Plastic washer for the wiper bearing housing on Hanovia medium-pressure ultraviolet disinfection systems. It sets the running clearance in the housing and keeps the bearing off the adjacent metal face. One of the bearing-housing consumables — bearing, O-ring, stainless retaining ring and this washer — replaced as a set when the housing is opened. Also catalogued against the bearing housing assembly reference 2279J. Reference number 2266B-0103.