Ask three sites how often their vapor recovery unit is serviced and you will often hear three answers, none of them written down. The honest response is that intervals follow duty, not habit. Two identical units on different sites can deserve different schedules, because throughput, fuel mix, climate and unloading rhythm all feed the wear rate. The schedule that works is built from the unit data, then adjusted by what the logs actually show.
What the duty decides before the calendar does
Servicing intervals in the equipment documentation assume a reference duty, and the reference is almost never a busy urban terminal. A unit handling heavy seasonal throughput, dusty air or frequent unloading pulses works harder per hour and should be looked at more often. Conversely, a unit loafing through quiet months can stretch intervals with confidence, provided someone is actually watching the indicators between visits. Duty first, calendar second.
The layers of a realistic servicing schedule
Most sites converge on three layers, each with its own owner and depth.
| Layer | Who does it | Typical content |
|---|---|---|
| Operator checks | Site staff on rotation | Alarms, run times, visible leaks, odd noise |
| Routine servicing | Maintenance visit | Filters, seals, sensors, vacuum performance |
| Major overhaul | Specialist workshop | Pump internals, bearings, full teardown review |
The operator layer is the cheapest and the most neglected. Five minutes of looking at run times and listening at the skid catches more developing faults than any quarterly visit, because the people on site hear the change first.
Signals that should pull the next visit forward
- Run times stretching after unloading without a change in throughput;
- Vacuum readings drifting from the values recorded at commissioning;
- New noise, vibration or heat at the pump that was not there last month;
- Alarm codes repeating, even when they clear themselves;
- Fuel or condensate found where it should not be, anywhere on the skid.
Building the schedule into site routine
The sites with the steadiest equipment treat servicing as a fixture: dates in the maintenance calendar, checklists signed and filed, and readings recorded at every visit so the next one starts from data rather than memory. A unit whose history is on paper negotiates warranty questions easily and sells with the site. A unit whose history lives in staff turnover argues every time.
Frequently asked questions
Can servicing be stretched in quiet seasons?
Within limits, yes, if the indicator logs stay clean. Quiet duty wears the unit slowly, and the schedule can follow the load. What cannot stretch is the operator layer, because that is what makes stretching safe.
Does the manufacturer interval override everything?
The stated interval is a floor for warranty purposes and a starting point, not a ceiling for judgment. Hard duty shortens it; easy duty may justify modest stretching, documented, with the manufacturer informed where the contract requires it.
What single habit improves servicing outcomes most?
Writing readings down at every visit, however routine. Trends, not snapshots, reveal the bearing going dry and the vacuum slowly sagging, and trends are only visible to sites that record the numbers.
Luoyang Wohong Petrochemical Equipment Co., Ltd. designs and manufactures vapor recovery units, membrane separation skids and condensers for fuel depots, terminals and retail sites. Contact us for duty assessment and equipment selection support.