What is a manual valve?

Manual valves use handwheels, handles, levers, and sprockets to manipulate the valve action by manpower. When the valve opening and closing torque is large, this wheel or worm gear reducer can be set between the handwheel and the valve stem. If necessary, the universal joint and drive shaft can also be used for remote operation.
The manual valve is a control part in the pipeline fluid conveying system. It is used to change the passage section and the flow direction of the medium. It has the functions of diversion, cut-off, adjustment, throttling, check, shunt or overflow and pressure relief. Valves used for fluid control, the nominal diameter of the valve ranges from extremely small instrument valves to industrial pipeline valves with a diameter of up to 10m. The valve can act according to predetermined requirements under the action of pressure, temperature or other forms of sensing signals, or simply open or close without relying on the sensing signal. The valve relies on the drive or automatic mechanism to make the opening and closing parts lift and slide. , pendulum or rotary motion, thereby changing the size of its flow channel area to achieve its control function.
The valve control can adopt various transmission methods, such as manual, electric, hydraulic, pneumatic, worm gear, electromagnetic, electromagnetic-hydraulic, electric-hydraulic, pneumatic-hydraulic, spur gear, bevel gear drive, etc. , 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, the working pressure of the valve can be from 0.0013MPa to 1000MPa ultra-high pressure, From the ultra-low temperature of -269℃ to the high temperature of 1430℃.