feed an O2 face-mask from a scuba first stage?

[rhlee]

Sorry if this is the wrong forum, but it seemed that the gas guys would most likely know the answer here...

I'm wondering if anybody has every heard of feeding an O2 facemask from a normal first stage... Reason I'm asking is that I occasionally have O2 deco bottles on-hand, and I have extra first stages lying around.... so if the connection can be made easily, I'd like to hook up a flow-restrictor and face-mask to a first stage and keep it in the car "just in case".

Any ideas on how to make this work?

 

[Scuba Duck]

The low pressure output of your standard scuba regulator is about 125psi. You could hook a throttling valve, or orifice restrictor to the low pressure hose to control the flow rate to your mask. You still need an oxygen serviced regulator to do this.

If you used a low pressure inflator to 1/4 NPT adapter (available at most dive shops), the mask and throttling device would be removable.

You could do it with three relatively inexpensive parts, BC inflator to 1/4 NPT fitting, needle valve, 1/4 npt to hose barb. The needle valve will allow you to deliver as much or as little oxygen as required for the situation. The tubing to the mask would just push onto the hose barb.

You can get needle valves and the hose barb from mcmaster-carr. If you don't know what size tubing the mask uses, you should be able to get the 1/4" NPT to hose barb fitting at your local hardware store.

McMaster-Carr

 

[oxyhacker]

If by mask you mean a medical mask, like a non-rebreather mask, no problem. I do it using a cheap surplus column flowmeter, the kind that has a needlevalve on the bottom. Connect it to an LP port using an adaptor made from a brass hardware store flare fitting, and you are ready to go. See Cale's Swiss Army Knife at Untitled Document for details.

Remember though that medical masks tend to deliver less than the ideal 100%, and must be used with wastefull flow rates to get even above 90%. If the person being treated is concious and breathing OK, you are better off putting them on a medical demand mask, or a scuba 2nd, as it will give a higher FO2 with better tank duration.

 

[pescador775]

I use a medical regulator, the chrome plated brass type with modular components. I removed the CGA 540 pipe and installed a yoke which was originally part of a SCUBA pressure gauge. The regulator came equipped with the gauges and built in restrictor.

Lots of folks buy the forged, aluminum regulators because they are compact and slick in appearance. However, the modular, chrome regulators from the 1980's are extremely versatile and can be used for several purposes such as mask and NITROX stik. I drilled the body on that one and installed a relief valve to prevent oxygen flow from exceeding safe limit to my compressor. I bought six at EBay auction, brand new, 35 bucks + shipping. At that price, they can be used for trading stock or given away and they are great fun to play with.