Manual valves use handwheels, handles, levers, and sprockets to control valve movements manually. When the valve opening and closing torque is large, this wheel or worm gear reducer can be installed between the handwheel and the valve stem. When necessary, universal joints and drive shafts can also be used for remote operations. The valve relies on a drive or automatic mechanism to make the opening and closing parts lift, slide, swing or rotate, thereby changing the size of its flow channel area to achieve its control function. The manual valve is a control component in the pipeline fluid transportation system. It is used to change the passage section and the flow direction of the medium. It has the functions of diversion, cutoff, regulation, throttling, check, diverting or overflow pressure relief. Valves used for fluid control, the nominal diameter of the valve ranges from extremely small instrument valves to industrial pipeline valves with diameters up to 10m. The valve can act according to predetermined requirements under the action of pressure, temperature or other forms of sensing signals, or can be simply opened or closed without relying on sensing signals. The valve relies on the drive or automatic mechanism to lift and slide the opening and closing parts. , pendulum or rotary motion, thereby changing the size of its flow channel area to achieve its control function.