1-2. Control Valve Structure
This device is composed of a valve body and an actuator. The valve body consists of a valve,
bonnet, valve plug, and other components. The actuator consists of a diaphragm, spring, and
other components. Figure 1-2 illustrates the structure of this device.
Actuator
coil spring
Diaphragm
Valve plug
Valve
Bonnet
Figure 1-2. Structure
Names and functions of the components are described below.
Name Function
Valve body
•
Controls fluid flow.
•
Connects to a pipe and contains all valve components.
Valve plug
•
Regulates flow rate, pressure, etc., by changing the size of the flow area.
Valve
•
The part through which the fluid flows. Connects to a pipe.
•
The main component of the pressure vessel
Bonnet
•
Regulates the valve plug performance in accordance with a change in flow.
•
A component of the pressure vessel
Actuator
•
Adjusts valve travel in accordance with the signal received.
Diaphragm
•
Converts air pressure.
Spring
•
Adjusts valve plug position.
For details on the structure of the valve body, Figure 5-2 to Figure 5-4.
For details on the structure of the actuator, Figure 6-1 to Figure 6-4.
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