"Rod McInnis" wrote in message ...
"basskisser" wrote in message
om...


Again, unless introduced under ideal conditions, there WILL be water
vapor.

Key word "vapor". It obeys the ideal gas law as long as you stay away from
the condesation points.

If you had inflated the tire from an air compressor that included a storage
tank then the air had originally been at a much higher pressure. The higher
pressure increases the "dew point" considerably which usually results in
water condensing in the tank of the air compressor. A high quality air
compressor will provide for an automatic water drain, cheaper units simply
provide a drain valve at the bottom. Either way, the air that travels down
the air hose ends up drier than the air that was originally pumped into the
tank.

Assuming that you aren't pumping your trailer tires up to a couple hundred
PSI, the air in the tires will be significantly less than the air in the
storage tank was. At the lower pressure, the dew point will be
significantly higher, making it much less likely that you will condense any
of the vapor back into liquid.

You could create a sceanario where you could end up with enough water vapor
pumped into the tire so that at some realistic temperature there would be
enough condensation to create a measurable change in pressure. If a fraction
of a PSI matters that much to you then it would be trivial to avoid such a
sceanario at far less cost than dealing with nitrogen.

Which gas are you saying doesn't obey the gas laws: air or nitrogen?

Niether.


This is an interesting statement. Are you saying that the ideal gas laws
are wrong, or that for some reason nitrogen is not an ideal gas? Do you
think there are no ideal gases at all?

Nope, never said either. And I never said that either air, or nitrogen
"doesn't obey the gas laws."

The condensation point for nitrogen at any reasonable pressure is damn cold!
The rubber on the tire will get hard and brittle long before you got
anywhere close to the condensation point of nitrogen!

That has absolutely nothing to do with the fact that that nitrogen
doesn't expand at the same rate as oxygen for any given temperature
change. Do you deny this?

Your understanding of thermodynamics is simply wrong!
Do a web search on "ideal gas" or "PV=nRT" or "boyles law". There are
plenty of sites from major universities that will educate you on this.

Rod

No, it's not. You simply don't understand my position.