A reservoir assembly comprising a reservoir housing, a piston, and a locking plug, both movably arranged inside the reservoir housing wherein the volume between the piston and the locking plug defines a reservoir cavity. The reservoir assembly further comprising a reservoir outlet and an actuator configured to act on the piston wherein the locking plug is configured to be movable from a first position to a second position wherein in the first position the reservoir outlet is not in fluid communication with the reservoir cavity. The reservoir assembly further comprising an interlock configured to prevent movement of at least one of the locking plug and the piston wherein the interlock having a locked position and an unlocked position.
