This may be a silly question...

Does anyone use nitrogen instead of normal compressed air?

Nitrogen is very inexpensive (refills are easy at any compressed gas store) and a small tank (about the same size as a fire extinguisher) can hold 2000psi,regulated down to whatever you want (say 100psi)
Plus since it is 99.9% dry, there is little worry about humidity in your air system...ever

I ran a small N2 bottle for many years when my son was karting and was thinking the same system would work well for turbine air systems.

Or am I over thinking this ?

I'm not using nitrogen but I am using highly compressed air from a paintball tank. I'm very happy with it.

The paintball tank will hold 3000 psi, 48 Cu In and will be more than enough for a couple days flying. The built in regulators bring it down to 850 psi. Then you need a secondary regulator to bring it down to 100 psi or so.

The secondary regulator I'm using is a little pricey, specially made for airsoft guns. But I did see a hack on Youtube where you can modify the primary regulators on the paintball regulator changing/removing the bellville washers to get it down to 100 psi.

You can easily fill the Paintball tanks with a Scuba tank in a matter of seconds.

Yes it does seem like overthinking and over kill. But the air that comes out of the tank is bone dry and cool. No batteries. It fills the on-board tank in about 5 seconds, very quiet.

I think Nitrogen would work great also. I see no downside.

To Fill a Scuba tank it costs $5 and lasts a long time. If you take the paintball tank to a shop you bought it at they will often fill it for free just to keep you coming back into the store.

Happy Flying,

SteveK

I know guy's using it... They swear by it. No moisture. I could see the advantage with electronic valves.. I do not though... I just tease them for making it just that much more .... whatever.. LOL

Danno

Isn't nitrogen used in a/c tires so they don't burst at high alt? That's what I always thought anyways.

Cant do any harm, as compressed air is already 80% nitrogen..

Isn't a paintball store gonna refill that tank with CO2 if you take it to them?

The lack of moisture content minimizes pressure rise due to the temperature rise (think landing)
the lack of moisture is also "electronics friendly' and helps with damage due to humidity impingement.

You can use a single regulator like this one
http://www.amazon.com/gp/product/B00...CQATBA8CBRPYDA

No, it a good idea in fact. Nitrogen is practically inert and does not degrade seals etc. Oxygen in regular air is of course very reactive. Coupled with moisture it gets worse. Nitrogen is also a pretty large molecule and so does not find its way so easily through materials. Helium is also very inert also but its so small that it easily finds its way out of a pressure vessel.

oxygen free nitrogen is used in mig and tig welding this might be even better as no moisture problems from oxygen

Actually, it's just the opposite. At high altitudes the air pressure drops in the tires to the point that some have actually had the bead unseat and fail on landing. Nitrogen doesn't react to cold to anywhere close to that extreme so the tires never lose enough pressure to have them fail in the same way.

Over thinking? All I know is that my Eurosport is coming up on 4 years old, over 350 flights, uses a Robart retract valve and filler and ProLink gear. I fill every flight with a Inexpensive air pump. My gear has never failed to retract or extend and will hold air pressure for weeks on end. Moisture in the lines? Yes I see that from time to time and it doesn't seem to affect my operations.
My 2 cents

Well that's a new one !
Never heard that before!!
In fact nitrogen is used in A/C tyres so that in the event of a wheel brake fire and tyre burst, or the fusible plug releasing the pressure, there is no oxygen in the compressed tyre gas to feed the brake fire.
The B 737 has exposed main wheel tyres , no doors, never had a tyre failure on landing or read of a Boeing warning of the possibility due to that cause.

In fact, the use of dry nitrogen in model air systems would be good, ( for reasons explained by turbotronic) we pump too much moisture into our systems using ambient air and the moisture DOES lead to corrosion, and as a result I am a strong advocate of a water trap on our air compressors.

Nitrogen is also used to prevent water from pooling inside the tire, then freezing at altitude, and due to there not being enough time from top of descent to landing for the ice to melt, the ice then can throw the tire out of balance on landing creating a bad vibration, or loss of the tire, and possibly aircraft control.

Never heard of that either ,seems in 20 years as a Boeing (training) captain I must have been living in enormous ignorance.

I.ll ask the real experts on pprune !

Yes Dan but they can use any dry air to prevent that. The primary reason are those listed by David.

Friend of mine is using. Seems happy with result so far...

Hey Chris! Hope all is well this New Year! I was just giving another reason that I was taught as a Boeing, and Corporate Jet Capt. They are all good reasons. I think it is more critical on Corporate Jet nose tires, since they have a small capacity volume, are at high pressures of around 110psi, and have a higher RPM then the larger tires. I have experienced even just having uneven tire pressures on the nose tires can create handling problems.
But, back to the OP's question, No, I just use a cheap yellow pump from Harbor Freight.

Every aircraft I've ever flown has used nothing but nitrogen in tires, blowdown bottles, canopy jettison bottles, etc. When purging fuel tanks etc. prior maintenance, nitrogen is used there as well. Lastly, I know nitrogen is used to purge petrochemical vessels and lines before welding. The only risk is that it displaces oxygen (precisely why it's used in the latter), and in extreme situations could potentially cause unconsciousness if enough leaks in a confined space.

I used my kids paintball nitrogen bottles for years on my model jets, just bought a paintball regulator and a button switch.. i had to be very careful not to over fill pressure wise.. it worked well. One drop of oil in each valve in the spring before the year.. I sometimes has some self induced leaks and had to keep a spare tank..

Finally I bought a good air pump, bought one of todd's little air dryer filters and never looked back. still one drop of oil per year in my valves.. I use air tool oil. so will it work..yes very well, is it necessary? not really..

The best application of nitrogen (in liquid form) is to make frozen yogurt....
Of course its also used in high performance car tires for reasons other than that mentioned here for aircraft. Temp/pressure stability in car tires which holds true for aircraft as well to a degree. Also helps with corrosion of them mags. And some mag castings can be porous ( but only if made it Italy ..). Nitrogen helps for that too, being a large molecule.