff, throttling, check back, shunt or overflow discharge and other functions. Valves for fluid control, from the simplest globe valves to a wide range of valves used in extremely complex automatic control systems, have a wide variety and specifications, and the nominal diameter of valves range from tiny instrument valves to industrial piping valves with diameters up to 10m. Valves can be used to control the flow of various types of fluids, such as water, steam, oil, gas, mud, various corrosive media, liquid metals and radioactive fluids, and the valve's operating pressure can range from 0.0013MPa to 1000MPa of ultra-high pressure, operating temperature from 269 ℃ ultra-low temperature to 1430 ℃. Valve control can be used in a variety of transmission methods, such as manual, Electric, hydraulic, pneumatic, turbo, electromagnetic, electromagnetic fluid, electro-hydraulic, gas-liquid, positive gear, bevel gear drive, etc., can be under pressure, temperature or other forms of sensing signal, according to the action of the predetermined requirements, or do not rely , The valve relies on the drive or automatic mechanism to make the opening and closing parts for lifting, sliding, spinning or rotary movement, thus changing the size of its runner area to achieve its control function.