A discharge and purging device (10; 110; 210; 308; 408; 410), adapted for limiting the pressure of a fluid occupying the inner volume of a connecting endpiece (2; 102; 202; 303; 402; 403) connected to a duct and allowing lowering of the residual pressure of this fluid upon coupling, the device comprising: - a valve or a valve actuation piston, - an inner enclosure opening out on a front face of the valve or of the valve actuation piston, this front face being intended for cooperating with a valve actuation piston or a valve of an additional connecting endpiece (3; 302; 403; 402), and - an obturator (60; 160; 260; 360) moveable in translation (T1; T2) in the enclosure along a central axis between: - a closed position where the obturator obturates the front face of the enclosure at a first seal area (Z92: Z292) defining a first seal section (S92: S292) located on the side of the front face and - an open position where the obturator no longer obturates the front face, characterized in that the device (10; 110; 210; 308; 408; 410) also comprises: - a first chamber defined when the obturator (60; 160; 260; 360) is in its closed position, between walls (31, 84) of the enclosure, the obturator (60; 160; 260; 360), the first seal area (Z92, Z292) and a second seal area define a second seal section located opposite the front face relatively to the first seal area (Z92; Z292), - a communication passage between this first chamber and the inner volume of the connecting endpiece (2: 102; 202; 303; 402; 403), - means for returning the obturator to its closed position, and - a second chamber defined between walls (31, 37, 38, 39) of the enclosure, the second seal area and the obturator (60; 160; 260; 360) this second chamber being isolated from the inner volume of the connecting endpiece and from the first chamber, and in that the first seal section (S92; S292) is smaller than the second seal section. - a valve or a valve actuation piston, - an inner enclosure opening out on a front face of the valve or of the valve actuation piston, this front face being intended for cooperating with a valve actuation piston or a valve of an additional connecting endpiece (3; 302; 403; 402), and - an obturator (60; 160; 260; 360) moveable in translation (T1; T2) in the enclosure along a central axis between: - a closed position where the obturator obturates the front face of the enclosure at a first seal area (Z92: Z292) defining a first seal section (S92: S292) located on the side of the front face and - an open position where the obturator no longer obturates the front face, characterized in that the device (10; 110; 210; 308; 408; 410) also comprises: - a closed position where the obturator obturates the front face of the enclosure at a first seal area (Z92: Z292) defining a first seal section (S92: S292) located on the side of the front face and - an open position where the obturator no longer obturates the front face, characterized in that the device (10; 110; 210; 308; 408; 410) also comprises: - a first chamber defined when the obturator (60; 160; 260; 360) is in its closed position, between walls (31, 84) of the enclosure, the obturator (60; 160; 260; 360), the first seal area (Z92, Z292) and a second seal area define a second seal section located opposite the front face relatively to the first seal area (Z92; Z292), - a communication passage between this first chamber and the inner volume of the connecting endpiece (2: 102; 202; 303; 402; 403), - means for returning the obturator to its closed position, and - a second chamber defined between walls (31, 37, 38, 39) of the enclosure, the second seal area and the obturator (60; 160; 260; 360) this second chamber being isolated from the inner volume of the connecting endpiece and from the first chamber,