Safety Stage bottle duration submerged?

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gearbow

Contributor
Messages
201
Reaction score
110
Location
Blairmore, Alberta, Canada
# of dives
1000 - 2499
Hi I am planning my first time doing exploration of a cave system. Nobody else dives this cave and I will be alone. I will be taking baby laying small leg at a time then coming back to survey that leg. As a extra precaution I would like to set a Safety Stage bottles along the way. Perhaps every 100 meters or at jump points. Not planning stages for extended reach just as added safety as I will be diving. I would never dive or push the boundary on my rule of thirds based on the knowledge I had a stage bottle near by. I would still plan the dives as if there was no stage bottles pressent.

My question is how long would you be able to leave a stage bottle with regulator submerged in clear clean water. I definitely would inspect bottles for signs of leaking by checking pressure gauge on the way by but how often would you check regulator?

I am planning on 4 aluminum 80s with cold water regs. Have not decided on what regs yet. Looking maybe on suggestions on that as well. The water is slightly warmer coming out of the cave it is possible that it has a bit of sulfur in it however I can not smell the sulfur. Not sure how I could test that but it does look like a bit of a hot spring. If it is Sulphur it could degrade the o rings. I might as well set them up for cold water extremes.
 
I left 2 safeties in a cave for about 4 years. They were retrieved recently and one of them was still full and functional, the other was emptied. Other projects have had safeties full/functional after even longer time periods.

A water heater anode on the tank makes a dramatic difference in cutting down on pitting of the metal.

It's good practice to check the pressure and reg function from time to time as the project goes on.
 
Take a water sample and get it tested. Some places will do it for nothing. Sears did it here as promotion to selling filtering systems. local ag department. expecially it the water has access to rivers ect. As corrosion goes see a shipyard or equivilant and get some bars removed form ships. there should be more than enough left of them for your use since they usually are used in salt water.
 
How long do you plan to leave them?


Sent from my iPhone using Tapatalk
 
At one system that we put prolonged safeties in, we went with steel 72s to reduce the issues.
 
As some of the examples above indicate you can leave a safety tank in a system for a long time.

But...let's be honest here. If you let the tank stay in the system so long that pitting, etc is a concern, you're really not relying on it for safety.

If you've left a tank in a system that happens to be empty, you've also done it wrong as you didn't bother to ever check it, not even to the extent that an empty AL 80 or steel 72 is now buoyant or tail light. Or you just never got around to removing it, or more importantly replacing it with a functional safety bottle.

You also have the regulator to consider and it's a more likely failure point than the actual tank, particularly if the gas leaks out of the first and second stage and the purge gets depressed, letting water into the system.

From time to time I see safety bottles with regs attached in shops that have obviously been in systems a long time and they are almost always in a prominent location where you can't help but see them. In that regard they become fashion statements attesting to some on-going or just completed exploration project. Fun too look at, but obviously not anything anyone ever took too seriously.

If you're exploring the home cave without support and while solo, you'll want to take your safety bottles a bit more seriously than that and ensure that you cycle them out on a regular basis for inspection and servicing. Six months is plenty long enough to leave one in the system, and if you've got acidic water, lots of silt or algae growth going on, etc, you'll want to do it more frequently than that. I wouldn't actually bother with water testing as at best it will just guide you initial estimate, and other factors will have equal or greater impact. The actual condition of the tank will be what you need to use as a guide once you're underway.

Even then if you've got several in the system, and they can last 6 months, you won't want to have to rotate them all out at once, so you'll probably want to pull a sixth of them every month or a third of them every couple months. Or just replace one on every several dives, hauling a fresh one in and dropping it along side the old one on the way in, then pulling the old one on the way out, never letting any of them get to the point they start to degrade.

Assuming you properly maintain them, you don't need to plant them much closer together than the distance you can swim on one of them, with some reserve to account for some gas loss in storage, and the slower exit speed in a silt out on exit.
 
As some of the examples above indicate you can leave a safety tank in a system for a long time.

But...let's be honest here. If you let the tank stay in the system so long that pitting, etc is a concern, you're really not relying on it for safety.

