Introduction to Industrial Automation

5.3   Production of Pressurized Air

Pressurized air is produced from compressors, which are electromechanical machines that have 

the ability to pressurize the air into a metallic container (tank) under the desired operational 

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Elements of Electro-Pneumatic Components 

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pressure. In most of the industrial automation cases, it is suggested to have a central station 

for the production of the pressurized air, instead of having independent and distributed local 

compressors. Thus, in this approach, each new pneumatic device is supplied from the existing 

pneumatic network and its installation in the general automation is faster and easier. In general, 

it should be kept in mind that small and mobile compressors are rarely utilized in industrial 

automations.

Pneumatic compressors come in multiple types; however, there are two main categories. 

The first category includes compressors whose operation is based on the principle of move-

ment, where the air is trapped in a chamber, and subsequently the volume of the chamber is 

reduced with the help of a pressing piston. The compressors of this category are called “pis-

ton based compressors”. The second category includes compressors where the pressurization 

is achieved from the acceleration of the air mass and thus are called “turbine compressors”. 

In all cases, the most common operational pressure in the pressurized air circuits is 6–7 bars 

(1 bar = 14.5 psi).