[TR] Nitrogen

[acs25m at swbell.net]

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