Nitrogen fill for tires?

[LETMGROW]

Originally Posted by brobox

When you are a broke GI, guaranteed we did not have Yeti coolers. Flight line nitrogen carts worked just fine and it was "free".

When I was a broke GI we used a CO2 fire extinguisher. You had to be careful your hand didn't freeze to the cans.

[Old-Biscuit]

Originally Posted by brobox

They were also fantastic for getting a quick chill on a case of beer at 4pm on Friday. And that is a fact not found on this post.

Originally Posted by LETMGROW

Thank you! That might be the most useful information in this whole thread.

Oops, cancel that. I called my local welding supply company. I guess I'll stick with frozen H2O cubes and my YETI cooler!

Originally Posted by brobox

When you are a broke GI, guaranteed we did not have Yeti coolers. Flight line nitrogen carts worked just fine and it was "free".

WE just place the large cone from fire extinguisher over 6 pack and gave it couple blasts.........Ice Cold Beer!

[jadatis]

Originally Posted by Tony65

Hi! When you have some time, try to put aside the conjectures and various fantasies and read this article that attaching.

The title is: TIRE NITROGEN FILLING SYSTEM. A final report to: Industrial Technologies Sector of Ingersoll Rand Corporation by:
Nader Jalili, Ph.D.
Prakash Venkataraman, Graduate Student
Department of Mechanical Engineering
Clemson University, Clemson, SC 29634-0921

What's the point of chatting without the appropriate knowledge?

There are people who have already studied these things from a scientific point of view, clarifying all aspects. So how about reading and learning from those who know more than us?

Read more, talk less and will learn much more.

Anyway, I've always used nitrogen, even on motorhomes, and I've never regretted it.

Unfortunately it is difficult to find it, this is true.

I downloaded the pdf, but see a exageration.
In 400 hours in fig 1 red and black, wich must be Nitrogen filled drops from 49.52 psi to 49.35 psi so to 99.65%, I calculated in 4000h to 96.66%
The blue and green line must be dry air filling goes to 49.16 psi is 99.27%, I calculated in 4000h to 92.96%. That 4000h I used to make the differences larger and more realistic, about 160 days.

Then this gives with my calculations N2 1.07 times the deflection so heatproduction, so energy loss, wich to my opinion can be compared to rolling resistence.
Dry air comes to 1.15 times rolling resistence.
To my logical thinking the dry air filling then 1.15/1.07=1.07 times more rolling resistance.
What they give in fig 2 is 3.75 times as much rolling resistance, a rabit kind of multiplication.

So then they can have 100 times Phd, but logical thinking learns that this can never be right.

I googled Ingersoll Rand Corporation, and it sels machines to make Nitrogen for filling tires,

[brobox]

Originally Posted by Old-Biscuit

WE just place the large cone from fire extinguisher over 6 pack and gave it couple blasts.........Ice Cold Beer!

Yep, C02 worked well too. What ever was closest. There's a guy that has experience as well. no off the wall theories, just cold beer.

[joelsplace]

Did you forget I'm driving the tire loaded when the ambient temperature reaches 90? 110psi + 14% is 125.4psi. My tires go over 135psi with far less ambient temp change.

[Ludo]

Originally Posted by joelsplace

Did you forget I'm driving the tire loaded when the ambient temperature reaches 90? 110psi + 14% is 125.4psi. My tires go over 135psi with far less ambient temp change.

Tires "work" and get hot, has nothing to do with ambient temperature.

[joelsplace]

That is my point exactly. Also running on asphalt in the summer adds a lot of heat to the tire.
So when the tire says 110psi max at ambient temp it really means 90-130psi. Just be sure it has air in it. It doesn't really matter all that much.

[brobox]

Originally Posted by LETMGROW

When I was a broke GI we used a CO2 fire extinguisher. You had to be careful your hand didn't freeze to the cans.

I had forgotten about that. At least we learned a lot about this scientific posting in real life. I still can't believe there is 108 post about air, with only 3 of us giving true facts. Along with CO2 it will get your beer cold instantly.
A true fact, I have not used nitrogen in a class A in over 30 years. I have never had a tire fail before aging out.

