the tank connection t and the other working connection b two adjustable throttles a 1 a 4 are arranged in the pump line 10 a further adjustable throttle a 5 is arranged in the tank line 11 these throttles a 1 a 4 and a 5 are also created by the two sliders that is they are adjusted by rotating the two sliders relative to one another the throttles a 1 a 4 and a 5 open as the two sliders are rotated against one another furthermore a short circuiting line 12 with a short circuiting throttle ad is provided this is arranged between the pump line 10 and the tank line 11 the short circuiting line 12 branches off in this case between the two throttles a 1 a 4 the short circuiting throttle ad is open in the neutral position of the two sliders and closes as soon as the two sliders have been rotated against one another through a small angle the opening and closing characteristics of the individual throttles is apparent from fig7 the throttle a 1 can be also be termed a measuring throttle an ls signal is tapped off downstream thereof that is the pressure downstream of the measuring throttle a 1 is determined it is returned to the priority valve 2 and controls that priority valve 2 so that the pressure across the measuring throttle a 1.