THE DISCLOSURE ILLUSTRATES A CENTRIFUGAL COMPRESSOR COMPRISING AN INDUCE HUB TELESCOPED OVER AN ADJACENT SHOULDER OF AN IMPELLER HUB. THE INDUCER HUB HAS AN INNER ANNULAR SURFACE WHICH RECEIVES AN ANNULAR RELATIVELY THIN SPLIT RING ELEMENT. WHEN THE COMPRESSOR ROTATES AT HIGH R.P.M''S THE SPLIT RING FRICTIONALLY ENGAGES THE INNER ANNULAR SURFACE OF THE INDUCER HUB TO DAMP VIBRATIONS.