Why Maintenance Determines Recovery Performance
A 3-stage vapor recovery unit only delivers its rated efficiency when it is maintained. Dirty heat exchangers, leaking seals, and mis-calibrated sensors quietly reduce recovery performance while energy costs stay the same – or rise. A simple preventive maintenance program protects the investment and keeps the site compliant.
Daily and Weekly Checks
- Visually inspect the unit for oil leaks, unusual vibration, or abnormal noise from the compressor and fans.
- Check control panel alarms and log readings: inlet pressure, discharge temperature, and liquid level in the collector.
- Verify that the vent stack is clear and that no liquid is pooling in vapor lines.
- Record daily operating hours and recovered-liquid volume; a sudden drop signals a problem.
Monthly and Quarterly Tasks
- Heat exchanger inspection: check for frost build-up, fouling, or blocked drain ports. Defrost and clean per the manufacturer’s instructions.
- Compressor service: check oil level and condition, belt tension (if applicable), and discharge pressure.
- Adsorption bed check: monitor bed pressure drop and regeneration cycle timing. Replace adsorbent at the recommended interval or when breakthrough is detected.
- Membrane module care: for condensation-plus-membrane units, check inlet filters and membrane differential pressure; keep the feed clean to protect the membrane and maintain discharge NMHC levels.
- Sensor calibration: verify pressure transmitters and temperature probes against known references.
- Electrical inspection: confirm all explosion-protected enclosures are properly sealed and cable glands are tight.
Common Faults and How to Fix Them
| Symptom | Likely Cause | Action |
| Recovery rate drops | Fouled condenser, low refrigerant charge, or bypassing seals | Clean coils; check refrigerant; inspect valves and gaskets |
| Excessive vibration / noise | Loose mounting, worn bearings, or unbalanced fan | Tighten mounts; replace bearings; balance or replace fan |
| Frequent cycling | Incorrect setpoints or leaking vapor-line valve | Review control settings; repair or replace valve |
| High discharge odor / NMHC rise | Adsorbent saturation, membrane damage, or fouled condenser | Regenerate or replace adsorbent; inspect membrane module; clean condenser |
| Liquid carryover to stack | Blocked demister or overfilled collector | Clean demister; check level control and pump |
Keep a Maintenance Log
Document every inspection, repair, and part replacement. A complete log proves due diligence to inspectors, helps predict spare-part needs, and makes troubleshooting faster when problems occur.
Service Support
Vohon provides commissioning support, operator training, and spare parts for its 3-stage vapor recovery units. Our service team can also audit an existing installation and recommend upgrades that restore or improve recovery performance.