Tire inflation with Nitrogen or ?

So, all jokes aside, what is the reasoning of using Nitrogen? Something
to do with no oxidizing because of lack of O2??? I get many years out
of a set of baloney skins and the tread wears off before they rot out,
so it seems like it would just be added expense. Plus, I believe a tank
of Nitrogen would last 100 lifetimes if all you used it for was to fill
airplane tires.

Scott


Paul Tomblin wrote:

In a previous article, "Maxwell" said:

wrote in message
groups.com...

Michelin recomends inflating tires with nitrogen. What about Argon? I
got a bottle of argon I use in Mig welding aluminum. Isn't argon
better than Nitrogen? What about the common 75% Argon and 25% CO2
welding mixture?


I'm not sure about the other aspects, but nitrogen is about 1/3 the price.


And ordinary compressed air is already 80% nitrogen.



--
Scott
http://corbenflyer.tripod.com/
Gotta Fly or Gonna Die
Building RV-4 (Super Slow Build Version)

Except for those of us that use inner tubes...



Morgans wrote:




Even more important, is the fact that there is no oxygen to cause oxidation
in the metal wheel and to affect the rubber of the tire.

"Maxwell" wrote in message ...
:
: "andrew m. boardman" wrote in message
: ...
: Kyle Boatright wrote:
: I'm not 100% sure what Clare means by "more temperature stable, pressure
: wise.", but all gasses follow Boyle's law, which is Pressure x Volume =
: Number of moles x Avogadro's number x Temperature... PV=NRT.
:
: The problem with a strict gas-law analysis is that a tire filled with
: compressed air has moisture hanging around in both vapor and liquid form;
: the ratio varies with temperature, which makes the math all annoying and
: nonlinear, and worse, variable between tires.
:
: On the other hand, this often gets translated to "nitrogen doesn't expand
: when heated, unlike air" by authors who really ought to know better; this
: is complete crap. The difference is *really* marginal, though cutting
: down on oxidation is much more relevant.
:
: One of the web sites claim that a tire will run cooler on nitrogen. If it
: did, that alone could explain some of the advantage to lower pressure rise.
: But what I'm fuzzy on, is why would nitrogen run cooler? And how much
: cooler?
:
:

Go back to the nitrogen is drier for your answer...

"Dan" wrote in message ...

: Not as fast as helium which has a smaller molecule. For a good time
: partially fill the tyre with water.
:
: Dan, U.S. Air Force, retired

And then let it freeze ;-)

Dan, not USAF, still working....

"Blueskies" wrote in message
...

"Maxwell" wrote in message
...
:
: "andrew m. boardman" wrote in message
: ...
: Kyle Boatright wrote:
: I'm not 100% sure what Clare means by "more temperature stable,
pressure
: wise.", but all gasses follow Boyle's law, which is Pressure x Volume
=
: Number of moles x Avogadro's number x Temperature... PV=NRT.
:
: The problem with a strict gas-law analysis is that a tire filled with
: compressed air has moisture hanging around in both vapor and liquid
form;
: the ratio varies with temperature, which makes the math all annoying
and
: nonlinear, and worse, variable between tires.
:
: On the other hand, this often gets translated to "nitrogen doesn't
expand
: when heated, unlike air" by authors who really ought to know better;
this
: is complete crap. The difference is *really* marginal, though cutting
: down on oxidation is much more relevant.
:
: One of the web sites claim that a tire will run cooler on nitrogen. If
it
: did, that alone could explain some of the advantage to lower pressure
rise.
: But what I'm fuzzy on, is why would nitrogen run cooler? And how much
: cooler?
:
:

Go back to the nitrogen is drier for your answer...


Where at, I didn't see anything on it.

Dan wrote:
Gig 601XL Builder wrote:
Scott wrote:
What about hydrogen? It's lighter than air and will boost lift at
the same time

Scott


Little bitty molecules will leak out faster.


Not as fast as helium which has a smaller molecule. For a good time
partially fill the tyre with water.

