A Sterilight/Viqua quartz glass sleeve protects the lamp from water that flows through the Viqua stainless steel chamber. The ability of the UV light to pass through the quartz glass sleeve into the water creates the Ultraviolet germicidal irradiation (disinfection) of air and water. O-rings are necessary for a water-tight seal at each end of the quartz sleeve. O-rings ship with your quartz sleeve and should be replaced when the bulb is changed, and/or checked regularly for wear.
Quartz Sleeve replacement/maintenance: Minerals in the water slowly form a coating on the quartz sleeve. This coating must be removed because it reduces the amount of UV light reaching the water, thereby reducing disinfection performance. If the quartz sleeve cannot be cleaned, it must be replaced. When UV systems are left on for long periods of time without water flow, the quartz sleeve becomes less translucent faster and may need to be cleaned more often. Sterilight recommends a minimum 75% UVT rating.