UV Lamp Replacement: Lamp Service Life and Quartz Sleeve Cleaning
When to replace the lamp, how to clean the quartz sleeve, and how often each maintenance task is performed: summarized from Nuvonic (Hanovia) operation and maintenance manuals.
Maintenance Schedule for Lamp, Sleeve and Sensor
- Lamp: when operating hours expire or when UV intensity drops, whichever comes first. 12,000 hours for low-pressure PQ AF, and 8,000 hours for medium-pressure PH series (4,000 hours on some larger models).
- Quartz sleeve: kept clean; in the PQ AF manual it is cleaned once a year and replaced at 24 months, and in medium-pressure PH series it is replaced at 20,000 hours or 2 years, whichever comes first.
- UV sensor: performance is verified at least every 12 months (PQ AF); on PH series, the UV monitor is recalibrated once a year.
- Wiper: if an optional automatic wiper is installed, service parts are renewed once a year; the PH manual specifies service every 6–12 months.
For reactor sizing and selection see UV system selection, and for series overviews see the UV disinfection systems page.
Lamp Life by Series
Values are taken from the datasheets on the product pages; lamp service life varies by series.
| Series | Lamp type | Lamp life (hours) |
|---|---|---|
| PharmaLine D AF, DO AF H, PQ AF / PQ AF H | Low-pressure amalgam | 12,000 |
| PharmaLine ECO | Low-pressure amalgam | approximately 9,000 |
| PharmaLine DC PH | Medium-pressure | 8,000 (DC PH 250 and 300: 4,000) |
| PureLine PQ AF | Low-pressure amalgam | approximately 12,000 |
| PureLine D AF, DO AF, ECO, PQ AL | Low-pressure | 9,000 – 12,000 |
| PureLine D PH, DC PH, DCD PH, DO PH, PQ EO / IL | Medium-pressure | 8,000 – 9,000 (D PH 0240 and 0300: 4,000) |
| PureLine S PH | Medium-pressure | 8,000 (S PH 0015: 4,000) |
| PureLine AFX | SmartRay | 16,000 nominal |
| ProLine WW IL | Medium-pressure | approximately 12,000 |
| OpenLine OLS | Low-pressure, high-output amalgam | 14,000 |
| SwimLine PQ IL | Medium-pressure | approximately 12,000 |
| SwimLine PH, Splash PH / PQ EO | Medium-pressure | 4,000 – 8,000 / 9,000 |
| UVShield | Medium-pressure | 9,000 |
| RASLine | Medium-pressure | 8,000 – 12,000 (model-dependent) |
| TOCLine ECO | 185 nm low-pressure amalgam | approximately 9,000 |
| UVpro (air, surface, TS immersion) | UVC modules | 12,000 (output performance at 75% plus/minus 5 level); EKB 100: 6,000 |
Lamp life is the period during which UV output remains at an acceptable level; UV intensity decreases as the lamp ages. According to the manual, the lamp is sized based on expected end-of-lamp-life performance. Frequent on/off switching affects lamp life: the PQ AF panel triggers a "replace lamp" output when either lamp operating hours or the average daily number of starts exceeds the permitted limit.
Schedule for Low-Pressure and Medium-Pressure Series
| Interval | PureLine PQ AF (low-pressure) | PureLine D PH (medium-pressure) |
|---|---|---|
| Daily | - | Check front panel display |
| 12,000 hours / 8,000 hours or low UV | Replace lamp (12,000 hours) | Replace lamp (8,000 hours) |
| 12 months / annual | Renew wiper service parts and seals; clean sleeve; clean sensor window housing; verify sensor | Clean or replace fan filter; renew wiper service parts and seals; recalibrate UV monitor |
| 24 months / 20,000 hours | Replace quartz sleeve together with seals (24 months) | Replace quartz sleeve together with seals (20,000 hours or 2 years) |
| 3–5 years | - | Replace end-plate O-rings and monitor port seal |
| 5 years | - | Replace surge arrestor (VDR) circuit board |
The schedule is taken from the PureLine PQ AF (190160-0400EN-B) and PureLine D PH (190160-4000EN-A) manuals; for other series, the respective manual governs. For replacement lamps, sleeves and periodic maintenance, see our solutions and Nuvonic pages.
Quartz Sleeve Cleaning: Method by Fouling Type
The sleeve is the hydraulic barrier separating the lamp from the water; if it fouls, light transmission drops and disinfection performance declines.
| Fouling type | Method |
|---|---|
| Light fouling | Wipe exterior with isopropyl alcohol (IPA) on soft paper; finish with a lint-free cloth or acid-free paper; rinse with clean water if possible |
| Heavy fouling | Use an abrasive plastic pad first, followed by IPA and a lint-free cloth; final rinse with clean water |
| Iron and carbonate scale (hard water) | 5% citric acid; then rinse with water, clean with IPA, and finish with a clean water rinse if possible |
| Sleeve that cannot be cleaned | Replace (with new O-rings and seals) |
Handle the sleeve only with cotton or non-marking disposable gloves. Cleaning the sleeve prior to installing a new lamp is recommended. On PH series, the quartz probe tip of the UV monitor is also wiped with alcohol when cleaning the sleeve. For removing and installing the sleeve, the PQ AF manual recommends using a plastic tube smaller than the sleeve inner diameter (25 mm outer diameter) as an internal support and installing new O-rings every time.
