aemeijers wrote:

I can understand that on tanks exposed to weather or ground moisture, but a
basement tank? (Assuming a dry basement, of course.) As long as outside
shows no signs of rust, I'd think a borescope inspection of interior every
five years or so (I assume these things have a bunghole?) would be more than
adequate. I know the pickup tube isn't on the bottom, but as long as no rust
flakes are visible in the drained sludge, what are the odds of major
interior rustout with no outside evidence?

There can (and often is) moisture in a fuel oil tank. There are two
outcomes. One is the tank rusts. The other is microbes that grow in the
area between the oil and water and feast on the oil since oil is
slightly hygroscopic causing "goo" which blocks equipment.

(Having said that, any interior tank should of course have a spill berm
around it, or be sitting in one of those giant kitty litter pans.)

aem sends...



All (new/replacement) interior tanks have been double wall for some time.