Mark Stone delivered a fascinating presentation on the advancements of Storage Tank Integrity. It’s of particular interest to David Mobbs having been a career objective to establish a mechanism for detecting metal loss on the base plates of tanks without the need to “drop the tank”. The industry is well versed with Non-intrusive inspection of vessels and pipework, but Corrosion Mapping of Storage Tanks has always relied on man entry and physical base plate inspection. The industry does not like working in confined spaces and there are moves towards zero-man entry over the lifetime of storage and process vessels.
Mark Stone explained that Storage Tank inspection plays a major role in effective integrity management of Storage Tanks. Historically, inspection of the floor has relied on emptying the tank and personnel entry for cleaning and inspection and that the common method of using MFL is not necessarily the most effective method of determining metal loss.
Sonomatic have developed a range of methods for inspection of Storage Tanks while in-service. This includes the use of traditional shell wall inspection using crawlers coupled with new technology to determine metal loss in the first meter of the tank using multi skip technology deployed around the outer chime of the tank.
The key element of the program is however the use of a robotic cleaning and inspection of the floor. The tool dropped through the tank fluids to the floor and remotely guided by use of sonar. The first part of the program is to understand the level of sludge which is completed by the sonar that is strategically placed around the base of the tank. The tool is then able to remove the sludge and scan the base plates, results are transmitted to a mobile unit outside where the program is supported by statistical analysis. The presentation included a case study of a field application and the detail can be seen on the LB page of the website
There was a good level of discussion around the floor and it was the view of David Mobbs that this process real value is in an “iterative process” where a tank farm operator would screen all the tanks and identify which was detected as the worst. On opening the tank and carrying out full base plate inspection its possible to check the model to see how accurate it is. By the time the 3rd tank is completed its full inspection the model is going to be pretty accurate. For Copy of the Newsletter please click below;