"RST Engineering" wrote in message
.. .
(a) You can go through the math all day long and still not explain why I
have drained the (hangared) 182 after a particularly humid day or two and
get a tablespoon or two of water in the quick drains.

Dan Luke calculated there could be 14 grams of water in 20 gallons of air.

1 tablespoon = 15 milliliters = 15 grams

(b) You cannot explain why "drain the sumps" is a daily check list event
for both fuel trucks AND airplanes.

(c) You cannot explain why CessBeePipMoo all have drains at the low point
of the fueling system. It would be a hell of a lot cheaper not to have to
put them in there. Somebody somewhere thought it was a good idea.

Water can enter tanks in ways other than condensation.