Advanced Aboveground Storage Tank Inspections – In-Service Robotics Tank Inspections
This paper describes the advanced in-service tank inspection methods available for use in the inspection of aboveground storage tanks (AST) in the petroleum and petrochemical industry. ASTs are subject to several federal and state regulations requiring tank owners to perform tank floor/bottom integrity, seals system, and deck fittings inspections on a routine basis. The conventional procedure for this type of inspection requires tank owners to drain the tank and clean it with water or solvents, empty sludge residue, and manually inspect the tank. The impacts associated with draining and cleaning the tank, temporarily storing tank contents, waste disposal, excessive emissions, safety hazards, human subjectivity, inaccessibility and inaccuracy, and operational downtime make this procedure inherently a safety risk and undesirable for environmental and economic reasons. Advanced robotics technologies for tank inspections, which do not require taking a tank out-ofservice, are commercially available through several vendors. The robotics technologies use a remotely operated robotic inspection vehicle submerged in the tank liquid for tank floor/bottom and primary seal inspections. The remotely-operated high-resolution cameras are used from the tank top for the deck fittings and secondary seal inspections. The major advantages of using the robotic technologies over the conventional methods of performing tank inspections are improved safety, reduced environmental impact, enhanced quality, and reduced costs.