A control valve modulates flow in response to a signal, using a plug or rotary element positioned by an actuator. The valve body, actuator, positioner, airset and accessories form a system: the calibration, the linkage and the tubing are part of what makes it useful.
Every regulated process loop has one. Control valves are replaced during turnarounds, unit revamps and digital upgrades, and the removed assemblies often sit in a warehouse because nobody wants to scrap a valve with a working positioner on it.
We buy control valves in any quantity — single items, mixed pallets or whole cribs, including valves that need repair and assemblies that are missing parts. We do not require a clean inventory before reviewing a list.
| Common patterns | Globe, cage-guided and top-guided, Rotary plug, eccentric plug and ball control, Spring diaphragm pneumatic actuator, Piston and rotary vane actuator |
|---|---|
| Typical service | Refinery process control, Chemical and petrochemical, Power generation |
| What we look at | Tag number, body size and class, trim characteristic, actuator type and size, positioner model, and whether the assembly is complete. A photograph of the tag plate and one of the whole assembly answers most of it before anyone opens a toolbox. |
| What to keep | Keep the complete assembly: body, actuator, positioner, airset, handwheel, tubing and the tag plate. Do not cut the stem to separate the actuator, and do not remove the positioner to sell separately unless you have checked whether the assembly is worth more intact. |
Patterns and variants
What turns up most often
Variants matter because they change the buyer pool. A standard pattern sells to a rebuilder or a plant with the same service; a specialised trim sells to a much smaller group but often at a higher price. If you are unsure which variant you have, the nameplate or the trim marking will usually say.
Before it leaves site
How to protect the value
Keep the complete assembly: body, actuator, positioner, airset, handwheel, tubing and the tag plate. Do not cut the stem to separate the actuator, and do not remove the positioner to sell separately unless you have checked whether the assembly is worth more intact.
Where they come from
Industries and services
- Refinery process control
- Chemical and petrochemical
- Power generation
Most of the surplus we see comes from plants that have replaced equipment for a reason that has nothing to do with the valve: a unit was re-rated, a line was re-piped, a control loop was upgraded or a project was re-scoped. The valve is simply the part that has to move.
Related patterns
Other valve types
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Read →Questions sellers ask
Do you buy control valves without the positioner?
Yes, but the value changes. A complete assembly with a known positioner is a different proposition from a bare body with an actuator, so be specific about what is attached.
Should I remove the actuator before selling?
No. Keep it together. Complete assemblies are worth more than the sum of their parts, and separating them risks damaging the stem and the linkage.
What documentation helps most?
The tag number, the valve data sheet if it still exists, and the calibration record. If those are gone, a clear photograph of the body and actuator nameplates is enough to start.