The disclosed valve device includes first, second and third user ports. A pressure accumulator connects with the first user port. With the accumulator fully charged, a pressure port connected to a pump communicates with the second user port. With the accumulator evacuated, the pressure port communicates with the first user port. In the event of a fluid demand at the third user port, the pressure port will be connected to the third user via a control valve. The control valve is a non-return valve in a channel connecting the first user port to the third user port, which opens under influence of a pressure in the first user port.