A valve arrangement is provided with a very short minimum valve adjustment time. This is especially suitable for use in respirators or anesthesia apparatuses for metering gases for respirated patients. It has a valve (3, 4) with a seat (3) and with a valve closing part (4) for adjusting the gas flow rate, an inflow line (1) and a discharge line (2) as well as a drive system (5) for controlling the position of the valve closing part (4) relative to the seat (3). A gas flow rate measuring transducer (8) and a control unit (9) are provided for controlling the drive system (5) by means of a control signal. A velocity measuring transducer (7) for measuring the velocity of the valve closing means (4) relative to the seat (3) is present to provide an output signal used to calculate the control signal (40) for the drive system (5).