[TR] Nitrogen

[Glenn A. Merrell]

acs25m at swbell.net wrote:
> HI all,
> I worked for the telephone company as a cable splicer for 38 years. We used
> nitrogen tanks all the time for airing up our cables as well as our impact
> tools. I don't know when the practice started but had been around a long
> time when I was still wet behind the ears. Any time we had a truck tire that
> was low we would fill it from one of our nitrogen tanks(We normally carried
> two tanks on each truck in pull out drawers). A normal tire would stay
> inflated longer on the nitrogen than it would on regular compressed air, all
> else being equal. That is not to say that the pressure would never change.
> It would with the outside air temperature as do almost all gasses. The thing
> with nitrogen is that it's not detrimental to the rubber itself since it is
> an inert gas. It also happens that the nitrogen molecules are larger than
> oxygen molecules and therefore don't escape as easily. I know this from
> working with it for almost forty years.
> John R Maneke
>   
Well the atomic sizes see to be fairly close:

Nitrogen is 155 picometers
Oxygen is 152 picometers

 I guess I need to go back to elementary science.
Am I remembering correctly - aren't elements atomic and compounds 
molecular??

Anyone know how porous tire rubber compounds and wheel alloys are??

-- 
Glenn A. Merrell
Chairman, Triumph Stag Club USA (2007-2009)
The best trophies are miles on the odometer, stone chips in the paint, dead bugs on the windshield!