Posted by Jeff Wahl on 1/29/2020 to
UV System Education
An often overlooked or unknown component of a UV system is the quartz sleeve / dome. It’s purpose is to act as a protective shield, preventing water from coming in contact with the electrically charged UV lamp. Quartz sleeves are located within the stainless steel chamber that is part of most residential and commercial UV systems.
The Importance for UV Disinfection
A UV Lamp emits 360 degree rays through the quartz sleeve within the UV chamber to disinfect water. Water quality can have an impact on your sleeve and result in it becoming fouled with dirt, scaling, stains or scratches. Coarse sediment can result in pitting or etching of the quartz sleeve exterior surface. Fouling and etching can refract the UV rays and prevent them from reaching the water in the proper strength to disinfect properly. In some cases the sleeve is severely fouled with contaminants such as iron or sulphur and the rays do not reach the water at all. This prevents disinfection of the water and there are no warning or indicators indicated by most residential UV systems.
Cleaning, Handling and Care
Residual oils from skin will remain on the outer surface of the sleeve. Gloves should be worn at all times when handling quartz sleeves to prevent transfer of oils to the exterior of the sleeve. Care should also be taken not to allow any water into the center of the sleeve. You should never have to clean the inside of the sleeve as the water flows on the outside. Cracks, especially at the top of the sleeve are a potential flood risk and it should be replaced immediately. Clean using a soft pad with a commercially available scale remover such as Lime-Away or CLR and always ensure that you do not allow cleaner or water to enter the center of the sleeve.
Tips & Tricks
Visual perception is important, place the sleeve against a white sheet of paper to ensure it’s transparency. It should be clear and if it seems discolored after cleaning; replace it.
Cleaning Frequency
Proper pre-treatment of water for hardness, scaling, iron, sulphur or particulate will result in less frequent cleaning. Be sure to clean the sleeve with every UV lamp replacement. After your system is installed, it is a good rule to check the sleeve for fouling after three months operation. If you are noticing discoloration, scaling or coating of the surface, it will need to be cleaned more frequently. If this is the case, you should have your water tested to determine the source of the problem and identify what is required to prevent it from occurring. If you have to clean your sleeve on a regular basis, it is not working properly.
Water Quality Requirements
All manufacturers indicate the water quality operating requirements for their systems which are designed to ensure that the system operates properly. These are the most common:
Replacing the O-Ring
To ensure that there is a water tight seal and prevent water from entering the sleeve or escaping the UV chamber, an o-ring is used. This is located at the top of the open end of the sleeve or at both ends if it is a double ended open sleeve. The o-ring(s) should be replaced annually with every UV lamp replacement. Heat generated from the normal operation of UV systems can deteriorate o-rings over prolonged periods of time, causing lamp failures from water entering the sleeve or flooding from water leaving the UV chamber. O-rings are typically shipped in the packaging for all new quartz sleeves and UV lamps.
Tips & Tricks
Do not use any vaseline or silicone based lubricants on the o-ring.
Discard all old or used o-rings are they can dry out or become cracked.
Keep a spare set of o-rings on hand in case of emergencies.
Replacement Intervals
Manufacturers recommend replacing the sleeve every 24 to 36 months depending on water quality. Based on my experience, a good practice is for 24 month replacements. This will help to provide a clear path through the sleeve for UV rays to disinfect water. It is important to note that frequent cleaning can leave residuals behind, and it is recommended to follow your manufacturer’s suggested change intervals.
Best Practice Recommendation
Proper replacement intervals, maintenance and cleaning of quartz sleeves is critical to ensure uninterrupted bacterial disinfection 365 days a year. If you are unsure, replace the quartz sleeve and have the water tested properly for hardness, iron, tannin, sulphur and transmittance. If bacteria is present in your water, you do not want to take a chance with a fouled UV sleeve that could compromise the water safety in your home, business or cottage.
Volume 4 – Issue 1 Wahl H2O - Water Awareness
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