[LETMGROW]

Originally Posted by brobox

I had forgotten about that. At least we learned a lot about this scientific posting in real life. I still can't believe there is 108 post about air, with only 3 of us giving true facts. Along with CO2 it will get your beer cold instantly.
A true fact, I have not used nitrogen in a class A in over 30 years. I have never had a tire fail before aging out.

At least we know those discussing cooling beer know what they are talking about. The others? Questionable.

[brobox]

Originally Posted by LETMGROW

At least we know those discussing cooling beer know what they are talking about. The others? Questionable.

I thought the same exacting thing. For a fact, we do have more experience. I could go into why the USAF uses nitrogen in tires, but it does no good as a MH will never reach the freezing altitude 30,000 feet. I am good with an air doubler putting in 100% dry air from the dryer that is part of the Cummins engine.

[TXiceman]

The nitrogen use is among the long-time discussed RV issues that will never be solved.

If you manage to run your RV at speed approaching a 150 to 200 MPH or at extreme altitudes with freezing temperatures, you really do not need nitrogen.

Of course, you can use nitrogen if it makes you feel better and don't mind the hit on the wallet.

Ken

[Tireman9]

Originally Posted by RandyHart

Because of the size of the molecules nitrogen does not fluctuate as much as normal air or leak as easily and costco has free nitrogen at most locations! Just saying!

O2 does have a greater molecular weight (32) than N2 (28), but O2 is actually smaller in size. Thus, O2 fits through the relatively tight passage ways between polymer chains in the rubber more easily than does N2. The difference is size between O2 and N2 is very small, only about 0.3 times 10 to the -10th meters (0.00000000003 meters)


I do not find any reference to Molecule size change with temperature. Can you cite your sources?


My Source is
https://www.getnitrogen.org/pdf/graham.pdf

[Tireman9]

Originally Posted by joelsplace

That is my point exactly. Also running on asphalt in the summer adds a lot of heat to the tire.
So when the tire says 110psi max at ambient temp it really means 90-130psi. Just be sure it has air in it. It doesn't really matter all that much.

Sorry but that is not what "Max" pressure means on a tire sidewall. That pressure is the pressure needed to support the stated Max Load. There in no increase in load capacity even if you increase above the stated "Max" pressure.

[Tireman9]

Originally Posted by Big-Foot

I worked on race teams for many years and I can say with all honesty that when our tires were mounted, they were filled with air from a compressor which had a moisture trap on it. When pressures were adjusted at the track, we used the same Nitrogen that our air impact guns ran on. Why Nitrogen? Because we had two bottles charged up to 3500 PSI on the pit carts since we couldn’t drag compressors around. Nitrogen was inexpensive, didnt support combustion (important in hostile environments like the pits and also transporting)…
We saw between 8 and 10 PSI gain from cold pressure to racing pressures which coincidentally were reached when the tire temps reached their optimum grip from 180° to 200°. Race rubber compounds are formulated to get their best grip at these temps.

Now I think what everyone may have missed here is the delta between cold and hot being 30PSI and that you were having alarms set off from overpressure..
My thought is that if you are seeing more than 20 PSI growth, that you may well be overloading those tires and they’re overheating…

My various motorhomes and various trailers never seem to gain more than 15 PSI and I’m pretty well anal about checking pressures before heading out on a trip. Also using TPMS Sensors that register pressure and temps.

Food for thought….

TPMS High Pressure Alarm is set too low. I have found that a +25% above the Ambient "Set" pressure is good. This assumes of course that:


1. The RV was weighed and you know the weight on the heaviest loaded tire on each axle.


2. You consulted industry tables to learn the MINIMUM set pressure


3. You added a +10% margin on that minimum pressure (not to exceed the wheel rating) to avoid day to day normal pressure change due to normal Ambient change.



4. Your had gauge used when you set the pressure and the gauge has been checked against known accurate (+/- 2% or less) gauge


5 you inflated all tires on an axle to what the heavy loaded tire needs.



5. You are not traveling faster on ST type tire or faster than 75 on LT or "Truck/Bus radials.




Or you can depend on the Interweb for your knowledge as we all know that everything posted on the Interweb is 1005 accurate and true.