API 653 STORAGE TANK INSPECTION
Above-ground storage tank inspection, fitness-for-service assessment, and remote tank integrity engineering by a certified API 653 inspector. Available in Alberta and by remote engineering services worldwide.
API 653 Above-Ground Storage Tank Inspection
API 653 governs in-service inspection, repair, alteration, and reconstruction of above-ground storage tanks built to API 650, API 620, or API 12C. It defines inspection methods, inspection intervals, fitness-for-service assessment, and inspector qualification requirements.
Western Canada has some of the largest concentrations of above-ground storage tank infrastructure in North America. The Edmonton Industrial Heartland, the Hardisty terminal complex, and oil sands upgrader facilities at Fort McMurray represent enormous tankage assets. These tanks require systematic API 653 inspection to maintain integrity and satisfy operator integrity management programs.
A significant portion of API 653 work is calculation-based and does not require on-site presence. Shell minimum thickness calculations, fitness-for-service assessments per API 579, and inspection interval determinations are engineering desk exercises performed remotely using field data. For operators with in-house inspection teams, remote engineering assessment and signed report preparation is an efficient and cost-effective delivery model.
What's Included
- -In-service external inspection per API 653 including shell, roof, settlement assessment, and external coating condition
- -Internal inspection coordination and execution: floor plate scanning, shell thickness grids, floor-to-shell junction, internal lining assessment
- -Corrosion rate calculations and inspection interval determinations per API 653 Section 6
- -Minimum thickness calculations for shell courses and retirement thickness assessment
- -Fitness-for-service evaluation per API 579 for shell thinning and floor plate corrosion
- -Remote tank integrity engineering: FFS assessments and interval calculations from client-supplied UT data
- -Risk-based inspection (RBI) assessment per API 653 Section 6.5 and API 581
- -Inspection report preparation with all required API 653 calculations and interval recommendations
- -Coordination with AMPP Level 2 coating inspection for internal lining and external coating assessment
Inspection Types Under API 653
External Inspection (In-Service)
Conducted without tank entry while the tank remains in service. Shell condition, external coating, roof condition, settlement assessment, and nozzle condition. Maximum interval: 5 years.
Internal Inspection
Requires tank decommissioning and entry. Floor plate scanning, shell thickness grids, floor-to-shell junction, internal coating and lining, and nozzle internals. The comprehensive inspection that drives fitness-for-service determination.
UT Thickness Survey (In-Service)
Ultrasonic thickness measurement of shell without tank entry. Used to calculate corrosion rates and short-term remaining life between full internal inspections.
Risk-Based Inspection (RBI)
Per API 653 Section 6.5 and API 581: probability and consequence assessment that adjusts inspection intervals based on individual tank risk profile. RBI can extend or compress prescriptive intervals.
FAQ
What is the maximum internal inspection interval under API 653?
API 653 sets a prescriptive maximum internal inspection interval of 20 years for tanks with established corrosion rate data, or 10 years for the first internal inspection of a new tank without a measured corrosion rate. The calculated interval based on remaining corrosion allowance and measured corrosion rate may be shorter than these maximums. External inspections are required at a maximum interval of 5 years, independent of the internal interval.
Can API 653 engineering assessments be done remotely?
Yes. Inspection interval calculations, minimum thickness assessments, fitness-for-service evaluations, and full API 653 inspection report preparation are desk-based engineering activities that do not require on-site presence. When client inspection teams supply ultrasonic thickness data and visual inspection records, Norman QC prepares the complete engineering assessment and signed API 653 report remotely.
What is the difference between API 653 and API 510 for tanks?
API 510 covers in-service inspection of pressure vessels operating above 15 psig. API 653 covers atmospheric and low-pressure above-ground storage tanks built to API 650 or similar tank standards. Tanks at oil terminals and tank farms in Edmonton and Western Canada are generally API 653 scope. Pressure vessels at processing facilities are API 510 scope.
Is API 653 inspection required by regulation in Alberta?
ABSA regulates pressure equipment in Alberta. Atmospheric storage tanks built to API 650 are generally not ABSA-regulated pressure vessels. However, many operators mandate API 653 inspection through internal integrity management programs, and pipeline operators may be subject to NEB or CEPA regulatory requirements that include tank inspection.
NEED API 653 STORAGE TANK INSPECTION?
Contact for a scope discussion and fee estimate. On-site inspection in Alberta and remote engineering assessment for operators across Western Canada and internationally.