DIY O2 kit

[willo]

I'm planning on getting O2 certified for scuba injuries.
The logistics of scuba injuries dictate it, I believe.

DAN kits are really nice, but also EXPENSIVE.
Any suggestions on parts for my kit?

I'm looking for advice on regulators, demand valves, masks and tank size.

Thanks.

 

[FredT]

Posted the list on Diverlink a while back
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parts list:

I’m in the process of converting some old ½” NGT scuba tanks to CGA540 valve oxygen bottles. The items are all part of the Sherwood industrial gas product line. The pricing below is what I paid LAST TIME.

1. CGA 540 valve outlet x ½” NGT brass valve. These COME O2 clean! ~$19.00 each
# TV5441-32 (2015 pressure rating)
# TV5441-35 (2250 pressure rating)
Other pressure ratings are available on request

2. Line valve ¼”NPT male/female (suitable for fill and transfer whips) These come either with a panel nut and threaded stem body, or without, and chrome plated or not. Internals interchange.
# YVA 3010 (no panel nut, chrome plated) ~ $18.00 each

3. The rebuild kit for the above valve has all the parts necessary to completely rebuild 10 Sherwood line (or Scuba) valves except the knob and stem. The normal SCUBA valve kit also has the 214 tank mating o-rings and –014 yoke o-rings this kit doesn’t have, but it’s not available through the industrial vendor. It also costs about twice as much for ~$3.00 worth of O-rings. The –214 and –014 are the only 2 rings that have to be changed to Viton in order make a Sherwood SCUBA valve O2 safe, so I don’t normally need them anyway. ~$30.00 per kit

4. 100 psi fixed output O2 safe pressure reducing regulator. This reg is used to reduce the pressure of O2 from tank pressure to 100 psi (It’s also available in other pressures up to 150 psi) It’s a brass regulator with a carbon steel spring, so you could take it subsea ONCE in case of emergency deco requirements. It’s also inexpensive enough to be disposable if the world turns brown and it has to take a seawater bath. I use it as an O2 source choke for deck deco and emergency O2 delivery. The reduced IP allows use of most second stages as a demand delivery valve. ¼”NPT both ends.
#YR 3710-100


5. Hand wheels and tailpieces to match the CGA540 valves. ~$12 per set

From an industrial supply house

6. 0-3000 psi O2 safe stem gauge

7. SST 1/4"NPT street tee

8. needle valve flow control if doing constant flow masks

From Divers supply

9 Long secod stage hose if doing Scuba regulator demand system.

1/4" NPT to 3/8"-24 SAE adaptor bushing.

FT

 

[Stone]

Ebay almost always has emergency O2 tanks w/ regulators up for bid at a fraction of the cost of DAN's kit.

Be aware that average emergency O2 tanks like "D" and "Jumbo D" only last 30 to 45 min (depending on delivery rate, or in the case of a demand regulator, SAC), but they are very portable and you can get them filled at medical supply places.

Converting a scuba tank to O2 is very practical if portability is not a concern. For example, if the tank stays on the boat and you need enough oxygen to last more than an hour (an AL80 may last up to 1.5 hours even if it is only filled to 2000 psi). You may have to look around for someone willing to fill a scuba tank with pure O2.

Oxyhacker's book has a lot of information on converting different tanks.

 

[divedude]

What I do is rent one.I get it at a medical supply place that rent's to out patients. The cost for the jumbo D is $2.75 a month, filling is $25 which if you don't use it, is a once a season cost. The regulator is $13.50 a month. And the beauty is: at the end of the season you take it back, they service it, refill it and you get it again at the start of the new season, good as new.

This is Canadian prices and our season is a "little shorter" then down south

 

[FredT]

Most of those are fixed flow regs suitable for canula delivery. These are effectively worthless for treating bent divers as they don't put out enough flow to give the diver 100% O2 in each breath.

If I remember correctly that takes about 15 liters per minute minimum, most of the canula rigs deliver about 7lpm.

A few are even the aluminum regs that have been recalled due to potential flame problems...

Do your homework and you can come out OK, but it's bad to _think_ you are prepared, then find out that what you were counting on is not suitable for the job to be done. A O2 rig with a max flow too small is like carrying a .22short derringer or .25ACP for self defense. When the world turns brown it may be better than nothing, but not by much.

This is also something to check out when renting a rig.

