Every vapor recovery unit writes a story in its operating data. Learning what normal looks like on your unit turns that story into early warnings, catching issues while they are still cheap to fix. This article covers how to build the baseline, which patterns matter, and the weekly five minutes that ties it all together.
The Baseline Week
After commissioning or a major service, capture a week of normal operation: vacuum levels during unloading, pressures between deliveries, temperatures, and recovered volumes. This baseline becomes the reference for everything that follows.
The baseline only works if it is honest, so build it from a representative week rather than a flattering one. A week with normal deliveries, normal weather for the season, and no special events gives the reference that later weeks can actually be compared against. Note the context alongside the numbers — blend, season, throughput — because a summer baseline applied to winter weeks creates false alarms by itself.
Patterns That Matter
Recovery volumes that track deliveries are healthy; recovery that lags while deliveries stay constant suggests something changed in the vapor path. Vacuum that builds slower than baseline points toward a restriction or a pump question. Temperature drift often pairs with cooling or lubrication issues.
The reading discipline is comparing shapes, not single points:
| Signal | Healthy shape | Pattern that asks for attention |
|---|---|---|
| Recovered volume | Tracks delivery volume | Lags while deliveries hold steady |
| Vacuum build-up | Same slope as baseline | Slower to reach the same level |
| Standby pressure | Quiet between deliveries | Creeping upward week over week |
| Operating temperature | Flat at seasonal norm | Same load, slowly rising |
Drift Versus Events
Gradual drift over weeks usually means fouling, filter loading, or seasonal fuel changes. Sudden steps usually mean events: a valve position, a control change, a component trip. Reading the shape of the change narrows the search before anyone opens a panel.
This distinction saves diagnostic hours. A step change on a specific date has a cause with a date — check what happened that day: deliveries, work orders, weather. Drift without a date needs the trend itself: pull the last eight weeks and look where the line bends. Two different shapes, two different searches, and mixing them up is how afternoons get lost.
Making It a Habit
A weekly glance at the curves, five minutes with the unit’s log, is enough. Sites that build this habit consistently report fewer surprises and calmer budgets, because the expensive failures announce themselves quietly in the data first.
Attach the five minutes to something that already happens — the Monday delivery review, the weekly walk-through — and it survives staffing changes. The unit’s own log makes this easy: most platforms already store the curves; the habit is simply looking at them against the baseline page, in the same order, every week.
Frequently Asked Questions
Who on site should own the weekly curve review?
Whoever already reads the log for another reason — the Monday delivery review or the weekly walk-through owner. Attaching the five minutes to an existing habit is what makes it survive; creating a new role to carry it is how it quietly stops. The skill transfers in one session against the baseline page.
How long before a baseline needs rebuilding?
After anything that changes the unit’s character — major service, component replacement, a control setting change, or a seasonal transition that resets vapor behavior. Otherwise the baseline ages well; refresh it annually and after events. The test is whether recent normal weeks sit on the old line. When they sit consistently off it, the unit has moved and the reference should follow.
Can the unit’s own trend screens replace manual baselines?
They carry the data, but the baseline needs context the screen does not hold — delivery pattern, blend, season. Use the platform trends as the source, and keep a one-page baseline note beside them with that context. The combination catches what either alone misses. VOHON supplies vapor recovery units with accessible operating data and commissioning baselines — contact us for units that make this habit easy to keep.