Nah, it doesn't need to be stored unpressurized, it's just usually cheaper/easier since liquid nitrogen is cheap and will keep for a week or more in a dewar before evaporating completely away. It can also be stored pressurized in liquid form.

My lab in college actually had plumbing- hot water, cold water, deionized water and liquid nitrogen. If we needed liquid nitrogen, we'd just carry over a dewar (usually just plain ole styrofoam), open up the spigot and fill 'er up. Man, that was nice. Hmmm... now that I think about it, don't think it would work in practice to use the same bottle both for nitrogen gas for tires and liquid nitrogen for playing. I suppose in the end, I'd be better off just renting a dewar for a few days to play with..

 

Or just go drink some dewars and forget about it.

 

The new super insulated dewars will easily last over a month.

 

I have liquid @ work...should a smuggle out a teaspoon and get the tires to drink the cool-aid

 

That is a little rediculous. Running our entire shop off of nitrogen costs $40-60 per year, if we only did tires it would be about half that or less

 

LOL, Not this one again.

Nitrogen fill,

Did you also know that if you take your hard earned cash and throw it up in the air chances are the wind will blow it away.

 

Ha, that is true. There are specific advantages to nitrogen filled tires, but none worth paying for on a street car.