CFM
Cubic feet per minute, a commonly used airflow unit.
SCFM
Standard cubic feet per minute, airflow referenced to defined standard conditions.
PSI
Pounds per square inch, a pressure unit.
Load factor
The relationship between average compressor demand or power and a stated full-load condition.
Rotary screw compressor
A compressor that uses meshing rotary elements to compress air.
Reciprocating compressor
A compressor that uses pistons moving in cylinders.
Centrifugal compressor
A dynamic compressor that increases air velocity and converts it to pressure.
Air receiver
A pressure vessel used to store compressed air and help manage demand or moisture.
Pressure dew point
The temperature at which water vapour condenses at the stated compressed-air pressure.
Pressure drop
A reduction in pressure caused by flow through piping, filters, dryers, valves or other restrictions.
Purge air
Compressed air consumed by some dryer designs during regeneration or operation.
Specific power
Compressor input power relative to delivered airflow under stated conditions.
Leak survey
A structured process to locate, tag, quantify and prioritize compressed-air leaks.
Authority having jurisdiction
The regulator, inspector or other authority responsible for applicable requirements.