Does gas go bad / expire / go stale in a tank?

[Rick Inman]

I wouldn't breath off a tank I didn't know. Who knows, maybe someone filled one with aragon!! Not likely, I'm sure, but why chance it.

 

[GotAir]

To Funny :11ztongue Taste Test results
I went into my computer/scuba room after brushing my teeth. whipped out my favorite reg hooked it up to one of the tanks ( I know the diver so i knew there was only air put in there) opened the valve and slowly took some hits of air off the reg, swished it around like good whiskey Hmmm I said. took a few more hits of air no funny taste so I quickly put my reg on a tank that had been filled a few weeks ago. hit on that for awhile and no differance as far as taste Hmmmm.

Bottom Line!

Both tanks had less than 800 psi in them so there off to the hydro place :dazzler1:


Mike

 

[miketsp]

Isn't exposure to air for prolonged periods of time the reason why stuff goes stale?

Yep, the process is called oxidation.
Causes changes of food flavor into stale, tasteless or fishy.
May change the nutritional value of lipids into toxic ketones and aldehydes.
May kill natural colouring.

Hope there's no food in my cylinder.

 

[Scubakevdm]

Yep, the process is called oxidation.
Causes changes of food flavor into stale, tasteless or fishy.
May change the nutritional value of lipids into toxic ketones and aldehydes.
May kill natural colouring.

Hope there's no food in my cylinder.

Here's what I'm saying though, how does air go stale?

 

[miketsp]

Here's what I'm saying though, how does air go stale?

I understand that either O2 is depleted in the gas mixture due to oxidation of the cylinder itself or other impurities or the O2 has reacted with some impurity present to form a volatile compound, ie contamination present as gas or vapour.

 

[Kim]

I think this is more of a problem in a steel tank - the oxygen and steel will together form rust - both using up the oxygen and damaging the tank. I don't think the same applies to Aluminium.

 

[Pierre Siquet]

12 years old air must be less poluted than nowaday's

 

[miketsp]

12 years old air must be less poluted than nowaday's

Not necessarily, quite a few industrial cities were unbreathable 12 years ago and modern cleanup programmes have improved them.

 

[wedivebc]

12 years old air must be less poluted than nowaday's

I think in this country 12 yo air is more polluted (less cigarette smokers).

I read a thread like this a while ago on SB where someone figured you would have to oxidize several pounds of steel to remove the O2 from the air in a tank. I will try to find it.

cheers,

 

[miketsp]

I think in this country 12 yo air is more polluted (less cigarette smokers).

I read a thread like this a while ago on SB where someone figured you would have to oxidize several pounds of steel to remove the O2 from the air in a tank. I will try to find it.

cheers,

I did a similar calculation on a previous post. Just punch in the new figures:
http://www.scubaboard.com/showpost.php?p=622009&postcount=6