The compressed air valve is the result of a research project focused on the reduction of weight, noise, assembly time and manufacturing costs of products that make compressed air suitable for respiration. The intentions were widely exceeded through the creation of just three injection moulding parts. The airflow is controlled by a simple and effective invention, based on a control knob revolving around its own axle. This principle is patented. Sound is reduced by a replaceable felt cartridge. The diabolical shape of the knob prevents accidental distortion of a preset airflow.