Steel Model E Cylinder Buoyancy

[DenbyS]

Does any one have any buoyancy specs for a model E cylinder? These are typically used for medical O2, 4.2" diameter, 25.75" long. Apparently some are repurposed as pony bottles. I'm curious about the buoyancy and suitability for that application. I picked one up for practically nothing considering it has a fresh hydro with + and star stampings and an oxygen clean viz sticker.

 

[akdeepdiver]

Just fyi, as far as the government is concerened the star stamp for the ten year hydro is not valid if the cylinder is taken underwater and will revert back to the normal 5 year hydrostatic requalification. This can be referenced in 49CFR180.209(b)(V).

 

[Wookie]

Does any one have any buoyancy specs for a model E cylinder? These are typically used for medical O2, 4.2" diameter, 25.75" long. Apparently some are repurposed as pony bottles. I'm curious about the buoyancy and suitability for that application. I picked one up for practically nothing considering it has a fresh hydro with + and star stampings and an oxygen clean viz sticker.

I'd be surprised if someone were actually using E cylinders as pony bottles. Their buoyancy would suck, and the neck threads don't fit scuba valves. E cylinders are cheap, but 40 cu ft ponies are almost as cheap and designed for what they are being used for.

How are these folks hooking a regulator to a 2 pin valve?

 

[DenbyS]

Just fyi, as far as the government is concerened the star stamp for the ten year hydro is not valid if the cylinder is taken underwater and will revert back to the normal 5 year hydrostatic requalification. This can be referenced in 49CFR180.209(b)(V).

I was guessing that might be the case. Thanks for the info.

---------- Post added October 5th, 2014 at 03:41 PM ----------

I'd be surprised if someone were actually using E cylinders as pony bottles. Their buoyancy would suck, and the neck threads don't fit scuba valves. E cylinders are cheap, but 40 cu ft ponies are almost as cheap and designed for what they are being used for.

How are these folks hooking a regulator to a 2 pin valve?

The cylinder I acquired has a J-valve on it. Would you expect it to be too negative in the water?

 

[Scared Silly]

The cylinder I acquired has a J-valve on it. Would you expect it to be too negative in the water?

Yes, like it will go down like a lead balloon. I'd check the valve to make sure its threads were modified and not the cylinder.

 

[DenbyS]

Well, I've had the opportunity to sling the e-cylinder on two wrecks. I was pleasantly surprised to find how quickly I forgot about it in the water. At ten pounds out of the water it was easy coming up the boat ladder as well.
Both dives were in the 130' range, and I deployed it for ascending and stops. Good gas capacity in a skinny package.

My only negative was the valve. A j-valve with the knob on top was easy to operate but the shape tangled a little with my inflator. All in all I'm very pleased with the $15 investment.