The system has a closing unit (12) associated to a managing tank (6) and movable between a position in which the corresponding tank is insulated fluidically from a managing line (7) and another position in which the corresponding tank is connected fluidically to the line. A transport module is positioned in a preparing and/or managing unit, where the preparing and/or managing unit comprises a control unit arranged to control displacement of the closing unit associated to the managing tank between the positions.
