API 653 and Storage Tank Inspection 2

[Carmagen]

API 653 provides the owner-user a fair amount of latitude re: the extent of inspection that is done on aboveground atmospheric storage tanks. I'm curious how folks have used their local experience to come up with the extent of inspection that is actually done on particular tank shells and bottoms, and how they prioritize which tanks are inspected and when. Any info. that could be shared would be appreciated. Thanks.

 

[jeffcoat]

You are very correct that both API-653 (Also API-510, & API-570) and the OSHA & EPA codes allow a lot of latitude for certain parts of the inspections.&nbsp;&nbsp;They must, however, be defensible and governed by &quot;generally accepted good engineering practice&quot;&nbsp;&nbsp;The extent of the inspection should depend on variable such as operating conditions, product, consequence of failure, etc.&nbsp;&nbsp;<br><br>Also the results of the inspection need to be evaluated by a competent engineer experienced in the design of storage tanks (or pressure vessels or piping, given the situation)<br><br>It has been my experience that many companies simply hire an API-653 inspection, and no thorough evaluation is performed.&nbsp;&nbsp;<br><br>Unfortunately, I'm not sure whether I can leave me email address or my company's web site to give you more information

 

[mduncan]

For companies we have worked for, they decide what is considered a covered process. Then they determine a priority based on a lot of factors. When was the last inspection? Has this tank had a history of failures? What is the process. <br><br>As far as priority based on internals, one suggestion would to perform externals on the shells and roof. Pay particular attention to the bottom shell course, external ring and sump area for signs of corrosion. Then set a priority based on the corrosion rates of these components.<br><br>An alternative would be looking into accoustic emmissions?