COMBINATION VACUUM RELIEF VALVE AND PRESSURE RELIEF VALVE WHICH ARE PROTECTED FROM THE ATMOSPHERE

摘要

Case 640COMBINATION VACUUM RELIEF VALVE AND PRESSURE, RELIF VALVEWHICH ARE PROTECTED FROM THE ATMOSPHEREAbstract of the DisclosureA vacuum relief valve assembly includes a vacuum valvemember located below a top cover plate and is thus protectedfrom the atmosphere. First passageways defined in part bya bottom cover plate provide communication between the out-side atmosphere and the lower surface of the valve. Secondpassageways provide communication between the upper surfaceof the valve and the inside of the container. When thepressure in the container is below atmospheric, atmosphericpressure acting on the bottom of the valve lifts the valveand air flows through the first and second passagewaysuntil atmospheric pressure is reached in the tank. Apressure relief valve is mounted for pivotal movement re-lative to an opening providing communication between thepressure in the tank and the first passageways to ventpressure in the tank. The pressure relief valve is protectedfrom the atmosphere by the top cover plate, and in oneembodiment, by the vacuum relief valve.