Doc Bruce - DIY Oxygen system

bstratt

bstratt

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Bruce, a while ago you posted instructions on how to put together one of your own oxygen systems after purchasing the parts which if I remember ended up costing about half the commercial package. Could I ask you to re-post that? Thanks
 
Re: Doc Bruce - O2

bstratt said:
Bruce, a while ago you posted instructions on how to put together one of your own oxygen systems after purchasing the parts which if I remember ended up costing about half the commercial package. Could I ask you to re-post that? Thanks
Click to expand...
Not Bruce, but that one was a keeper. Here is his old post ...

Go to a welding shop or a medical supply shop and BUY outright the biggest Aluminum cylinder you can- a Super "D" or 50 cu. ft. Why? Because a fill of the smallest compared to the biggest runs the $13.00 up to $18.00. Getting the fill is the inconvenience.

Buy a stepdown regulator (welding type) for ~$40 and put it on top. Buy an 8 foot piece of 80 PSI hose and the appropriate CGA 540 fittings (or have the shop do it for you) and run from the end of the stepdown regulator to another CGA 540 fitting. At this end, buy a Skyox regulator and install it. The Skyox regulator is expensive ($200) but is a precision machined device that automatically doubles flow if two are plugged in, triples for three, etc. It doesn't leak and it's near bulletproof.

Now you have a tank strapped down in the baggage compartment, and complete control in between the PIC seats.

This way you have 1) huge O2 supply, = 30 man hours at 18,000 on cannulas e.g, more than you have fuel, and on some trips you will be able to make the return w/o a refill.

Fill it at your local welding shop. Yes, I know all about ABO, but they all come from the same 25,000 gallon tank. Even medical oxygen, too.

I also carry a 19 cu ft. steel tank that is labeled "ABO" for that emergency refill at an FBO. I use it when I have six on board (The Skyox has four ports). Total cost will be about $300. And, I spend ALL my time in the oxygen altitudes.

I agree with the advice to buy a pulse oximeter. It's the cheapest monitor for the only master processor w/o a backup device- your head. There's nothing from King or Garmin near the price...well, maybe a blind encoder.
 
Re: Doc Bruce - O2

That one needs a permanent home here at POA ... where should it go? Maybe Bruce can save it in "Member's Hangar" (can docs go there?)
 
Re: Doc Bruce - O2

bstratt said:
Thanks Ken
Click to expand...
Only thing that's changed is now the fill is $29. Airgas bought out BOC and now there's no competition. Still, I made my PIA-OAK-PIA trip on a single fill of the main tank! Can you say hours at FL 190?
 
and if you are really cheap but still want to breath for less than 100$....

I bought an aluminum medical E tank (680litres/24cuft/26" tall/10lbs) with regulator and flowmeter for $50 off ebay
http://search.ebay.com/oxygen-tank_W0QQfkrZ1QQfromZR8
and then got tubing and Y connector from a local med supply house ($8) plus a pair of regular cannulas ($5.65 each)
http://www.aircraftspruce.com/catalog/pspages/aeroxsys.php

Without the fancy cannulae and more precise/conserving flowmeter you waste O2 but I get it almost for free :) so the only downside is more frequent fillups. It will keep the two of us in the pink for most long xc's and back.
 
Let'sgoflying! said:
and if you are really cheap but still want to breath for less than 100$....

I bought an aluminum medical E tank (680litres/24cuft/26" tall/10lbs) with regulator and flowmeter for $50 off ebay
http://search.ebay.com/oxygen-tank_W0QQfkrZ1QQfromZR8
and then got tubing and Y connector from a local med supply house ($8) plus a pair of regular cannulas ($5.65 each)
http://www.aircraftspruce.com/catalog/pspages/aeroxsys.php

Without the fancy cannulae and more precise/conserving flowmeter you waste O2 but I get it almost for free :) so the only downside is more frequent fillups. It will keep the two of us in the pink for most long xc's and back.
Click to expand...



Yep I'm cheap too! I did the same thing, after reading this thread.

What L/min settings do you use on the regulator?
Is there any optimal rate for specified altitudes?
I'm doing this, because I'd like to fly at night, without getting dull.....
..............................................................(I've tried the latest jokes, but the passengers still tend to groan....):rofl:

Seriously.... I want to avoid any chance of hypoxia, or even that headachy tired feeling. :(

TIA!
 
Chache said:
Yep I'm cheap too! I did the same thing, after reading this thread.

What L/min settings do you use on the regulator?
Is there any optimal rate for specified altitudes?
I'm doing this, because I'd like to fly at night, without getting dull.....
..............................................................(I've tried the latest jokes, but the passengers still tend to groan....):rofl:

Seriously.... I want to avoid any chance of hypoxia, or even that headachy tired feeling. :(

TIA!
Click to expand...