If you've left a tank in a system that happens to be empty, you've also done it wrong as you didn't bother to ever check it
, not even to the extent that an empty AL 80 or steel 72 is now buoyant or tail light. Or you just never got around to removing it, or more importantly replacing it with a functional safety bottle.

You also have the regulator to consider and it's a more likely failure point than the actual tank, particularly if the gas leaks out of the first and second stage and the purge gets depressed, letting water into the system.

From time to time I see safety bottles with regs attached in shops that have obviously been in systems a long time and they are almost always in a prominent location where you can't help but see them. In that regard they become fashion statements attesting to some on-going or just completed exploration project. Fun too look at, but obviously not anything anyone ever took too seriously.

If you're exploring the home cave without support and while solo, you'll want to take your safety bottles a bit more seriously than that and ensure that you cycle them out on a regular basis for inspection and servicing. Six months is plenty long enough to leave one in the system, and if you've got acidic water, lots of silt or algae growth going on, etc, you'll want to do it more frequently than that. I wouldn't actually bother with water testing as at best it will just guide you initial estimate, and other factors will have equal or greater impact. The actual condition of the tank will be what you need to use as a guide once you're underway.

Even then if you've got several in the system, and they can last 6 months, you won't want to have to rotate them all out at once, so you'll probably want to pull a sixth of them every month or a third of them every couple months. Or just replace one on every several dives, hauling a fresh one in and dropping it along side the old one on the way in, then pulling the old one on the way out, never letting any of them get to the point they start to degrade.

Assuming you properly maintain them, you don't need to plant them much closer together than the distance you can swim on one of them, with some reserve to account for some gas loss in storage, and the slower exit speed in a silt out on exit.

how do you figure people find out they're empty?
so much nonsense in this post
 
As some of the examples above indicate you can leave a safety tank in a system for a long time.But...let's be honest here. If you let the tank stay in the system so long that pitting, etc is a concern, you're really not relying on it for safety. If you've left a tank in a system that happens to be empty, you've also done it wrong as you didn't bother to ever check it, not even to the extent that an empty AL 80 or steel 72 is now buoyant or tail light. Or you just never got around to removing it, or more importantly replacing it with a functional safety bottle. You also have the regulator to consider and it's a more likely failure point than the actual tank, particularly if the gas leaks out of the first and second stage and the purge gets depressed, letting water into the system. From time to time I see safety bottles with regs attached in shops that have obviously been in systems a long time and they are almost always in a prominent location where you can't help but see them. In that regard they become fashion statements attesting to some on-going or just completed exploration project. Fun too look at, but obviously not anything anyone ever took too seriously. If you're exploring the home cave without support and while solo, you'll want to take your safety bottles a bit more seriously than that and ensure that you cycle them out on a regular basis for inspection and servicing. Six months is plenty long enough to leave one in the system, and if you've got acidic water, lots of silt or algae growth going on, etc, you'll want to do it more frequently than that. I wouldn't actually bother with water testing as at best it will just guide you initial estimate, and other factors will have equal or greater impact. The actual condition of the tank will be what you need to use as a guide once you're underway. Even then if you've got several in the system, and they can last 6 months, you won't want to have to rotate them all out at once, so you'll probably want to pull a sixth of them every month or a third of them every couple months. Or just replace one on every several dives, hauling a fresh one in and dropping it along side the old one on the way in, then pulling the old one on the way out, never letting any of them get to the point they start to degrade.Assuming you properly maintain them, you don't need to plant them much closer together than the distance you can swim on one of them, with some reserve to account for some gas loss in storage, and the slower exit speed in a silt out on exit.
Anyone with even a little experience in this knows you're making stuff up. Just stop.
 
Anyone with even a little experience in this knows you're making stuff up. Just stop.
Please accept my sincere apology AJ.

I obviously misstated the facts, as you obviously have larger balls and are much more willing to bet your life on a nasty looking safety bottle and regulator left in a system for 3 or 4 years.

You're also obviously comfortable with presenting that time frame to the OP for his purposes, while I incorrectly assumed the OP might want to apply brains to his risk mitigation plan rather than balls. That's obviously not how it should be done, as that's obviously not how you've done it in the past.

Once again, please accept my apology.
 
https://www.shearwater.com/products/peregrine/
http://cavediveflorida.com/Rum_House.htm

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