Self-closing valve device, preferably self-closing sanitary mixing and shut-off valve device, comprising - a valve closing body unit which is disposed to be movable between a valve closed position and a valve open position, - a valve actuation unit which is disposed to be movable between a closed position, in which it retains the valve closing body unit in the valve closed position thereof, and an open position, in which it retains the valve closing body unit in the valve open position, wherein the valve actuation unit moves from its closed position to its open position upon user-operation and moves, in a normal operation mode of the self-closing valve device, from its open position to its closed position in a self-acting manner, and - a blocking unit which is user-operated displaceable between an enable position, in which it enables the self-acting movement of the valve actuation unit from the open position thereof to the closed position thereof, and a blocking position, in which it blocks the self-acting movement of the valve actuation unit from the open position thereof to the closed position thereof in a retaining position, in which the valve actuation unit, in a special operation mode of the self-closing valve device, retains the valve closing body unit in a special operation valve open position, - wherein the valve actuation unit comprises a moving actuation part which, during the self-acting movement of the valve actuation unit from its open position to its closed position, moves relative to a non-moving valve device part, and the blocking unit comprises a user-operated blocking element which, in the blocking position of the blocking unit, acts as a mechanical movement blocker between the moving actuation part and the non-moving valve device part, characterized in that - it comprises a valve housing body which has a tool insertion opening, and the blocking element includes a blocking pin which is retained on the non-moving valve device part to be displaceable between a blocking pin unblocked position and a blocking pin blocked position and has a tool interface facing the tool insertion opening, or - it comprises a valve housing body and the blocking element includes a magnet body disposed in the valve housing body, which magnet body is displaceable between a magnet body enable position and a magnet body blocked position for blocking cooperation of the non-moving valve device part with the moving actuation part by means of an actuation magnet which is capable of being positioned outside the valve housing body. - a valve closing body unit which is disposed to be movable between a valve closed position and a valve open position, - a valve actuation unit which is disposed to be movable between a closed position, in which it retains the valve closing body unit in the valve closed position thereof, and an open position, in which it retains the valve closing body unit in the valve open position, wherein the valve actuation unit moves from its closed position to its open position upon user-operation and moves, in a normal operation mode of the self-closing valve device, from its open position to its closed position in a self-acting manner, and - a blocking unit which is user-operated displaceable between an enable position, in which it enables the self-acting movement of the valve actuation unit from the open position thereof to the closed position thereof, and a blocking position, in which it blocks the self-acting movement of the valve actuation unit from the open position thereof to the closed position thereof in a retaining position, in which the valve actuation unit, in a special operation mode of the self-closing valve device, retains the valve closing body unit in a special operation valve open position, - wherein the valve actuation unit comprises a moving actuation part which, during the self-acting movement of the valve actuation unit from its open position to its closed position, moves relative to a non-moving valve device part, and the blocking unit comprises a user-operated blocking element which, in the blocking position of the blocking unit, acts as a mechanical movement blocker between the moving actuation part and the non-moving valve device part, characterized in that - it comprises a valve housing body which has a tool insertion opening, and the blocking element includes a blocking pin which is retained on the non-moving valve device part to be displaceable between a blocking pin unblocked position and a blocking pin blocked position and has a tool interface facing the tool insertion opening, or - it comprises a valve housing body and the blocking element includes a magnet body disposed in the valve housing body, which magnet body is displaceable between a magnet body enable position and a magnet body blocked position for blocking cooperation of the non-moving valve device part with the moving actuation part by means of an actuation magnet which is capable of being positioned outside the valve housing body.