Abstract: The circuit includes an internal volume for receiving a cooling fluid, a stopper for selectively closing an opening giving access to the internal volume, and ensuring element that the cooling fluid can be discharged via a discharge outlet. The respective discharge and access openings to the internal volume are distinct from each other, and a flap valve, which is detachably fixed in relation to the stopper and which is moveable between respective closure and release positions of the access opening when the flap valve is disconnected from the stopper, is also provided. The flap valve exclusively moves from its closed position when the pressure prevailing inside the internal volume is lower than a predefined pressure value.

Abstract: The circuit includes an internal volume for receiving a cooling fluid, a stopper for selectively closing an opening giving access to the internal volume, and ensuring element that the cooling fluid can be discharged via a discharge outlet. The respective discharge and access openings to the internal volume are distinct from each other, and a flap valve, which is detachably fixed in relation to the stopper and which is moveable between respective closure and release positions of the access opening when the flap valve is disconnected from the stopper, is also provided. The flap valve exclusively moves from its closed position when the pressure prevailing inside the internal volume is lower than a predefined pressure value.