Tank Inspection Services in Denver 2026 — ASNT Level III Led

Storage tank inspection around Denver: cold-weather brittle fracture, floors and the inspection cycle

Aboveground storage tanks around Denver are inspected to API 653 when they are field-erected and usually to STI SP001 when they are shop-built, with intervals set by measured corrosion rates. Atlantis performs the NDE for the owner's program: MFL floor scanning, UT shell thickness, vacuum box testing of welds and settlement data. The owner's API 653 inspector signs the inspection; Atlantis never signs as inspector of record.

Cold weather and brittle fracture. API 653 includes a brittle fracture assessment for tanks that change service, are repaired or altered, or operate at low metal temperatures. Denver winters regularly bring hard freezes, so older tanks built before modern toughness requirements need that assessment on file before a change of service or a major repair. The assessment depends on the shell thickness, material and history the NDE supplies, so thickness surveys and records of earlier repairs should be complete before the engineer starts.

What the Front Range climate does to tanks.

• Strong sun and altitude break down shell and roof coatings faster on the south and west faces
• Snow and ice load fixed roofs and wind girders, and freeze in floating-roof drains if they are not kept clear
• Freeze-thaw cycles crack foundation rings and open the chime area to water
• Large daily temperature swings work rim seals and nozzle connections loose over time

Each of these shows up first in the external inspection, which API 653 requires at intervals of no more than five years, or sooner where the corrosion rate demands it, with ultrasonic shell thickness surveys on their own corrosion-rate-based cycle. The internal inspection, with the floor scanned by MFL and indications proved up by UT, is what sets the next out-of-service date.

Which rules apply. Facilities above the federal oil storage thresholds need a Spill Prevention, Control and Countermeasure plan under 40 CFR Part 112, and the plan commits the owner to inspect and test tanks to an industry standard such as API 653 or STI SP001. Colorado has no OSHA State Plan, so for tanks inside a process covered by process safety management, the federal standard is the one that applies. Owners should also check with the Division of Oil and Public Safety, which already handles Colorado's boiler program, for any state storage tank requirements that sit alongside the federal rules.

How the work is split. The owner's program sets the scope and intervals, the owner's API 653 inspector evaluates the data and signs, and Atlantis supplies the examinations, the data review and a report that ties every reading to a fixed location on the tank. The API 653 tank NDE support page sets out that division of responsibility.

Service detail is on the aboveground storage tank inspection and MFL tank floor inspection pages, with vacuum box and other checks under leak testing. Thickness data is only useful as a trend when each reading lands on the same location every campaign, which is what Atlantis ERP keeps. To plan a tank campaign, send the tank list, diameters, products and outage dates through the Denver tank inspection request.