Ball bearing for the wiper bearing housing on Hanovia medium-pressure ultraviolet disinfection systems. The bearing housing carries the wiper drive shaft where it enters the chamber end; the bearing is what lets the shaft turn freely under the drive load. The quartz sleeve is the only optical path between the lamp and the water, so any film of scale or iron on its outer surface cuts the delivered UV dose. The wiper sweeps the sleeve on a timed cycle to keep transmission at the design figure. A dry or notchy bearing is a common cause of a wiper that stalls or draws excess motor current. Replaced together with the housing O-ring and retaining ring, which are separate items in this catalogue. Reference number 2266A-0103.