Abstract: A shaft seal for a check valve having a shaft rotatably disposed within a valve housing. The shaft seal is disposed within a recess defined within the interior of the valve housing between a bushing member and the shaft. Disposition of the seal within the recess permits accumulation of foreign matter precipitate to occur without deleterious clogging of the clearances between the shaft and the bushing, thus permitting free rotational movement of the shaft. A plurality of sharp-edged grooves disposed on the surface of the shaft provide a flow path for guiding the foreign matter precipitate into the recess. A flushing fluid opening is provided within the valve housing to permit introduction of a flushing fluid into the body recess.