Glenn Ashmore wrote:
"Kurt Krueger" wrote

How about throwing in some dry ice to displace the vapors?


I'm not sure which is heavier but I suspect the gasoline would be heavier so
it might get trapped under the CO2. Then when the CO2 disburses the gas
vapor will still be there.

The gasoline should be heavier (with gases, it is easy - it is all based
on the molecular weight), but even if some gasoline vapors are still in
there, there won't be any air.

And all of this presumes that there is absolutely no turbulence during
the sublimation of the dry ice, so that there is no mixing. Not very
likely. At something like 12 cubic feet of CO2 for each pound of dry
ice, a few pounds of dry ice should provide several tank volumes of CO2,
which would sweep most of the air and gasoline vapors out of the tank,
leaving behind an inert gas filling.

bob