Compressed Air: Units

Estimated Reading Time: 2 minutes

December 11, 2020

Learn About the Units of Compressed Air

In this compressed air guide, we have previously discussed air, atmospheric pressure and compressed air. We now would like to discuss the units in compressed air.

This could be an advantage to your production, as you learn more and more about all the details surrounding compressed air. Continue reading through our compressed air guide to learn even more!

Atmospheric pressure

In the international unit system, Pa (Pascal) is the accepted basic unit of pressure. As 1 pascal in compressed air is a very small amount of pressure we typically use the unit:
kPa (1 kilopascal = 1000 Pa)
or
MPa (1 megapascal = 1000 kPa)

The general air pressure on the earth's surface can be specified in different ways, with more or less the same meaning:
1 atm (atmostar) = 1 kp/cm² (kilopond/cm²)
1oo kPa (kilopascal) = 1 bar

Compressed air

Compressed air pressure is typically specified as overpressure; i.e. pressure above normal atmospheric pressure. This is usually implicit but is sometimes clarified with an (e), kPa(e).

A compressor's capacity; i.e. the amount of compressed air that can be supplied per unit of time; specified in:

l/min (liters/min), l/sec (liters/second) or m³/min (cubic meters/minute).

Capacity refers to atmospheric pressure expanded air.

An (N) before the device; e.g. (N) l/sec stands for "normal" and means that the volume specification applies to a specific ambient pressure and a specific temperature. In most practical cases, (N) l/sec is equivalent to l/sec.