Also be sure to have enough O2 handy to get 2 victims to help. Off the MS coast where good diving may be 60 to 90 miles offshore it can be a couple hour run just to get within USCG helicopter rescue range of the beach. A single 72 converted to O2 will usually last a single victim about an hour and a half. If you have a long run better carry extra bottles. The 3/4" straight threads of most newer scuba bottles do not have a single valve conversion solution. CGA specifically did not want O2 valves to be put onto scuba cylinders of unknown cleanliness, so a 3/4-14SPT valve is simply not offered as a standard. It is possible to rethread a 1"NGT valve to fit a 3/4"-14SPT scuba bottle, but machining that thread is expensive unless doing several dozen of them to spread the cost fo the tooling. A 1/2"NGT or 3/4"NGT (tapered) thread tank can be converted directly to O2 (CGA540 or CGA870 connection) once properly cleaned for under $20. It can be refilled at most welding supply houses that use dewar storage without dealing with the prescription hassles if the tank has a 540 connection. CGA870 is normally used for small volume medical and aviaton, CGA540 is used for bulk medical and commercial (welding) O2.

FT

 

[JT2]

Do yourself a favor and purchase Vance Harlow's "Oxygen Hackers Companion" book. This book is absolutely awesome and will answer all of your questions about building an O2 kit as well as many many other things concerning fill stations, gas mixing, O2 cleaning, etc.etc.etc. Trust me, buy the book, you won't regret it. I think you can get it at www.airspeedpress.com

 

[The Iceni]

FredT once bubbled...
Most of those are fixed flow regs suitable for canula delivery. These are effectively worthless for treating bent divers as they don't put out enough flow to give the diver 100% O2 in each breath.

If I remember correctly that takes about 15 liters per minute minimum, most of the canula rigs deliver about 7lpm. . . FT

I'm no expert, however I can confirm that you need a regulator and first stage that can deliver greatly in excess of 15 lpm.

During the breathing cycle the peak flow can exceed 600 lpm for a short time (recognised as the PEFR, peak flow, or peak expiratory flow rate.) While this is a measure of peak expiration it follows that unrestricted inspiratory flow can approach or exceed this level and, indeed, most diving regulators can deliver this amount of gas.

I would therefore recommend caution if divers consider constructing their own unit as they may find their casualty can "beat the valve" and so does not obtain the maximum benefit of the available oxygen.

I must add that while DAN's recommended unit can cope with such high peak flows, employing a regulator/mask system is much more efficient overall than any constant flow system delivering even 15 litres per minute, at least half of which is wasted.

Oxygen cylinders and adaptors

As Fred states, one of the major problems rescuers encounter is the limited size of the oxygen reservoir. The medical "D" cylinder will only provide enough oxygen for less than 30 minutes. In consequnce many British clubs use an additional, standard cylinder, such as a 15 litre, oxygen clean, 232 bar cylinder (DIN or A Clamp) with a suitable pin-index adaptor from Subaqua Services. Such an adaptor dispenses with the need for any special re-engineering and a standard DIN/A clamp fitting makes refilling easier!

See http://www.subaqua-products.co.uk/adaptors_3.htm

I used 100% oxygen for deco and carried one of these DIN/Pin-index adaptors in my kit so, if needed, I could connect the oxygen set to my deco cylinder. It would also allow me to use any back-gas Nitrox should all the oxygen on board be exhausted.

The first stage of the medical regulators available on the British Market can easily take 232 bar but the adaptor devices are not recognised "CE" by the European Union and I am not even sure if they are available to the US market but when lives are at stake I think common sense should prevail!

 

[pt40fathoms]

One way to greatly extend the delivery time of the smaller oxygen bottles is to use a Surface Oxygen Rebreather. http://www.frogdiver.com/surface.html We are 1.5 hrs. from the nearest hospital at our dive site, and this is one device we will be purchasing this spring. We hope never to use it, but if we do need to provide oxygen it only makes sense to be able to provide it for the entire trip to the hospital.

 

[Genesis]

you absolutely want a demand-valve system of some kind for diving O2.

If the victim is unconcsious, then you have bigger problems. But if they are not, then you want some kind of demand valve - either the DAN-style one or a scuba-style one.

 

[mddolson]

It's not rocket science.

1) check out the commercial units and kits available on market.
2) make a list of what you want.
3) Instead of the fancy pelican case, I substituted a large plastic too box and put my DAN stickers on it.
4) I bought everthing I needed on eBay,
used Aluminum tank with valve, hydro'd and filled after it arrived. New regulator, new air-ways, Masks etc. all at about 1/3 price of DAN kit.
5) Downloaded quick check list form Scubdoc, printed and had it laminated for field use.
6) Cut out some particians in the upper too box tray to fit first aid items.
7) Cut a foam liner to fit cylinder and regulator for bottom of kit.
8) added a zip lock bag with quarters and emergency numbers.

Done