A control valve is a device that controls the flow of liquid or gas. Kimray control valves are linear valves that have a stem in the middle. These can operate in modulating control or on/off applications.
How Control Valves Work
To “control” the liquid or gas, a control valve can open or close fully (on/off), or slightly (modulating). Modulating valves can open or close slightly. They do this in order to change the size of the opening through which the media is flowing. They may also be moved to fully closed or fully open.
However, a valve by itself will not do anything. In order to open or close, the valve actuator must receive a signal from an outside source. This is provided by one of the following:
- Pneumatically actuated control valve: a pneumatic pilot or liquid level controller
- Electrically actuated control valve: an electric pilot, liquid level controller, Programmable Logic Controller (PLC), or Remote Terminal Unit (RTU)
In the case of a pneumatically actuated High Pressure Control Valve installed on a separator to hold back pressure, this signal is provided by a pneumatic pressure pilot. The pilot on this package senses upstream pressure and sends a corresponding signal (typically processed supply gas) through tubing into the actuator of the valve. The actuator reacts to this pilot signal by either closing or opening the valve.
In the case of an electrically actuated High Pressure Control Valve installed on a separator to hold back pressure, the signal is provided by an electric pilot (or PLC). The electric pilot receives an analog 4-20mA signal from a sensor, which represents a process condition. The pilot then conditions this signal and sends a corresponding signal (4-20mA loop) to the electric actuator of the valve. The actuator reacts by either opening or closing the valve.
Other Control Valves
If you have further questions or would like help setting up your control valve, reach out to your local Kimray store or authorized distributor.