Control Valve
A control valve modulates flow, pressure or level by moving a plug or disc under a positioner. It is the final control element in a process-control loop.
What is a Control Valve
A pneumatic (or electric) actuator strokes the trim to the positioner setpoint from the control system. Characterised trim (equal-percentage, linear) shapes the flow response for stable control.
Materials & standards
- 316L / 304 or alloy body by duty
- PTFE or metal seat
- Pneumatic diaphragm or piston actuator
- Positioner with 4–20 mA / fieldbus
- Flanged or tri-clamp ends
Typical applications
- Continuous flow and level control
- Chemical and petrochemical plants
- Power and boiler feed
- Mining and slurry
- Hygienic batch control
Control Valve at a glance
| Sealing | Trim-seated, modulating |
|---|---|
| Control | Continuous, positioned |
| Relative cost | Higher (actuator + positioner) |
| Best use | Modulating process control, not simple on/off |
Frequently asked questions
Control valve vs on/off valve?
A control valve modulates to a setpoint for continuous control; on/off valves (ball/butterfly) only open or close.
Pneumatic or electric actuator?
Pneumatic is fast, fail-safe and cheaper for on/off/modulating; electric gives precise modulating control and easy fieldbus but costs more.
What trim characteristic do I need?
Equal-percentage for most processes, linear for level/flow where the relationship is near-linear.
Last updated: 2026-10-08
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