Force per unit area, usually expressed in pounds per square inch (PSI) or BAR.

The total pressure measured from absolute zero ( i.e., from an absolute vacuum).

The pressure encountered on the return side of a system.

The pressure at which a pressure operated valve begins to pass a gas.

Is the saturation pressure at the critical temperature.

Is the temperature at which moisture begins to condense in a compressed air system.

Is the total gas pressure (static plus velocity) at the discharge port of the compressor. Velocity pressure is considered only with dynamic compressors.

Resistance to flow. Defined as the difference in pressure upstream and downstream.

A device that indicates pressure differential above or below atmospheric pressure.

Is the total pressure (static plus velocity) at the inlet flange of the compressor.

In spray painting applications, a sealed paint cup with a paint gun which puts a measured amount of air pressure into it. This then forces the paint to the gun for atomization.

Difference between minimum and maximum pressures for an air compressor. Also called cut in-cut out or load-no load pressure range.

The qualified operating pressure which is recommended for a component or a system by the manufacturer.

A valve which enables pressure to be reduced, or kept constant at a desired level.

A device actuated by inlet static pressure and designed to open during an emergency or abnormal condition to prevent a rise of internal pressure in excess of a specified value.

The difference between the discharge pressure and the intake pressure.

The pressure measured in a flowing stream (liquid or gas) in such a manner that no effect on the measurement is produced by the velocity of the stream.

The pressure which overcomes the total resistances in a system. It includes all losses as well as useful work.

The pressure that would be produced by stopping a moving stream of liquid or gas.

The total pressure minus the static pressure in an air or gas stream.