A valve includes a flow chamber, an actuating chamber, and an opening. An actuating element can close or open the valve opening. An SMA element can move the actuating element in the opening direction. The flow chamber and the actuating chamber are separated by a separating wall. A first area of the flow chamber is attachable to an air supply unit to supply air to the flow chamber. A second area of the flow chamber is attachable to a media reservoir and is connectable to atmosphere to release air from the flow chamber via an opening. An actuator is pivotable on the valve housing via a second end section, and has a first end section coupled adjacent a first end of the actuating element so that the opening to the atmosphere is either released or closed.