The oxygen and nitrogen generators are constructed according to the principle of operation P.S.A. (Pressure Swing Adsorption) and are composed by  a minimum of two absorbers filled up with molecular sieve.

The absorbers are crossed alternatively by the compressed air (previously purified in order to  eliminate oil, humidity and powders) and produce nitrogen or oxygen.

While a container, crossed by the compressed air, produces gas, the other regenerates itself losing to pressure atmosphere the gases previously  adsorbed.
The process comes repeated in cyclical way.