to the control pressure branch line 23 and 24 communicates the maximum and minimum protection pressures of the pressure limiting valves 18 and 19 are therefore adjustable separately from one another where the minimum protection pressure is dependent upon the setting of the spring and the maximum protection pressure is dependent upon the sum of the spring force and the force generated by the control pressure this has the advantage that the braking moment of the consumer 6 can also be regulated in dependence upon a theoretical value to be predetermined the outlay required for this purpose is low as the pressure limiting valve 18 and 19 provided in any event for the protection of the consumer 6 additionally assumes this function thus both the driving and the braking moment are set by control pressure from the same control pressure source namely the control pressure source provided for the driving of the directional control valve connected into the ls line 12 is a priority valve 32 which in a first operating position connects a line section 12b which branches off from the consumer 8 downstream of the directional control valve 7 via a non return valve to the required flow regulator 2 and in a second operating position connects this line.