Let us give the valve a definition

The valve is in a fluid system, to be used to control the direction of the fluid, pressure, flow apparatus. The valve is to make the pipe and the equipment within the medium (liquid, gas, powder) flow or stop, and can control the flow apparatus.Range Valve

The valve is a control means in the pipeline fluid delivery system, which is used to change the passage cross-section and the direction of medium flow, having a deflector, cutoff, throttled non-return, shunt, or overflow relief function. For fluid control valves, shut-off valve from the most simple to the highly complex automatic control system used in a variety of valves, many varieties and specifications, the valve nominal diameter to pass from tiny instrument valve diameter of 10m, industrial piping with valves. Work pressure valve can be used to control various types of fluid flowing water, steam, oil, gas, mud, and a variety of corrosive media, liquid metal and radioactive fluids, valves 0.0013MPa to 1000MPa ultra high pressure, working temperature -300 ℃ from the ultra-low temperature to a high temperature of 1430 ℃. Control of the valve can be used a variety of transmission, such as manual, electric, hydraulic, pneumatic, turbine, electromagnetic, dynamic, electromagnetic hydraulic, electric hydraulic, pneumatic and hydraulic, spur gear, bevel gear drive, etc.; pressure, temperature or other forms of sensor signals, according to the predetermined requirements of operation, or does not rely on the sensor signal and simple open or closed, valves rely on the driver or automatic mechanism of the opening and closing member for lifting, sliding, swing or rotary movement, thus changing the size of the area of the flow channel to achieve its control function.hot Water Heater Gas Control Valve