A control valve is a power operated device which changes the fluid flow rate in a process control system. It consists of a valve (i.e. an assembly forming a pressure retaining envelope containing internal means) connected to an actuator that is capable of changing the position of a closure member in the valve in response to a signal from the controlling system.
Main control valve types are as follows:
- Globe, single port
- 3 V-port plug
- 4 V-port plug
- 6 V-port plug
- Contoured plug (linear and equal percentage)
- 60 equal diameter hole drilled cage
- 120 equal diameter hole drilled cage
- Characterized cage, 4-port
- Globe, double port
- Ported plug
- Contoured plug
- Globe, angle
- Contoured plug (linear and equal percentage)
- Characterized cage, 4-port
- Venturi
- Globe, small flow trim
- V-notch
- Flat seat (short travel)
- Rotary
- Eccentric spherical plug
- Eccentric conical plug
- Butterfly (centered shaft)
- Swing-through (70°)
- Swing-through (60°)
- Fluted vane (70°)
- Butterfly (eccentric shaft)
- Offset seat (70°)
- Ball
- Full bore (70°)
- Segmented ball