A metering valve assembly comprising a ferrule and a valve housing defining an internal cavity. The valve housing accommodates an annular flange and a compression spring therein with a valve gasket closing the internal cavity. The valve housing is attached to the ferrule such that a stem portion of the valve stem protrudes through apertures provided in both the valve gasket and the ferrule. A stem portion has a discharge passageway which is normally closed by the valve gasket. Either an undersurface of the annular flange or a mating surface of the valve housing is provided with a compressible sealing member while the other is provided with an annular edge. The compressible sealing member and the annular edge form a seal therebetween, when the valve stem is sufficiently depressed, to partition the interior cavity into a metering chamber and a separate filling chamber whereby product may only be dispensed solely from the metering chamber when a product flow path is established.