Casing system (120, 220, 320) which is intended to be mounted between a supply pipe and a discharge pipe in which a heat exchange fluid circulates, the casing system (120, 220, 320) comprising: - a sealed casing which is divided by a sealed separation wall (234, 334) into a first volume and a second volume which is filled with a gas which is inert with respect to dihydrogen, - a vacuum pump which is connected in fluid terms to the first volume and which is configured, during operation, to generate the make vacuum in the first volume, - an upstream pipe along which an upstream solenoid valve is mounted and which is intended to be connected in fluid terms to a dihydrogen tank, - a downstream pipe along which a downstream solenoid valve is mounted and which is intended to be connected in fluid terms to an engine, - a heat exchanger which is fixed inside the casing through the separation wall (234, 334) and which has a first inlet which is connected in fluid terms to the upstream pipe downstream of the upstream solenoid valve and a first outlet which is connected in fluid terms to the downstream pipe upstream of the downstream solenoid valve and which has a second inlet which is intended to be connected in fluid terms to the supply pipe and a second outlet which is intended to be connected in fluid terms to the discharge pipe, wherein the first inlet is arranged in the first volume and the first outlet is arranged in the second volume, - a first pressure sensor which is arranged in the first volume, - a second pressure sensor which is arranged in the second volume, - a control unit which is arranged to receive pressure values measured by the pressure sensors (224a-b) in order to detect, on the one hand, if the deviation in absolute value between two successive values of the pressure in the first volume is less than a first threshold or greater than a second threshold which is greater than or equal to the first threshold and, on the other hand, if the deviation in absolute value between two successive values of the pressure in the second volume is less than another first threshold or greater than another second threshold which is greater than or equal to the other first threshold, and to close the solenoid valves (122a-b) if it detects a deviation in absolute value between two successive pressure values beyond the second threshold in the first volume or the other second threshold in the second volume. - a sealed casing which is divided by a sealed separation wall (234, 334) into a first volume and a second volume which is filled with a gas which is inert with respect to dihydrogen, - a vacuum pump which is connected in fluid terms to the first volume and which is configured, during operation, to generate the make vacuum in the first volume, - an upstream pipe along which an upstream solenoid valve is mounted and which is intended to be connected in fluid terms to a dihydrogen tank, - a downstream pipe along which a downstream solenoid valve is mounted and which is intended to be connected in fluid terms to an engine, - a heat exchanger which is fixed inside the casing through the separation wall (234, 334) and which has a first inlet which is connected in fluid terms to the upstream pipe downstream of the upstream solenoid valve and a first outlet which is connected in fluid terms to the downstream pipe upstream of the downstream solenoid valve and which has a second inlet which is intended to be connected in fluid terms to the supply pipe and a second outlet which is intended to be connected in fluid terms to the discharge pipe, wherein the first inlet is arranged in the first volume and the first outlet is arranged in the second volume, - a first pressure sensor which is arranged in the first volume, - a second pressure sensor which is arranged in the second volume, - a control unit which is arranged to receive pressure values measured by the pressure sensors (224a-b) in order to detect, on the one hand, if the deviation in absolute value between two successive values of the pressure in the first volume is less than a first threshold or greater than a second threshold which is greater than or equal to the first threshold and, on the other hand, if the deviation in absolute value between two successive values of the pressure in the second volume is less than another first threshold or greater than another second threshold which is greater than or equal to the other first threshold, and to close the solenoid valves (122a-b) if it detects a deviation in absolute value between two successive pressure values beyond the second threshold in the first volume or the other second threshold in the second volume.