QJ23900DE - Quartz - Domed End

This is the QJ23900DE domed-end quartz sleeve, the replacement sleeve used across SITA and Atlas-specification UV disinfection systems built around this sleeve size. WrekinWater lists it under its own part reference so you can order by code rather than trying to match a photo. The domed end distinguishes it from open-ended sleeves used on other system ranges.

Signs your quartz sleeve needs replacing

• The sleeve appears cloudy, hazy or scratched instead of clear.
• There's visible brown or yellow discolouration on the glass.
• Your UV monitor or alarm is triggering despite the lamp still lighting up.
• The sleeve is over 12 months old, the usual UV servicing interval.

The domed end of this sleeve seals the lamp chamber at one end while letting UV light pass through the quartz wall to disinfect the water flowing around it. As the glass scales up or scratches with age, UV transmittance drops even though the lamp itself keeps working and looks fine. Because the sleeve is the only barrier between the lamp and the water, a fouled sleeve is one of the most common reasons a UV system loses effective disinfection without any obvious lamp fault.

WrekinWater stocks parts across major water treatment brands, and this QJ23900DE reference lets you order the correct domed-end sleeve without needing to know every model number your SITA or Atlas system might carry. As a family business rated Excellent on Trustpilot, we'd rather confirm fit with you directly than have the wrong sleeve turn up.

How to replace it

1. Isolate the water supply and drain the UV housing before you start.
2. Undo the retaining nut or union, then withdraw the lamp followed by the old sleeve.
3. Clean any built-up scale or fouling from inside the housing.
4. Fit new O-rings and insert the new QJ23900DE sleeve, domed end first.
5. Refit the lamp, restore power and water supply, and run to drain briefly before use.