The invention concerns a fail-safe valve having a valve element, and a control motor being connected with the valve element via a driveline. It is endeavored to ensure the tightness of the refrigeration system in a simple manner. For this purpose, it is ensured that the valve element is located inside and the control motor outside a closed valve housing, that the drive line has a magnetic coupling, which acts through the housing, and that the valve element is pressure-released. In addition, a resetting device is provided that causes the valve element to be returned to a predetermined position upon the undesired cessation of control motor operation.