The invention concerns a device comprising a base (2) and a door (20), said device having a closed door position in which a circuit (8) of the device comprises a bag comprising two flexible films and connectors of the conveying network, and a press (9) comprising a first she (16) disposed on a front face (5) of said base (2) and a second shed (17) disposed in said door (20); and a hinge system hinging said door (20) relative to said base (2), and disposed only on one side of said door (20) so as to form lateral clearances between said door (20) and said base (2) over the rest of a perimeter of said door (20)