Control valve

A control valve is a valve used to control fluid flow by varying the size of the flow passage as directed by a signal from a controller.^[1] This enables the direct control of flow rate and the consequential control of process quantities such as pressure, temperature, and liquid level.

In automatic control terminology, a control valve is termed a "final control element".

^ Instrument Society of America Standard S561.1, 1976. as reproduced in the "Fisher control valve handbook" fourth edition 1977. Current: Fourth Edition

[1] Instrument Society of America Standard S561.1, 1976. as reproduced in the "Fisher control valve handbook" fourth edition 1977. Current: Fourth Edition

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