CHECK VALVE OPERATED BY A FIRST-CLASS LEVER CONNECTED TO A PAIR OF FLOATERS, ONE OF WHICH BEING BALLASTED

摘要

The invention relates to a direct-operated check valve which can be connected to a delivery duct to adjust the introduction of a liquid, under pressure in said duct, into a tank. The valve comprises an inlet opening, an outlet opening and a plug housed inside a chamber interposed between said openings. The plug is movable between an opening position, at which it allows a liquid to flow from the inlet opening to the outlet opening, and a closing position, at which the plug sealingly obstructs the outlet opening. The valve is connectable to the duct so that an overpressure at the inlet opening with respect to the outlet opening moves the plug from the opening position to the closing one. The plug is operated by a first-class lever connected to two floaters, one of which ballasted. More precisely, a first floater is integrally connected to the lever at a first arm thereof. The second floater, ballasted, is connected to said first arm by means of a cord. The lever is in contact with the plug at a second arm thereof opposite to said first arm. An Archimedes' thrust acting on the first floater allows the movement of the plug from the opening position to the closing one, closing the valve. The weight force acting on the second floater, when not immersed in said liquid, determines the movement of the plug from the closing position to the opening one, opening the valve.