SCBA for Scuba?

[DeepDiver36]

I think I know the answer already but I thought I would pick some minds on the forum.

I have come into possession of a brand new, SCBA tank. It is rated at 2200 and change and is the perfect size for the wife that has a great SAC rate and would last as long, if not longer, then me on an AL80.

Has anyone ever seen a SCBA tank used for diving and is it even possible?

I know the valve hole is smaller then an standard K valve so if they have been used, is there a valve for using it as a diving tank.

Thanks in advance.

 

[captain]

No problem using the tank if you can get a proper scuba valve but I don't think you will be able to find one to fit the tank.

 

[mike_s]

I think I know the answer already but I thought I would pick some minds on the forum.

I have come into possession of a brand new, SCBA tank. It is rated at 2200 and change and is the perfect size for the wife that has a great SAC rate and would last as long, if not longer, then me on an AL80.

Has anyone ever seen a SCBA tank used for diving and is it even possible?

I know the valve hole is smaller then an standard K valve so if they have been used, is there a valve for using it as a diving tank.

Thanks in advance.

what's the tank made of?

if it's aluminum, like captain said, you can get a valve and do it. but since they are smaller and lower pressure for "surface consumption" and air consumption goes up as you increase depth, they just aren't as popular.

if it's a fiber wrapped tank, you'll have to wear so much lead to make it negative, that you might not want to mess with it. (in my opinion)

 

[WD8CDH]

Some SCBA tanks have 7/8"-14 UNF threads and you can get 300 bar DIN SCUBA valves in that thread but not yoke valves.

That tank is probably very buoyant and would require a heavy weight belt. Your wife would probably be better suited with an AL63 which is the same diameter as your AL80 but about 4" shorter. Other choices might be an AL50 or AL53. You can see the specs here:
SCUBA Cylinders

There are also smaller steel tanks. A used LP71 or a newer HP71 or something similar would be reasonable choices.

 

[DeepDiver36]

It is an AL with a very small thread hole on top, eye balling it maybe 1/2". I could not find a valve online that looked like it would work. Other then then that, it feels and weighs like I think an AL63 would. In the end, it seems like more of a PITA to fit this then to just buy one made for SCUBA.

Thanks for the thoughts and if anyone does know of a valve that would work, please let me know. I can always use a backup tank.

 

[tc]

I think those SCBA's are 1/2".

If you can find an old 1/2" valve still around you might be able to use it, don't think anyone is still making those.

 

[Graeme Tolton]

How heavy is it? I am wondering about the buoyancy characteristics of it. Also, by the time you buy a new valve for it, you are probably better off just buying a good used al63.

 

[WD8CDH]

It is an AL with a very small thread hole on top, eye balling it maybe 1/2". I could not find a valve online that looked like it would work. Other then then that, it feels and weighs like I think an AL63 would. In the end, it seems like more of a PITA to fit this then to just buy one made for SCUBA.

Thanks for the thoughts and if anyone does know of a valve that would work, please let me know. I can always use a backup tank.

What is the brand and original hydro date? I may be able to look up the neck threads.

Aluminum SCBA tanks were usually 7/8"-14 UNF, 3/4"-16 UNF and very rarely 5/8"-18 UNF. 7/8"-14 is the only aluminum SCBA thread that SCUBA valves were made for.

If that tank is made by Luxfer, is 6.75" diameter and about 21 inches long. it holds about 45CF and is much more buoyant than an AL63. It also probably has 3/4"-16 UNF threads.