Safety and Sequence During Lamp Replacement
- Isolate and lock out power: turn the door isolator to the OFF position and lock it out. The medium-pressure PH manual warns that voltages up to 2000 V may be present in the cabinet and lamp connections, and requires waiting at least 5 minutes after switching off the isolator before opening for access.
- Isolate and drain the reactor (if the sleeve will be removed); ensure no one stands in line with the sleeve while loosening the sleeve compression nut.
- Remove the lamp end cap and disconnect the electrical plug. The lamp may be hot; handle it with gloves or acid-free paper.
- Clean the sleeve (see table above) or replace it if required; renew O-rings and seals.
- Install the new lamp: ensure the amalgam spot is oriented as shown in the manual (facing downward on low-pressure lamps); wipe off any fingerprints with IPA.
- Reinstall the cap and connector, pressurize the line, check for leaks, and start the lamp.
- On PH series: operate the system under normal flow for 24 hours and reset the UV% reading to 100; log every replacement in the maintenance record.
On lines undergoing CIP, the medium-pressure PH manual requires switching the lamp off first, waiting for any active wiper cycle to finish, isolating the cabinet at the isolator, and waiting until the plant cools below 40°C.
When a Low UV Alarm Occurs
| Possible cause | Check | Action |
|---|---|---|
| Deposits on quartz sleeve or sensor window | Sleeve and UV sensor window housing | Clean with alcohol; for heavy fouling use the method above |
| End of lamp life | Lamp operating hours | Replace lamp |
| Low water UV transmittance (UVT) | Flow and UVT meter readings | Review process water quality and pre-treatment |
| Flow rate too high (in dose-paced operation) | Flow reading | Bring flow rate within the specified limit |
In the PH series manual, the default low UV alarm threshold is 70%; on the PQ AF, low dose warnings are triggered according to the thresholds configured in the system. Checking the sleeve and sensor window first when an alarm occurs prevents unnecessary lamp replacement.
Frequently Asked Questions About UV Lamps and Quartz Sleeves
Lamp service life, sleeve cleaning, low UV alarms, mercury and disposal.
How often is a UV lamp replaced?
The interval depends on the series. According to Nuvonic datasheets, it is 12,000 hours on series such as PharmaLine D/PQ/DO, PureLine PQ AF and ProLine WW IL; 14,000 hours on OpenLine OLS; 16,000 hours on PureLine AFX; 9,000 hours on PharmaLine ECO and TOCLine ECO; and 8,000 hours on medium-pressure DC PH, D PH and S PH series (4,000 hours on some larger models). The manuals require the lamp to be replaced when its rated operating hours expire or when a low UV alarm occurs, whichever comes first.
The lamp is lit, but UV intensity dropped — why?
The troubleshooting table in the manual lists three causes: fouling of the quartz sleeve, fouling of the UV sensor window, and lamp age. First, clean the sleeve and sensor window; if intensity remains low, check the lamp operating hours and replace the lamp. If water UVT has dropped (UVT too low warning), the issue lies in the water itself and pre-treatment should be reviewed.
How is the quartz sleeve cleaned?
For light fouling, wipe the exterior with isopropyl alcohol (IPA) using soft paper, finish with a lint-free cloth, and rinse with clean water if possible. For heavy fouling, use an abrasive plastic pad first, followed by IPA. For iron and carbonate scale from hard water, apply 5% citric acid and rinse with water and IPA. A sleeve that cannot be cleaned must be replaced. Touch the sleeve only with cotton or non-marking disposable gloves.
Can I touch the lamp with bare hands?
No. The manuals require that the lamp never be held with bare fingers, and that acid-free paper or cotton/non-marking gloves be used. Any fingerprints must be wiped off with IPA. On a cold lamp, mercury condensing on the inner surface may resemble a fingerprint; this is normal and not a fault. Note that the lamp may be hot when being removed.
What should I do with the old lamp?
UV lamps contain a small amount of mercury (under 250 mg in the PQ AF manual). They must be disposed of in accordance with local regulations; new lamps should be kept in their original packaging until used. In the event of breakage, follow the mercury spill procedure in the manual.
What is done after installing a new lamp?
On medium-pressure PH series, after installing the new lamp, verify that the quartz sleeve is clean, run the system under normal flow for 24 hours, and reset the UV% reading to 100. The lamp reaches full output in approximately 5 minutes. The default threshold for the low UV alarm is 70%. Record every replacement in the maintenance log (Appendix A table of the manual).
Send the make and model of your current instrument to [email protected] — our engineers will propose the equivalent with the same connection and measuring range.
Planning a project? Send us your flow rate, feed water source and target water quality to [email protected] — our engineers will reply with a technical proposal.