Treat the floor and shell as different scopes
Tank floors and shells have different geometries, access conditions and possible damage patterns. Define the examination objective for each, along with the configuration and preparation. An external shell survey does not establish the condition of the floor or every internal surface.
The tank inspection service includes visual examination, thickness testing and corrosion mapping where suitable. This guidance does not assume specialist floor-scanning equipment or a full-coverage technique beyond the agreed service. Ask what the proposed methods can actually examine.
Use a plate and feature location map
Identify shell courses, plates, floor regions, nozzles and weld references using available drawings or an agreed survey map. Define orientation and a stable datum. Number findings and photographs against that map so the maintenance team can locate them after the inspector leaves.
Where the original plate layout is uncertain, label the surveyed references clearly rather than presenting a reconstructed map as an original drawing. Repairs and replacements should retain their own locations and dates so future measurements can distinguish original material from later work.
Prepare access through the site's work controls
Internal examination may require emptying, cleaning, isolation and confined-space arrangements managed by the responsible site team. The inspection scope does not replace those controls. Plan access windows, lighting, preparation and restoration responsibilities before scheduling examination.
Coatings, deposits and floor obstructions can limit what is seen or measured. Agree where preparation is justified and document areas left concealed. If a region cannot be examined, identify its boundaries rather than recording the entire floor as inspected.
Separate readings, mapped corrosion and findings
A thickness point describes the measured location. A visual corrosion map describes observations over a stated area. Weld examination supplies a different kind of evidence. Keep each result connected to its method, coverage and limitations rather than combining them into an unexplained tank-wide score.
Local pitting may need targeted measurement beyond a regular grid. Report minimum readings and uncertain measurements separately from averages. Accessible-side testing may not resolve the opposite surface or hidden interfaces, and those limits matter when the reviewer considers the damage mechanism.
Build a repair and review package
Group findings by located region and provide the original evidence, proposed review needs and any related repair history. An engineer may need design information, contents, loads and service conditions before assessing significance. A standard such as API 653 or AS 1692 is relevant only where applicable to the tank and agreed scope.
After repair, retain the original map and add the repaired extent and follow-up records. Inspection findings can inform maintenance and engineering decisions; they do not guarantee leak-free service or determine readiness to refill. Those decisions remain with the responsible parties under the applicable requirements.
- Separate floor and shell examination objectives.
- Plate map, orientation and located photograph references.
- Method-specific coverage and concealed areas.
- Local minima, repairs and review status linked to the map.