Vacuum breaker-pressure release device

Claim 1

A valve for use with an air vent pipe of a storage tank which contains fluids in the liquid phase and in the low pressure vapor phase, the valve opening the pipe when the tank is being filled and emptied while keeping the pipe closed otherwise to permit the liquid fluid in the tank to be drawn off and replenished and prevent the vaporous fluid from escaping, comprising a housing with an interior and an exterior, the housing being securable to the pipe in a manner that the pipe communicates with the interior of the housing; an intake check valve arranged in the housing and operatively communicating with the interior and the exterior thereof, the intake check valve operating in a manner that air is permitted to enter the interior of the housing through the intake check valve while being prevented from leaving the interior of the housing through the intake check valve; and an exhaust check valve arranged in the housing and operatively communicating with the interior and the exterior thereof, the exhaust check valve operating in a manner that gas which exceeds a predetermined threshold pressure is permitted to leave the interior of the housing through the exhaust check valve, while gas of a pressure less than the predetermined threshold pressure is prevented from leaving the interior of the housing through the exhaust check valve and air is prevented from entering the interior of the housing through the exhaust check valve, said housing being a J-shaped one piece member having a first tubular portion bounding a first bore having an axis, a second tubular portion bounding a second bore having an axis which is parallel to the axis of said first bore, and a connecting tubular member bounding a third bore which extends between and communicates said first and second bores with one another, said first tubular member forming in said first bore a connecting opening which communicates with an air vent pipe of a storage tank and an air inlet opening through which air can enter said housing and which is coaxial with said connecting opening, said second tubular member forming in said second bore a gas outlet opening through which gas exceeding threshold pressure can leave said housing and which is formed by a plurality of perforations in a wall of said second tubular member.