Abstract: The invention relates to a system for dispensing a fluid contained in a flask, said system includes a body intended to be associated with said flask and a plunger tube mounted in an association portion formed on said body, wherein said tube is intended to be submerged in the fluid so as to enable said system to be supplied with fluid to be dispensed, with the association portion including a bore in which a portion of the plunger tube fits, and said bore has an annular projection with a diameter restricted with respect to the diameter of the portion of the tube that is fit, with said projection being formed at the junction between a lower converging portion and an upper diverging portion.