The regulating valve is usually composed of two parts, the actuator and the valve component. In some occasions it can be equipped with valve positioner, hand wheel mechanism and other accessories.
In the field of industrial automation process control, by receiving the control signal output from the control unit, the regulating valve is the final control element of the process parameters such as the medium flow, pressure, temperature and liquid level changed by power operation.
The regulating valves are generally divided into single-seat control valve, two-seat control valve, sleeve control valve, angle control valve, three-way valve, diaphragm valve, butterfly valve, ball valve, eccentric rotary valve. The first six kinds are straight stroke, and the latter three kinds are angular travel.Straight travel is mainly divided into through single seat type and through engine type , and the though engine type has the characteristics of large flow capacity, unbalanced and stable operating, so it is usually suitable for high flow, low pressure drop and leakage occasions.