What is an API-653 inspection?
An API-653 inspection is an inspection defined in the API-653 document maintained by the API (American Petroleum Institute). API-653 covers “Tank Inspection, Repair, Alteration, and Reconstruction” for larger Above-ground Storage Tanks (ASTs). Two types of inspections are defined in API-653: In-service and Out-of-service.
An In-service inspection covers everything on the outside of the tank. Basically everything on the outside of the tank can be reached from outside the tank. So in a traditional API-653 inspection this can be done while the tank is “in-service”.
An Out-of-service inspection is what can only be done from inside the tank. Typically the inspection includes the tank floor and a visual of the inside of the tank. The out-of-service inspection is done when the tank is “out-of-service”. This inspection requires draining, cleaning, and degassing the tank.
In contrast, our company Manta Robotics, uses robots that can safely go in fuels. We perform the visual inspection of the inside of the tank and inspect the tank floor with liquid in the tank. This allows our inspection team to perform the Out-of-service inspection while the tank remains in-service.
What type of tank requires an API-653 inspection?
There are two standards used to inspect Above-ground Storage Tanks (ASTs). The standards are API-653 and SP001 (Steel Tank Institute standard). While API-653 does not specify any size requirement it generally applies to field erected tanks constructed to the API-650 standard. In addition SP001 states that SP001 only applies to tanks less than 50ft tall and less than 30ft in diameter. Ultimately the standard chosen to be used to inspect an AST should be determined by the PE responsible for the tank. For some guidance in this respect refer to the SPCC Bulk Container Fact Sheet.
How often does this inspection need to be performed?
Typically an AST needs to be inspected every 10 years for an internal inspection and every 5 years for an external inspection. The history of the tank can affect this period and require the inspections to be performed at shorter intervals. Previous API-653 inspections are a factor for determining this time period. The API-653 section 6.4.2 describes this inspection interval and how it is determined.
Is a robotic in-service inspection of the tank floor an approved method?
Yes! In API-653 section 22.214.171.124 robotic inspection is specifically called out as a method that can be used to inspect the tank floor while the tank is full and in-service.
How do I find out more?
Contact us on our contact page.