Storage Tank

A storage tank is a low-pressure, large-volume welded container for the storage of liquids — typically atmospheric (API 650), low pressure (API 620), or for water (AWWA D100) — inspected in service per API 653.

Definition

Storage tanks are subject to bottom corrosion (interior and underside soil-side), shell corrosion, roof leaks, settlement, and seismic damage. Internal inspection requires shutdown, cleaning, gas-freeing, and MFL floor scanning per API 653.

Related terms

  • API 650 Welded Tanks for Oil Storage — API 650 is the construction code for welded steel atmospheric storage tanks, defining materials, design, fabrication, welding, examination, and testing requirements for new tank construction.
  • API 653 Tank Inspection, Repair, Alteration, and Reconstruction — API 653 is the inspection, repair, alteration, and reconstruction code for above-ground welded steel storage tanks built to API 650, defining periodic external (5 yr), ultrasonic (10 yr), and internal (typically 10 yr) inspection intervals.
  • Pressure Vessel — A pressure vessel is a closed container designed to hold gases or liquids at a pressure substantially different from ambient, typically constructed per ASME Section VIII and inspected in service per API 510.
  • Magnetic Flux Leakage (MFL) — MFL is an electromagnetic NDT method that magnetizes a ferromagnetic component to saturation and detects flux leakage at metal-loss features using Hall-effect or coil sensors, widely used for tank-floor and pipeline pig inspection.

Further reading

storage tank floor scanning mfl vs ut comparison

More asset-type terms

Heat Exchanger · Fired Heater · Pipeline · FPSO · Riser · Jacket · Topsides · Wellhead · Christmas Tree · Blow-Out Preventer

Where this comes up in practice

Terms like this one appear in three places that matter commercially: the written practice that governs how your personnel are qualified, the procedures and technique sheets that define how an examination is actually performed, and the evidence an auditor or client asks for when they want to know why an inspection was accepted. Getting the terminology right is the easy part; being able to produce the qualification record, the calibration traceability and the procedure revision that applied on the day of the inspection is the part that decides audits.

Atlantis NDT provides NDT training and certification against ASNT SNT-TC-1A and ISO 9712, ASNT Level III consulting for written practices and procedure approval, inspection management software that holds qualification, calibration and procedure-revision evidence in recoverable form, and an asset integrity platform that binds inspection results to the asset they describe. Browse the full NDT glossary or ask a Level III directly.