I strongly recommend that anyone using O2 at altitude (and for that matter anyone who flies above 10,000 MSL for more than an hour) gets a Pulse Oxymeter to check their O2sat. Since everyone is different and many folks react differently from one day to the next, you either have to be very conservative on your O2 flow rates or measure whether or not you are getting enough.
 
Good advice Lance,
I'll do that too.

But I'm only going about half, that high.. Just doing local fun trips, at night, around 4000-4500 feet. O2 there.... can't hurt.
 
Chache said:
Good advice Lance,
I'll do that too.

But I'm only going about half, that high.. Just doing local fun trips, at night, around 4000-4500 feet. O2 there.... can't hurt.
Click to expand...
With the Pulse Oximeter only costing the same as four fillups, it's clearly worth it. $150 was the last I've seen....
 
Chache said:
Yep I'm cheap too! I did the same thing, after reading this thread.
What L/min settings do you use on the regulator?
Is there any optimal rate for specified altitudes?
Click to expand...

Hi Chache, I have been testing the minimum required to maintain safe PO2 levels, usually I start pulling it out at 11000 (if it looks like more than a half hour) as my own PO2 stays in the nineties til then.
Above there, the highest I can get even with max flow rates and breathing techniques is 92-94%. I have brought it down to a half liter a minute per person, between 12 and 15000 and O2 has never dropped below 92% if I am paying attention to breathing. I haven't had the nerve to go below 500ml/min.
Between 15 and 18K (data is sketchy here; only a few points so far), I have had the O2 at 750 to 1000ml/min/person with similar %s but have not had the nerve to go lower.
I agree with the Requirement for the Oximeter, other wise you may have NO indication there is a problem. If the battery on mine were to fail above 15K I am going to descend.
 
I am thinking of following Bruce's advice on building my own O2 system. Can you give any advice on which pulse oximeters to look at?

Thanks

Pete
 
vontresc said:
I am thinking of following Bruce's advice on building my own O2 system. Can you give any advice on which pulse oximeters to look at?
Click to expand...

Someone worked a deal for those on the old AOPA board to get 'em cheap - I forget what model, but it was $150. Unfortunately, that page (and presumably that deal) no longer exists. :(

It was from these folks, and they have several models for sale:

http://www.turnermedical.com/Finger_Oximeters.htm

Cheapest is $189. Want to go in halves on it, and we can leave it in the locker at the airport?
 
flyingcheesehead said:
Someone worked a deal for those on the old AOPA board to get 'em cheap - I forget what model, but it was $150. Unfortunately, that page (and presumably that deal) no longer exists. :(

It was from these folks, and they have several models for sale:

http://www.turnermedical.com/Finger_Oximeters.htm

Cheapest is $189. Want to go in halves on it, and we can leave it in the locker at the airport?
Click to expand...


I've recently bought one. If you use this link, it is still $150:

http://www.turnermedical.com/cessna.htm
 
bstratt said:
Bruce, this link seems to indicate a preference for Aerox as opposed to Skyox (piston vs diaphragm, flow indicators, etc.).

http://www.aviationoxygen.com/compared.html
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I can only tell you that my two Skyox regulators have been flawless through repetitive use, since 1993. Not too bad. The Aerox may be excellent, too- just no personal experience behind any comment I might make.
 
Re: Turner Medical

Mike Schneider said:
Thanks, El Paso Pilot, I just purchased a second one. I gave my first one to my daughter and thought the $150 deal had gone away (because I checked last week and only could find the $189 price). I was kicking myself for not writing down when the end of the sale was to occur. When I last saw the ad, I think it had an ending date, but I note there is no ending date on the present ad (at least, I couldn't find one). Thanks again, El Paso Pilot. -- Mike
Click to expand...

No problem, Mike. I found the link on an old search on the red board and bought mine. There is no way to click to it on Turner's current site, but they are apparently still honoring the price if you type it in directly.

By the way, my first one died on its maiden trip, but they replaced it no questions asked, paid for postage both ways, and the second one seems to work fine. Nice to see customer service still lives once in a while.
 
Let'sgoflying! said:
Hi Chache, I have been testing the minimum required to maintain safe PO2 levels,
I agree with the Requirement for the Oximeter, other wise you may have NO indication there is a problem. If the battery on mine were to fail above 15K I am going to descend.
Click to expand...

Thanks LGF...
I had bypass surgery x3, more than 5 years ago, but no problems since. I "ACED" :target: all my Special Issuance tests, with numbers of
a man some 20 yrs younger...and I now have a 3rd class, with yearly retests. I have no problem with that either.

I just want to be as healthy as I can possibly be.
( and it's said that Pilots are by far, healthier than ordinary folk.)

