We clean and repair most fuel tanks up to about 1K gallons on shore also!
Fuel/Water Interface --->
(*see below please)
(for scale the bottom of this tank is 1/4 inch thick)
Microbiological Growth --->
(*see below please*)
Corrosion is the Pits!
One of the waste products created by biological growth in a diesel tank is sulfuric acid. Being heavier than water, as well as fuel, the acid will settle to the bottom of the pits and will stay there until it is removed or it is neutralized by the chemical reaction of corroding the metal.
As the pitting from corrosion gets deeper the less likely it is to stop without sterilizing, and possibly lining areas of the tank. You can't kill all the bugs by steam cleaning but you can take away their hiding spots (sludge), and then treat the tank with biocide to keep them from coming back.
(microbe waste and debris ---> from fuel degradation)
Emulsified Fuel and Water --->
(Some types of microbes excrete emulsifiers as part of their waste. The result is a layer on top of the growth that looks like strawberry milk.
Water Bottom --->
Good Fuel --->
Clean, dry, usable fuel with no emulsified water.
*Microbiological growth*, algae, bugs, biomass, sludge --- Whatever you call it, it doesn't sound good, does it? And it shouldn't!
The fact is, short of a major structural failure, an infestation of microbiological growth is about the worst thing that can happen to your fuel tank.
The microbes are mostly bacteria and fungi and there is never just one type. They live in cooperative groups with the byproducts from one type helping another type to survive and thrive. There can be many different types in the same fuel tank.
These "consortiums" need two things to survive: fuel for food and a tiny amount of water.
The *Fuel/Water interface* in an infested tank is more of a zone than a line. This is because some of the bugs give off emulsifiers, like soap, and are very good at mixing water into the fuel next to them.
A fuel system with bugs is attacked at every point. Acidic waste eating the tank, the sludge build-up from accelerated degradation of the fuel, and the microbes actually changing the physical and chemical properties of the fuel are all a recipe for a major problems.
Precision Fuel Solutions