storing tanks for winter

[mbalmr]

Thanks, I plan on doing some ice diving in the future. Not quite there yet equipment wise.

 

[halocline]

Don't worry about the loss of O2, it's an old dive shop tale. Those tend to be worse than old wives' tales. If your tanks are steel, just make sure that you get nice dry fills, or your tanks will get ruined. That's in general, not just for storage. If they're AL tanks there's even less to worry about, as they won't rust. Moisture is not good for them either, but it's not as bad as wet air in a steel tank.

There is a bit of a rule of thumb that you store tanks either filled or with only a small of air, maybe a few hundred PSI. The idea is that if there's a fire in the house and the tanks get hot, they are less likely to explode if they're near empty, or full enough to set off the burst disc before they get so hot that the metal fails. I don't know how much truth there is to that, but typically I end up storing tanks with just a few hundred PSI anyways. I certainly wouldn't empty one just to store it with low pressure.

As an alternative to storing them, you could load them up in your car, quit your job, and drive them down to FL to dive all winter.

 

[GrumpyOldGuy]

Well I never took chemistry. Like I said its probably not much of a concern but is a $5 air fill worth it? To me no but then again I dive year round.

It's not a question of money, we are all divers and spend it like drunk sailors on leave.

Last time I played with the numbers, you would need to have 1.3 pounds of rust to drop the oxygen content from 21 to 16%. With a typical annual VIP, you should only have flash rust and a few pits even with wet fills. Can it happen, probably if you store a full STEEL cylinder with standing water for years (no hydro / vip).

 

[Tracy]

Store them at my house in Livonia. I will dive with them all winter and keep them fresh for you.

Sent from my GT-P5113 using Tapatalk 2

 

[Doc Harry]

Since you asked......

http://www.scubaboard.com/forums/ta...-cylinder-long-term-storage-fact-fiction.html

Don't worry about the loss of O2, it's an old dive shop tale.

Yeah, NOAA frequently disseminates "old dive shop tales." So do some universities.

According to NOAA's "shop tales," there is one documented scuba death that resulted from somone who dove with a rusty steel cylinder. The formation of rust consumed almost all of the oxygen in the cylinder. Post-mortem analysis showed that there was only 2%-3% oxygen in the cylinder. The amount of rust found in the cylinder mathematically correlated to the drop in oxygen. [Schench, Hilbert V., and McAniff, John J. United States Underwater Fatality Statistics-1974. NOAA Report URI-SSR-75-10]

The University of Rhode Island did some scuba cylinder corrosion studies. They found instances where rust formation reduced the oxygen to only 15% in some cylinders.
http://inrhode.uri.edu/search/?sear...Search&searchlimits=&searchorigarg=tcorrosion

Read the above thread about long-term cylinder storage for the original articles and full details. It's heavy reading, but jump to posts #4 and #5 if you want to get to the meat of the rust/O2 issue.

 

[NAM001]

bleed to less than 100 and store for the winter. the ppo2 that riusts is drastically reduced.

 

[Teller]

Since you asked......

http://www.scubaboard.com/forums/ta...-cylinder-long-term-storage-fact-fiction.html

Don't worry about the loss of O2, it's an old dive shop tale.

Yeah, NOAA frequently disseminates "old dive shop tales." So do some universities.

According to NOAA's "shop tales," there is one documented scuba death that resulted from somone who dove with a rusty steel cylinder. The formation of rust consumed almost all of the oxygen in the cylinder. Post-mortem analysis showed that there was only 2%-3% oxygen in the cylinder. The amount of rust found in the cylinder mathematically correlated to the drop in oxygen. [Schench, Hilbert V., and McAniff, John J. United States Underwater Fatality Statistics-1974. NOAA Report URI-SSR-75-10]

The University of Rhode Island did some scuba cylinder corrosion studies. They found instances where rust formation reduced the oxygen to only 15% in some cylinders.
InRhode

Read the above thread about long-term cylinder storage for the original articles and full details. It's heavy reading, but jump to posts #4 and #5 if you want to get to the meat of the rust/O2 issue.

Im not sure how its considered a old dive shop tale if there has been a documented case of it. Thank you for the link. I read a different but similar case a while back.