A300Driver

A300Driver

Active Member
At my grass strip we have a 1000 gal, single-walled, above ground avgas tank. The "manager of billing" says we're losing @ 10-15% monthly due to evaporation.

We're in San Antonio - so it's pretty hot but the tank is in the shade (it's covered). Does anyone with "fuel farm" / FBO experience have any ideas, clues or suggestions as to why we're losing so much avgas - or is this normal?!



Thanks,
Bob
 
fuel storage

I worked the fuel line at several GA FBO using 1200 gallon tanker trucks. We never lost any fuel. Fuel was metered in and metered out with daliy records that had to balance. A fuel truck is not much different from above ground tank. Could it be a bookkeeping error? If there are a large number of users who have access its easy to make metering or record keeping mistakes. :D
 
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Someone is helping themselves to some fuel - either officially or unofficially. Even without maintaining any pressure on the tank, no fuel will be lost as long as vapors cannot mix with outside air and escape the tank. The fuel inside will vaporize, the internal free volume of the tank will fill with fuel vapor, and an equilibrium between the vapor and liquid will be reached, based upon vapor pressure and temperature.

Think about it - you'd be losing fuel at the same rate from your wing tanks as well if it really evaporated out like that. I call BS.
 
Thanks

Thanks for everyone's advice and info. I'm hoping this is a simple matter if a meter that needs to be re-calibrated.

Thanks again,
Bob
 
Leak

Hi Bob,
I had a vertical, three thousand gallon tank that I leased to the flying club and the guys got mad at each other because it ran dry pretty quickly. They discovered that it had a leak where it sat on the gravel pad!
Regards,
 
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