A device for mutually independent control of regulating devices (1-6) for controlling fluid flow between a hydrocarbon reservoir (50) and a well (51) comprises a flow controller (54) and a hydraulic actuator (56). The actuator (56) is flow-relatedly arranged in series with at least two associated control valves (20-25) in a path (18, 19) between two hydraulic pipes (11, 14). The control valves (20, 25) are controlled to open for the flow of hydraulic liquid to the actuator (56) by the pressure in the two hydraulic pipes (11, 14), and the combination of two hydraulic pipes (11, 14) which are connected to an actuator (56) is different for independently controllable regulating devices (1-6).