Following this preventive maintenance schedule keeps the generator producing nitrogen to specification, protects the carbon molecular sieve (CMS) beds, and keeps the warranty intact. First start-up and commissioning is a separate, one-time process; see Start-Up & Shutdown. Some tasks should be performed by a qualified technician or by South-Tek.
In this guide
Maintenance schedule
| Task | Interval | Details |
|---|---|---|
| Replace filter elements (particulate, coalescing, absorber) | Every 6 months (current units) | Legacy units (serial 63963 or earlier) follow a staggered schedule: particulate every 3 months, coalescing every 6 months, absorber every 12 months. See Filter Maintenance for the procedure and how to confirm your unit's schedule by serial number. |
| Verify the O2 analyzer (if equipped) | Annually | Verify against certified test gas. See How do I verify my analyzer is working correctly? |
| Calibrate the O2 analyzer (if equipped) | As needed | Recalibrate if verification fails, after a PM, or any time purity readings look inconsistent. See Oxygen Analyzer & Sensor Calibration. |
| Check CMS levels and top up as needed | Check annually; top up typically ~36 months | Check the CMS level annually and top up as needed; a top-up is typically required around every 36 months. See How Frequently Should I Measure My CMS Levels and What's the Process? |
| Replace process valves | Every 5 years or 15,000 hours | Contact South-Tek for the specific rebuild kit parts and instructions. |
Routine checks
In addition to the scheduled intervals above, perform these checks regularly to catch problems early:
- Monitor nitrogen purity on the controller and investigate any drop. See Alarms & Troubleshooting.
- Check the filter status and differential pressure on the controller; replace elements when a filter shows Overdue or differential pressure is high.
- Confirm the filter drain traps are cycling and the bowls are not full of water. A plugged drain carries water and oil into the adsorber and permanently damages the media.
- Inspect the inlet filters and confirm there is no moisture present at the final filter (F3). Moisture at F3 means the dryer or upstream filtration is not keeping up and the CMS is at risk; correct the upstream drying before it reaches the bed.
- Do a quick visual and leak check of fittings, tubing, and connections.
CMS levels and bed protection
The carbon molecular sieve is the heart of the generator and lasts 10 or more years under clean, dry conditions. Most early purity problems trace back to the air supply rather than the sieve itself:
- Oil carryover from the compressor is the most common cause of CMS failure. Keep the coalescing filtration in good condition and confirm compressor oil carryover stays very low at the generator inlet.
- Liquid water destroys CMS quickly. Keep the inlet dew point within the unit's specification and make sure no liquid reaches the beds. See Site & Utility Requirements for the air supply specification.
- Check the CMS level annually and top up as needed; plan on a top-up roughly every 36 months. If you find carbon dust in downstream piping or filter housings, contact South-Tek, as bed containment may have failed.
Process valve rebuild
Rebuild all process valves every 5 years or 15,000 hours, whichever comes first. Contact South-Tek for the rebuild kit parts and instructions specific to your unit.
Related Articles
- N2-GEN TS, CS, and S Series — Filter Maintenance
- N2-GEN TS, CS, and S Series — Oxygen Analyzer & Sensor Calibration
- N2-GEN TS, CS, and S Series — Alarms & Troubleshooting
- N2-GEN TS, CS, and S Series — Site & Utility Requirements