The control valve, also known as the control valve, is a device that uses power operation to change and regulate the process parameters of pipeline medium flow, pressure, temperature, liquid level and other process parameters in the field of industrial automation process control.
Generally speaking, the valve body of the conditioning valve is universal, which can be matched with the electric actuation mechanism or other fulfillment mechanisms, and can be divided into three varieties according to the control of the fulfillment equipment: electric conditioning valve, pneumatic conditioning valve, and self-operated conditioning valve
1. Electric conditioning valve
Electric conditioning valve is a very widely used control valve, mainly composed of electric actuation mechanism and conditioning valve, with electricity as the power, by receiving the signal of the controller, drive to change the size of the valve switch, adjust the area of the fluid path, so as to change the flow, pressure, temperature and other working parameters of the fluid.
2. Pneumatic conditioning valve
Pneumatic conditioning valve is a valve that uses compressed air as the power and the area of the fluid path is conditioned by the signal of the controller to change the fluid flow
3. Self-operated conditioning valve
The self-operated conditioning valve, also known as the direct effect conditioning valve, does not require any external power, and directly uses the energy of the medium to be adjusted to operate the conditioning mechanism, complete automatic control, and complete the conditioning of temperature, pressure, flow and other parameters.
The most commonly used classification methods in China are as follows:
It is classified according to the method of conditioning, flow characteristics, use and effect, spool shape, special use (i.e., special, special valve), upper bonnet method, etc., and other thermometer pressure classifications have been omitted
1. According to the conditioning method, it can be divided into: conditioning type, cutting type, conditioning cutting type:
2. According to the flow characteristics, it can be divided into: linear, logarithmic (percentage), parabolic, fast open,
3. Classification according to usefulness and effect:
1. Two valves: Mainly used to close or connect the medium:
2. Conditioning valve: It is mainly used in the conditioning system, and when selecting the valve, the flow characteristics of the conditioning valve need to be confirmed
3. Diverter valve: used for dispensing or mixing media
4. Shut-off valve: Usually refers to a valve with a leakage rate of less than 1/100,000
Fourth, according to the upper bonnet method: (a) ordinary type; (b) (Heat absorption) type; (c) long-necked; (d) Bellows sealed type
5. Classification according to the shape of the spool: (a) Flat spool; (b) Plunger-shaped spool; (c) window-shaped spool; (d) Sleeve-shaped spool; (e) Multi-stage spool; (f) Offset spool; (g) Butterfly spool; (h) Ball spool
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