Abstract: A non-return valve with twin plugs is connected to a fluid reservoir and equipment that can receive a small overflow quantity essentially in the gaseous state from the reservoir. This occurs when the primary valve is open. In the case of a larger overflow essentially in the liquid state, the openings are switched over to evacuate the overflow to another outlet branch of the non-return valve, without it being transferred to the equipment. The invention is useful in an oil lubrication circuit, in which a hypothetical fuel leak into the oil could cause the oil reservoir to overflow into the non-return valve and in which a significant flow of liquid to the equipment must be avoided; oil outlet through the other branch of the outlet can remain in a reservoir provided with a drain system.

Abstract: A non-return valve with twin plugs is connected to a fluid reservoir and equipment that can receive a small overflow quantity essentially in the gaseous state from the reservoir. This occurs when the primary valve is open. In the case of a larger overflow essentially in the liquid state, the openings are switched over to evacuate the overflow to another outlet branch of the non-return valve, without it being transferred to the equipment. The invention is useful in an oil lubrication circuit, in which a hypothetical fuel leak into the oil could cause the oil reservoir to overflow into the non-return valve and in which a significant flow of liquid to the equipment must be avoided; oil outlet through the other branch of the outlet can remain in a reservoir provided with a drain system.