Still in flight school, and looking to solo soon.
(finally, after some 50+ years (already?) of "One day ...Soon" ..wishing.)

I have been @ 4500' at night, with another pilot, for three hours. No issues there, no 02 either either.
Just slightly tired upon arriving home. That may have been just from a long day, and old age......
But I read an article, in AOPA magazine about headachy-ness, and feeling tired and their recommendation
for supplemental O2, at 5000' and above at night.

I decided right then, this is for me, as is the P-O2meter,
if for nothing else other than, monitoring the changes.

But I couldn't see the prices advertised, for O2 systems.:no:
It's as outrageous as Gasoline:yes:

Chache
 
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It's hard to see how they could save $$s and make it junk. Basically, it's two photocells gated to that part of the spectrum that's phasic. It goes to a lookup table for the two wavelength OD's and displays a value.

2% is more "loose" than others, but then I'd have to maintain 92% rather than 90%, which takes a smitch more O2. But something is better than nothing, for sure.
 
Be careful purchasing old or used aluminum pressure cylinders, if left on their sides for long storage periods, they can corrode on the inside from the moisture that accumulates over time.

An old divers trick is to tap around the parameter of a cylinder with a coin about every inch or less. The sound should be the same with every tap. If the tone changes, discard or don't purchase it, especially if the sound change sounds like a "clunk". I know aviation ox isn't supposed to have water in it, but is that a written guarantee?

John
 
John Baker said:
Be careful purchasing old or used aluminum pressure cylinders, if left on their sides for long storage periods, they can corrode on the inside from the moisture that accumulates over time.

An old divers trick is to tap around the parameter of a cylinder with a coin about every inch or less. The sound should be the same with every tap. If the tone changes, discard or don't purchase it, especially if the sound change sounds like a "clunk". I know aviation ox isn't supposed to have water in it, but is that a written guarantee?

John
Click to expand...
How much trouble have you seen with corroded aluminum cylinders? My guess is none whatsoever.

Aluminum alloys used in compressed gas cylinders do not corrode. Are you sure you are not talking about old steel cylinders?

Even if they are steel the chances of getting moisture inside is pretty slim to none. Anytime a cylinder is filled with a pressurized gas that gas has passed through several stages of compression and drying. The only way for moisture to get in is if the cylinder was left without pressurized gas in it and the valve was left open. But as I said before that would only be a problem if the cylinder is steel.

BTW I am an old diver and I have never heard of nor would I trust that penny trick. The easiest thing to do is open the cylinder by removing the valve and looking into it with a light and a small mirror.
 
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My brother is a diver, I learned the coin trick from him. About a year ago I tested a small tank at San Diego Divers Supply, and got, what sounded like a definite tone change on one side. The guy showing it to me scoffed at my "test", I didn't buy it anyway.

It is obvious that I am not an expert, but there was a tone change the full length of the tank about an inch or so wide. My brother only used aluminum tanks and seemed to know what he was talking about, at least it made sense to me.

I will continue to use the coin test, even though I now know it is probably a stupid idea. Usually when I look at used tanks I never seem to have a wrench, a light, and a small mirror with me. I do, however, normally have some spare change in my pocket.

John
 
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John Baker said:
My brother is a diver, I learned the coin trick from him. About a year ago I tested a small tank at San Diego Divers Supply, and got, what sounded like a definite tone change on one side. The guy showing it to me scoffed at my "test", I didn't buy it anyway.

It is obvious that I am not an expert, but there was a tone change the full length of the tank about an inch or so wide. My brother only used aluminum tanks and seemed to know what he was talking about, at least it made sense to me.

I will continue to use the coin test, even though I now know it is probably a stupid idea.

John
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I'll stick with visual inspection and mag-resonance testing since I was certified by Luxfer to do those things, have the equipment, and do that testing at the dive shop I work at, etc.

Like I said Al alloy used in tank = no corrosion problem, steel can and does corrode with stored improperly i.e. not pressurized.

Your penny test may be giving you a tone change for another reason. Steel tanks are made from a plate of steel that is rolled and welded. You could simply be tapping on the weld. Or you could simply be hitting a part of the paint on the outside that is starting to separate from the metal, a very common thing.

In all the steel tanks I have inspected the only ones I have ever dinged for a problem were some old tanks that were painted on the inside. These were popular in the late 60's and 70's. The paint can start to de-bond from the tank walls.

Al tanks I have dinged but for unseen cracks in the tank valve area. That is what the magnetic resonance test is for.

Seriously. I would not bet on a penny test to tell me anything good or bad. You need to do a visual test on any tank, if it is out of it's hydro range you should get that done. If the tank is Al have the mag-resonance test on the valve to make sure you have no cracks.
 
