A barrier system for the lubricating oil for the bearings of a centrifugal compressor with labyrinth seals installed in a confined environment, consisting of a disc concentrically rigid with the rotating compressor shaft in the chamber facing the bearing situated on the compressor suction side, in a position between said bearing and the relative suction side labyrinth seal, the disc having an inverted U-shaped rim housing a stator ring rigid with the wall of said chamber and arranged concentric with said shaft, which with said rotating disc forms a small passage continuously fed, and kept filled by the centrifugal effect of said rotating disc, with barrier oil bled from the lubricating oil feed, said stator ring being provided, on that side facing the disc, with a wedge which is inserted into a corresponding cavity in the disc, and with an annular deflector tooth projecting beyond the outer edge of said disc cavity.