Depth question

[wetman]

What effect does depth have on tanks? Do deeper dives affect tanks in different ways over time than shallow ones? Or does it not matter at all.

steve

 

[large_diver]

Steve,

This is an "off the top of my head" reply...

....I have to believe that the effect of depth on tanks is negligible. The pressures exerted by diving to rec depths (<130 ft) are not nearly as stressful as the pressure they are being submitted to via gas fills.

 

[Green_Manelishi]

you'ld have to be WAY deep for the surrounding water pressure
to crush a full tank. And if the tank were NOT full you'ld still
need to be way deep.

as I do the math (correct me if i am wrong):

2640 psi (in the tank) / 14.7 psi (atmosphere) = 179.59183
("atmospheres in the tank")

179.59 * 33 (feet per atmosphere) = 5926 feet ...

like I said ... way deep

 

[wetman]

I'll have to watch the cobra carefully as i approach that depth then

steve

 

[joewr]

Originally posted by wetman
I'll have to watch the cobra carefully as i approach that depth then

steve

Wetman,

You are out of luck: the Cobra only goes to 5925 ft. However, you can buy the special deep water diaphragm attachment--which can be converted to a Captain Midnight Decoder--for an extra $100.00. That will allow you to go to 5930 ft and still be able to use your computer...

Joewr...wondering if the Highway Dept. dug the Marianna Trench...that would explain why it was never filled in...

 

[jobowker]

About the only effect that depth has on your tank at recreational depths is that at depth you suck through air a lot faster (you're breathing air at a higher pressure). Also, going back to GM's example, 2640 psi would occur around 5296 feet, but even that wouldn't crush the tank. When your tank is getting a VIP, they empty all of the air out. If you were to close the valve at this point, the pressure on the outside of the tank is equal to the pressure inside. This doesn't make the tank want to implode. The pressure outside would have to be several times greater than the pressure inside the tank, so it would be some multiple of 5296.

 

[neil]

Let's see:
Assuming an RMV of 1 cu. ft./min, at 5296 feet, an aluminum 80 would last...30 seconds.

Neil

 

[dc4bs]

Originally posted by neil
Let's see:
Assuming an RMV of 1 cu. ft./min, at 5296 feet, an aluminum 80 would last...30 seconds.

Neil

AND to avoid O2 CNS problems it would need to have about 0.78% O2 in the mix to keep PO2 below 1.4 (as it would probably be classed as a stressful dive, NO?)...

Wow! Have to worry about narking too. What 2% N2 OK? PN2 of about 3.6 shouldn't be too bad...

"Hi, I'd like these 20 AL80 tanks filled with .78% O2 2% or less N2 and the rest helium please. I'm planning a 10 minute DEEP dive tomorrow... Oh, and the Semi trailer full of stage bottles outside will need fills as well. My assistant has a list of mixes. Is that a problem?" =-)

You would still have a squeeky voice from all that helium a week later...

 

[Arduous]

Gee my dive computer go’s to all dashes after 350 feet and I paid good money for the darn thing.

Wow did this thread go astray or what ??????

 

[wetman]

very funny