Patent ID: 8118051

Claim:
A valve for the ventilation circuit of a liquid tank, comprising: a) a chamber comprising a base, a side wall and an upper wall, the base of the chamber including an apertured plate that comprises openings, the openings in the apertured plate being designed to prevent significant liquid penetration during a rise of a liquid level in the tank, the side wall of the chamber including at least one opening of sufficient size and location for liquid to penetrate into the chamber; b) at least two independent ventilation orifices made in the upper wall of the chamber and connecting the chamber to the venting circuit; c) at least one orifice made in the side wall of the chamber and connecting the chamber to an inside of the tank; and d) at least two independent floats each comprising an apex capable of sealing one of the ventilation orifices, said floats: being located inside the chamber without a partition between the at least two independent floats; being able to slide vertically inside the chamber depending on the liquid level in the chamber and resting, when the chamber is empty, on its base; being calibrated so that one of the floats seals one of the ventilation orifices at one liquid level L1 in the tank and so that the other float seals the other ventilation orifice at a level L2 above L1; and being concentric.