Nitrogen in tires

[frankdamp]

The oxygen in air can support an explosion in the tire if it gets hot enough to release gases from the rubber.

Based on research I did at Boeing, you should use nitrogen if your RV can do 150 mph for a couple of miles with a dragging brake and then retract the wheels into a box. Otherwise, don't waste the time and money trying to find a source of nitrogen when you want to add pressure.

[3665RE]

Originally Posted by frankdamp

The oxygen in air can support an explosion in the tire if it gets hot enough to release gases from the rubber.

Based on research I did at Boeing, you should use nitrogen if your RV can do 150 mph for a couple of miles with a dragging brake and then retract the wheels into a box. Otherwise, don't waste the time and money trying to find a source of nitrogen when you want to add pressure.

Follow frankdamp’s explanation. It is correct he just didn’t finish the explanation.

Aircraft use Nitrogen for the following reason.

When you have a dragging brake or panic stop from 150 MPH the wheel and brake assembly gets very hot. When this temperature reaches a predetermine point there is a relief plug commonly call a “blowout plug” in the wheel. When this plug blows out the last thing you want blowing on your red hot brake which is inside your very hot magnesium wheel is an Oxygen / nitrogen mixture. Pure nitrogen is inert and doesn’t burn or cause acieration of the burning process associate with flammable products like magnesium.

After mounting a new aircraft tire the tire and wheel assembly is evacuated of air using a venture arrangement on the end of an air hose. Then the tire is inflated with nitrogen. A second time the venture is used to evacuate the tire of nitrogen and what little bit of oxygen may be remaining after the first evacuation. Then the tire is inflated with nitrogen and stored for 24 hours in a temperature controlled environment and pressure checked. If there is any decline in pressure the assembly is returned to the tire repair room for further examination to determine where the leak is.

I had the G614 tires installed on our fifth wheel 3 years ago. They were inflated with plain old air and I haven’t needed to put air in them yet. I had a Goodyear commercial tire dealer check the tires last week and they are still at 95 psi. which is the recommended cold pressure for the weight being carried. After towing the trailer 100 miles I checked the tire pressures and they were at 105 psi. which is normal for an 85-degree day and 60 mph speeds.

3665RE

PS: An aircraft wheel and tire assembly has to be deflated to 30 psi before a commercial air carrier can carry it as cargo.

[Mr_D]

Originally Posted by TXiceman

Using air from a compressor with a drier on it will pretty much eliminate the water problem......

Ken

Exactly what I said in post #5.

[Ray,IN]

I picked up my truck from the Chevrolet dealership tonight and noticed a sign promoting Nitrogen filling for tires-at a reduced cost this week only. I asked the service writer how they got the normal air out of the tire before inflating it with Nitrogen. He never answered, just stood there with a blank look. I said I had filled mine with 78% Nitrogen, his look never changed.

[JohnBoyToo]

Originally Posted by Ray,IN

I picked up my truck from the Chevrolet dealership tonight and noticed a sign promoting Nitrogen filling for tires-at a reduced cost this week only. I asked the service writer how they got the normal air out of the tire before inflating it with Nitrogen. He never answered, just stood there with a blank look. I said I had filled mine with 78% Nitrogen, his look never changed.

You big meanie - Don't be confusing those poor minimum wage boys !
thread hijack alert since we've beat this dead horse over and over by now

last night my wife actually told me to close my mouth as my jaw dropped watching a pretty young thing try to figure out the change for a $12.21 pizza when I gave her $20.21 !!!!

took so long her mgr actually came over to help even though I told her how much change to give me

[frankdamp]

3665RE:

The one incident I remember most vividly from my work was a tire blow-out in flight on a 727. The tire exploded at about 18,000 feet, blew a hole about 18" across in the aft wheelwell bulkhead and blew the gear doors off the airplane. Luckily, after quite a lot of suitcases had fallen out, two USPS mailbags jammed in the hole and slowed down the rate at which the cabin was decompressing.

When the tire was examined, the two steel cords in the bead had failed in tesnion, which we figured would have needed an instantaneous pressure spike of about 12,000 psi. Burnt rubber on the inside of the tire showed there had actually been an explosion. We figured the tire had reached a temperature where gases normally trapped in the rubber had escaped and then, with the oxygen in the tire, had spontaneously combusted.

Hence the recommendation to use nitrogen.

[3665RE]

Originally Posted by frankdamp

3665RE:

The one incident I remember most vividly from my work was a tire blow-out in flight on a 727. The tire exploded at about 18,000 feet, blew a hole about 18" across in the aft wheelwell bulkhead and blew the gear doors off the airplane. Luckily, after quite a lot of suitcases had fallen out, two USPS mailbags jammed in the hole and slowed down the rate at which the cabin was decompressing.

When the tire was examined, the two steel cords in the bead had failed in tesnion, which we figured would have needed an instantaneous pressure spike of about 12,000 psi. Burnt rubber on the inside of the tire showed there had actually been an explosion. We figured the tire had reached a temperature where gases normally trapped in the rubber had escaped and then, with the oxygen in the tire, had spontaneously combusted.

Hence the recommendation to use nitrogen.

Hi

I find this interesting. The Bowing 727 always from the day it was first produced for civilian use required the “blowout plug” and Nitrogen. The first Boeing aircraft to operate with “blowout plug” and nitrogen was the B-29. Douglas started using them in the DC-4. Northrop in the YB-49.

If your Bowing 727 had air in the tires it was contrary to the maintenance procedures in place at the time. It is agreed that air in the tires can cause fire and that in this event the “blowout plug” wouldn’t have the capacity to prevent an explosion.

While the original reason for the Nitrogen may well have been the fire potential inside the tire today the training concentrates on the carbon base brake and the Magnesium wheel as the reason for Nitrogen in the tires. My last recurrent training was last year on the G-III/G-IV and G-V. The year before that was the Bombardier 600 thru Global. Then there is the training session I attended at Avail’s tire shop in Atlanta in March again they referenced only the carbon brake and Magnesium wheel issue. I also did pilot training in the DC-9 simulator. The procedure for doing touch and goes was to leave the gear down for cooling purposes so you didn’t blow the “blowout plugs”. That was back in the 70’s. I never got to fly the aircraft and did very little maintenance on the one I was supposed to manage.

The last 727 I had anything to do with was being scraped at Opa-Locka Airport in Florida. They only wanted to recover the brake assembly’s and the blowout plugs the wheel went to the scrap yard. I never got to work on the 727 or fly it but did get involved for a short period of time scraping them.

I have years experience both maintenance and pilot with the DC-4, DC4/6 (only 6 built for Braniff) and the DC-6 A&B. all had blowout plugs and Nitrogen in the tires.

At any rate the Nitrogen in trailer tires is of no practical advantage.

3665RE

[JohnBoyToo]

Dang - and I thought I was on an rv site - not a nasa space shuttle site

carry on

[3665RE]

Originally Posted by JohnBoyToo

Dang - and I thought I was on an rv site - not a nasa space shuttle site

carry on

Like I said:

At any rate the Nitrogen in trailer tires is of no practical advantage.

But you can spend your money any way you like. LOL


3665RE

[XCamper]

Everyone!!!
I never expected to get so much response to a question about inflated tires. Thank you to all. I am sure I'll have more questions.....and I hope one day to have some knowledge to pass along to someone else.