A tank valve with a valve seat and a valve disc can be displaced relative to the valve seat along a displacement direction into either a closed position or a through-flow position. The valve seat includes a plate shaped part and a ring-shaped part. The valve disc has a first contact area which contacts the first plate shaped part of the valve seat when the tank valve is in the closed position. The valve disc also has a second contact area which is in contact with a second part of the valve seat when it is in the closed position.