Abstract: A device for adjusting the flow rate of a screw- type compressor supplying compressed gas, having a control valve to supply a control pressure (Pn) which is in proportion to the gas pressure (Pw) as of a gas pressure (A); an electronic speed controller which sets a lower rotational speed (N) as the control pressure (Pr1) rises; an inlet valve controlled by the control pressure (Pr1) with a valve element which can freely move inside a housing and where a non-return valve is actuated by a spring provided in a line between the inlet valve and the control valve.

Abstract: Improved device (7) for adjusting the flow rate of a screw-type compressor (1) supplying compressed gas, consisting of a control valve (14) which supplies a control pressure (Pn) which is in proportion to the gas pressure (Pw) as of a gas pressure (A); an electronic speed controller (20) which sets a lower rotational speed (N) as the control pressure (Pr1) rises; an inlet valve (8) controlled by the control pressure (Pr1) with a valve element (10) which can freely move inside a housing (9) and whereby a non-return valve (22) actuated by means of a spring (23) is provided in a line (21) between the inlet valve (8) and the control valve (14).