A disposable set (5) for establishing a fluid connection between a fluid dispensing unit (17) and a dosing device adapted to dispense the fluid into a patients' vein, the disposable set comprising a length of a tubing (15) for establishing a fluid connection from the fluid dispensing unit towards and into the dosing device, wherein the tubing (15) comprises a first (1) and a second (10) tubing part, and a releasable connection (11,12), wherein the first tubing part (1) comprises two or more one-way valves (3, 24) which are provided to prevent a backflow from the patient in the direction of the fluid dispensing unit (17) in the closed position of the releasable connection.
