Abstract: Connection systems and connecting methods for transferring fluids. According to one embodiment, the connection system includes an active unit having an active connection assembly connected to a first supply conduit and a passive unit including a passive connection assembly connected to a second supply conduit. The active connection assembly includes a first connector coupled to the first supply conduit, an active sleeve externally coupled to the first connector, and sealing means fixed inside the active sleeve which, in a fluid disconnection position, surrounds the first connector, preventing the outflow of fluid from the first connector. The passive connection assembly includes a second connector connected to a second supply conduit, the active unit including drive means for causing the movement of the active sleeve between the fluid disconnection position and a fluid connection position without axially moving the first and second connectors.