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View Full Version : Totally hypathetical (im not going to do this)



trekkindave
08-14-2008, 15:44
I was doing a rig check today at work, and realized that the oxygen cylinders we use on the ambulance are made by catalina....

here is my dumb question for you...


Do you think it is possible to remove the neck valve on a medical oxygen tank and replace it with a scuba neck valve and use it as a small pony bottle?

I know the medical tanks are rated to 2000psi..

what do you all think?

MSilvia
08-14-2008, 16:20
I'm not sure about the threads matching up, but with an adaptor it should work. Not ideal, but possible.

in_cavediver
08-14-2008, 16:51
It will work with the old straight thread post valves (usually j style) and very hard to find. Another problem is that the buoyancy characteristics suck. Very positive. Think how light that E bottle is compared to your average scuba tank.

I do keep one (E) with the med o2 reg for surface o2 use though. Looking for a smaller one for a jump bag I'm putting together as well but that's another story.

navyhmc
08-16-2008, 20:06
The threads on a D-cylinder are different than the ones on a tank.

trekkindave
08-16-2008, 20:08
Thank you. Saves me some trouble of buying a valve to try it..

Duckydiver
08-16-2008, 20:25
you could just use a standard o2 reg with the 50 psi dss port and try to get a 2nd stage reg to work off that. kinda those old positive pressure mask thingys

in_cavediver
08-16-2008, 20:41
The threads on a D-cylinder are different than the ones on a tank.

Way back when (late 60's early 70's), there was a 1/2" straight thread valve option on tanks. Basically the same design as the 3/4" thread we use in scuba today but of a smaller diameter. Most of the old 1/2" tanks were taper thread but not all. If you found the straight thread valve, you could use it with the O2 bottle today.

Still, not worth it for other reasons.

WD8CDH
08-18-2008, 15:52
The aluminum D and E medical tanks are .750-16 UNF o-ring seal. I have never seen a SCUBA valve that came with those threads. I have rethreadsd 3/4-14 NPS Scuba valves to fit but it's more expensive than buying a new SCUBA tank.

h2odragon1
08-19-2008, 09:05
Why not just get a 13 cubic ft tank and have it o2 cleaned?
Or are you planning a little midnight aquisition?

trekkindave
08-19-2008, 11:37
midnight, noon, 1015am.... there are plenty available.. but your right.. just getting a 13 cf pony would probably be better.. especially since it would come with the proper valve anyway.

in_cavediver
08-19-2008, 11:46
The aluminum D and E medical tanks are .750-16 UNF o-ring seal. I have never seen a SCUBA valve that came with those threads. I have rethreadsd 3/4-14 NPS Scuba valves to fit but it's more expensive than buying a new SCUBA tank.

You're absolutely right. I was confused with another AL O2 tank that was old avaiation tanks.

Luis H
09-29-2008, 19:40
The old O2 tanks used the same 1/2 NPT tapered pipe thread as old Scuba tanks. Some of the first pony bottles were just converted O2 bottles.

I have seen pictures of wreck divers in NJ back in the mid 60s with double steel 72, double hose regulator, and a pony bottle nested on the back of the double. The pony bottle was a converted O2 tank.

waytooslow
09-29-2008, 19:50
no jab dave, but

hypothetical definition |Dictionary.com (http://dictionary.reference.com/browse/hypothetical)

good read though