Dan, U.S. Air Force, retired

True but only because H runs in pairs.

Scott wrote:

So, all jokes aside, what is the reasoning of using Nitrogen? Something
to do with no oxidizing because of lack of O2??? I get many years out
of a set of baloney skins and the tread wears off before they rot out,
so it seems like it would just be added expense. Plus, I believe a tank
of Nitrogen would last 100 lifetimes if all you used it for was to fill
airplane tires.

Scott

The reason I use compressed nitrogen at the races is because it is the easiest
way to get compressed "air". Otherwise I would have to carry a compressor or an
air tank.

If you don't already have a compressor, it may be a good way to get a source of
compressed air for your hangar. A small bottle and regulator is very convenient
for filling tires and other uses.

CW

: But what I'm fuzzy on, is why would nitrogen run cooler? And how much
: cooler?
:
:

Go back to the nitrogen is drier for your answer...


Where at, I didn't see anything on it.


The documentation will probably be difficult to locate; but I'll make a
guess and wait for someone to correct me.

Nitrogen probably runs stightly warmer than compressed air that was not
dried. However, the water in the moist air *may* change state during
operation; which would lead to a greater pressure increase--that might lead
to the presumption that the temperature rise was greater.

We reason for saying that water *may* change state is that it might not be a
big deal for a C-150 used for training in Florida, where the tire
temperature range over the course of a day should be fairly narrow; but
could get nasty for a B-747.

Also, whether correctly or not, I would expect high pressure bottled gas to
be *very* dry; but I don't know whether gas from a small concentrator will
be significantly drier than dried compressed air. In any case, the gas from
the small concentrator will almost certainly be less pure.

Basically, I believe that this is serious business on almost any jet. And
at the other extreme, when I was flying a C-150 or a C152 is a student, I am
pretty sure that I was the only student who ever verified that tire
pressures met spec when they didn't quite pass a visual--and reinflated as
needed on a couple of occasions--but AFAIK they never had any problems, so
the tires on the little trainers were *very* forgiving. In between is
probably in between.

I hope this helps.

Peter

Blueskies wrote:
"Dan" wrote in message ...

: Not as fast as helium which has a smaller molecule. For a good time
: partially fill the tyre with water.
:
: Dan, U.S. Air Force, retired

And then let it freeze ;-)

Dan, not USAF, still working....


Works rather well for the kick off in a football game

Dan, U.S. Air Force, retired

On Wed, 11 Apr 2007 20:16:53 -0400, "Kyle Boatright"
wrote:

clare at snyder.on.ca wrote in message
.. .

And ordinary compressed air is already 80% nitrogen.
But the oxygen and ozone, along with a few other gasses does
accellerate the deterioration of the rubber, and the nitrogen stays in
better than the rest (co2 included) Also more temperature stable,
pressure-wize.

--
Posted via a free Usenet account from http://www.teranews.com

I'm not 100% sure what Clare means by "more temperature stable, pressure
wise.", but all gasses follow Boyle's law, which is Pressure x Volume =
Number of moles x Avogadro's number x Temperature... PV=NRT. Essentially,
for a given temperature increase, all gasses expand (or increase pressure,
given a fixed volume) at the same ratio.

KB

Kyle, those of us in hydraulics would really like to buy some of your
ideal gas ... our accumulators would work SO much better. GRIN

Argon does not conduct heat as well as nitrogen, likely insignificant
to any of our applications. Argon, I _think_ but cannot document, is
a monoatomic gas; nitrogen is diatomic. The heat/compression
equations are different; look at polytropic constants. Real gasses
are very complex in their behaviors.

Argon is more inert and more expensive. Over the years, I've searched
for definitive advantages for one over the other; all I have been able
to find is that even in non-price sensitive applications, like
military aircraft accumulators, where even the smallest advantage
would be taken, nitrogen is used.

I'd like to see some real research; there are some electro-hydraulic
applications that would gladly pay for the argon to improve system
stability, if it will.

George