A valve for opening or closing a flow section has: a valve disk, a valve plunger and a transmission for converting rotary motion into translational motion. The transmission has a rocker arm mounted to rotate about an axis of relation, the rocker arm is linked to the valve plunger by connecting rods, and the connecting rods are mounted to rotate relative to the rocker arm and the valve plunger. A restoring device generates a force component to counteract a movement of the valve plunger transmitted to the valve plunger by the rocker arm and the connecting rods.