Air Fills - Age of Air

Please register or login

Welcome to ScubaBoard, the world's largest scuba diving community. Registration is not required to read the forums, but we encourage you to join. Joining has its benefits and enables you to participate in the discussions.

Benefits of registering include

  • Ability to post and comment on topics and discussions.
  • A Free photo gallery to share your dive photos with the world.
  • You can make this box go away

Joining is quick and easy. Log in or Register now!

Messages
83
Reaction score
0
Location
Plano, TX
# of dives
50 - 99
Is there a certain window of time were the air in your tank degrades and can become dangerous to breath? ... Say for example you have tank that you filled up 9 months ago but did not use but want to now? Im not in the situation but I was wondering if there is a window of time for air?
 
Nope, people leave stage bottles in caves for months or years. It's not an issue.
 
im with him i have seen deco bottles sit for a very long time. i had my double sit for over a year when i was in iraq and when i came back another few month.when i finaly got in the water the air didnt kill me lol
 
In aluminum cylinders, it is not a problem. In steel, it COULD POSSIBLY become a problem. When steel tanks rust inside, the rusting process uses oxygen. If it rusts enough, you could end up with not enough oxygen content to supporl life. It doesn't take much to support life at depth but it does take at least 16 % to support it at the surface. Of course, steel tanks don't usually rust unless you get water in them. Still, if I planned on using some old air in steel tanks, I would analyse it for O2 %.
 
Unless it was sitting there for several years, I'd use it.



Even the old stuff might still get you where you want to go!!!
 
Whitelightnin:
In aluminum cylinders, it is not a problem. In steel, it COULD POSSIBLY become a problem. When steel tanks rust inside, the rusting process uses oxygen. If it rusts enough, you could end up with not enough oxygen content to supporl life. It doesn't take much to support life at depth but it does take at least 16 % to support it at the surface. Of course, steel tanks don't usually rust unless you get water in them. Still, if I planned on using some old air in steel tanks, I would analyse it for O2 %.
If 5% of the O2 in a full tank was depleted there would be a LOT of rust. I'd think there would be so much rust the tank would never pass a hydro, let alone a vip.

Joe
 
Sideband:
If 5% of the O2 in a full tank was depleted there would be a LOT of rust. I'd think there would be so much rust the tank would never pass a hydro, let alone a vip.

Joe
Actually I think some chemical engineer on this board proved your point in an old post that I don't feel like searching for, but I agree with you. To consume enough oxygen to create a hypoxic mix the tank would be too rusty to hold pressure
 
wedivebc:
Actually I think some chemical engineer on this board proved your point in an old post that I don't feel like searching for, but I agree with you. To consume enough oxygen to create a hypoxic mix the tank would be too rusty to hold pressure

University of Rhode Island did such a test. The tanks involved held pressure.
 
nadwidny:
University of Rhode Island did such a test. The tanks involved held pressure.
But if the mathematical model proved it impossible then the test must have been wrong - oh wait, I'm thinking of economics...:D
 
https://www.shearwater.com/products/swift/

Back
Top Bottom