A valve for closing a fluid line, comprising: an inlet element with an inlet line; an outlet element with an outlet line; a closing element which, in a first state, allows a fluid passage between the inlet line and the outlet line and which, in a second state, closes the fluid passage, wherein the closing element, in the first state, is fixedly connected to the inlet element or the outlet element and, in the second state, is detached from the inlet element or the outlet element; an actuator which, when actuated, is configured to move the closing element from the first state towards the second state; and a pretension element which is pretensioned and is configured to move the closing element into the second state after actuation of the actuator.