Flow valve or shut-off cock for flow networks with sealing means

摘要

A flow valve or shut-off cock for flow networks having sealing means of particular features which make its design easy and increase its tightness and useful life. This valve provides sealing means reacting in proportion to the flow pressure, for which purpose sealing means of the lung type are available, that is to say, the sealing means consist in a flexible and hollow body, which is inflated by the flow pressure going into the valve, pressing one of the walls of the flexible element against the opening of the valve intended to be blocked or obstructed. This sealing element of the lung type is controlled by the rotation of a rigid stem component partially surrounding it in its upper zone and in external side areas.