Patent ID: 7967023

Claim:
A control valve for use in liquid-carrying systems, comprising: a valve housing ( 3 ) with an inlet side and an outlet side, and including an arrangement for maintaining a constant differential pressure between the inlet side and the outlet side independently of the liquid amount flowing therethrough, wherein a throttle element sets itself in a balance under the influence of the inlet pressure on the one side and the outlet pressure and a spring pressure on the other side, and further comprising: an arrangement for adjusting an amount of liquid flowing therethrough, the arrangement including two cooperating valve members ( 4 , 6 ) arranged in the flow path, said valve members being constructed as two concentric rings which each have a recess extending in the circumferential direction, an outer concentric ring ( 4 ) being fixed relative to the valve housing ( 3 ), an inner concentric ring ( 6 ) being displaceable in a circumferential direction under the influence of a rotatable handle ( 10 ), such that a greater or smaller overlap of the outer stationary recess and the inner displaceable recess may be established manually in the circumferential direction, the inner ring with the displaceable inner recess being displaceable also in the axial direction, so that a greater or smaller overlap of the outer stationary recess and the inner displaceable recess may be provided in the axial direction, the inner ring being connectable to an actuator for adjusting the axial overlap.