Re: [VAL] Nitrogen doesn't expand when heated?

[Dick Kenan <as5368@xxxxxxxxxxxxxx>]

         Water vapor is a gas, like nitrogen.  It expands and contracts 
with temperature, like all gases.  The fact that the nitrogen used by 
racers is dry is, indeed, important, but the water vapor has little effect 
on the expansion.
         Neither water vapor or nitrogen are ideal gases, but for practical 
purposes in tire inflation, they are close enough.  Nitrogen, of course, 
cannot condense upon cooling to ordinary ambient temperatures, and is 
relatively inert.  It's possible that the water vapor may interact somewhat 
with the tire interior.  But, it's expansion/contraction properties are 
very similar to those of nitrogen and of ordinary air.

- Dick
(5368)