Pressure

Thermodynamically, the normal force exerted by a homogeneous liquid or gas, per unit of area, on the wall of the container.

Pressure Control

A device which responds directly or indirectly to deviation from a desired pressure by actuating a control or initiating a control sequence.

Pressure Dependent

The flow rate through a flow control device varies in response to changes in system pressure.

Pressure Independent (PI)

The flow rate through a flow control device is not affected by changes in system pressure.