Abstract: A method for checking the controllability of a tank venting valve is described, via which an additional quantity of air charged with fuel vapors can be supplied to the intake area of an internal combustion engine.In order to carry out this method, quantities in the area of the tank venting valve are measured which change when a throughput quantity passes through the tank venting valve. In this connection, differences of these quantities before and after activation of the tank venting valve are preferably evaluated. If necessary, for example if required by the sensitivity of the sensors used, an execution of the checking can be made dependent on the pressure in the intake area.

Abstract: A diaphragm valve which may serve as an equal pressure valve or as a pressure equalizing valve of a fuel metering and distributing unit for an externally ignited internal combustion engine. The valve has a flexible diaphragm having a clamped diameter and to which a valve plate is connected. The valve plate operatively cooperates with a valve seat of the valve and has a diameter which is as large as possible in relation to the clamped diameter of the diaphragm. The valve also includes a stationary thrust plate which is concentrically disposed relative to the valve seat, which defines a knife-shaped edge which lies in a common plane with the valve seat and which operatively cooperates with the valve plate. The knife-shaped edge has a diameter which is as large as possible in relation to the diameter of the valve plate.