An enclosure containing an inerting gas and at least one liquid to be discharged. This enclosure comprises at least one orifice positioned in its lower part and a liquid discharging system positioned at the orifice. This liquid discharging system is configured to take up a closed state and an open state in which the system allows the liquid to flow towards the outside of the enclosure and includes at least one element that is elastically deformable depending on the pressure inside the enclosure and, depending on its deformation, controls the open or closed state of the liquid discharging system. This solution makes it possible to achieve simple and automatic regulation of the volume of the liquid in the enclosure, without a sensor. An aircraft including at least one such enclosure is also provided.