John Baker said:
they can corrode on the inside from the moisture that accumulates over time....................

I know aviation ox isn't supposed to have water in it, but is that a written guarantee?

John
Click to expand...

If the tank is under pressure, please explain to me how moisture gets IN and accumulates?

As for written guarantee, pretty much if you get it from the source YES. If you get a medical tank with a medical fill, YES. If you never let your tank go dry, and you fill it from tanks you dont let go dry. YES.

Welders oxygen, medical oxygen, aviation oxygen and industrial gas oxygen all comes from the same tap nowadays. Even if the technical specs differ between the different labels, the supply stream meets or exceeds each and every one of them. They cryogenically distill it, then store it as a liquid. If the end user wants compressed gas, they vaporize it, compress it and place it in a tank. They may be filling welding tanks next to aviation tanks.. it doesn't matter, the same stream meets the specs.

NO oxygen is supplied under pressure in a tank with any appreciable moisture or it would corrode the tank in short order, not to mention freeze in the regulator when it was dispensed at a working pressure. That's from 2200 psi max to about 50 PSI over ambient. Universal gas law applies - PV=nRT. Big pressure drop on one side of the equal sign means big temp drop on the other side, all other things constant.

And when I say NO oxygen has appreciable moisture, that includes medical oxygen. Humidification is added OUTSIDE the tank before delivery to the patient.

Medical oxygen is actually under the strictest standards now, and has been for about 10 years now. The tanks have serial numbers, are tracked, and after EVERY use are evacuated to vacuum before being refilled. Part of this is because medical tanks have a pretty bad habit of being run empty then left open to atmosphere, allowing contaminants to slowly ease in during subtle atmospheric changes.

The best insurance against keeping your tank clean is to never run it dry/empty. A term used in my paramedic class was "safe residual" pressure which was intended to be a number we never let the tanks go below.. about 200 psi. This is old school though, before the days of FDA requiring tank serial numbers and filling at the gas plant rather than by the end user.
 
My rig.. was going to be a firefighters breathing air tank - fiberglass composite wrapped around an AL core. The bottles have a 15 year life, which is overly conservative based on duty cycles. The bottle carries enough air to support a firefighter for 30 mins. When used for oxygen it can be trickled out much more slowly and in theory could support 4 peeps for up to 5 hours out and back. And still weigh less than an aluminum D tank.

Standard regulator, remote pressure gauge.

It almost completely eliminates the need to refill away from home for an out and back mission. And weighs less. Whats not to love. You do lose about 2.5 cubic feet of space in your cargo area, but its so light you could actually mount it behind the aft baggage area in a conventional plane and not incur a major penalty.
 
vontresc said:
I am thinking of following Bruce's advice on building my own O2 system. Can you give any advice on which pulse oximeters to look at?

Thanks

Pete
Click to expand...

I just bought a Devon FDA approved Oximeter for about $60. The link is on the Cumulus Soaring Web Site.

Seems to work Ok, I don't have anything to compare it to. I liked the LCD display as it is very visible in sunlight.

Brian Case
 
DIY Oxygen system

Has anyone found an economical way to fill our oxygen bottles? I usually only need a top off before a trip and $35-40 is just wrong! :no:
 
Re: DIY Oxygen system

flyingriki said:
Has anyone found an economical way to fill our oxygen bottles? I usually only need a top off before a trip and $35-40 is just wrong! :no:
Click to expand...
I fill at the local welding supply or a nearby scuba shop that buys big cylinders of welding O2 for scuba. The most I have ever paid was $12/fill
 
Re: DIY Oxygen system

flyingriki said:
Has anyone found an economical way to fill our oxygen bottles? I usually only need a top off before a trip and $35-40 is just wrong! :no:
Click to expand...
The key is to have TWO bottles. Run one just about right down and refill it right away. Then you don't fly with partial bottles, and you always refill and get a near full load.
 
Re: DIY Oxygen system

flyingriki said:
Has anyone found an economical way to fill our oxygen bottles? I usually only need a top off before a trip and $35-40 is just wrong! :no:
Click to expand...

VERY economical way is to rent two BIG cylinders - a few years back it was like 12-15 bux per tank. You can link them together or you can have separate fill hoses.

Use one big tank and fill the receptacle tank as much as possible, until they equalize. Fill slowly. Crack open the valve on the big tank and let them equalize. The receptacle tank will heat from filling. the faster you fill, the hotter it gets and the less full you will be able to fill the receptacle.

Then close the first big tank, which is now less than full. Open the second full tank and top the receptacle tank off. You will end up using the same volume of gas as simply equalizing all 3 tanks, but using the above method, called "cascading" in the gas industry and fire service, you get higher pressures in the receptacle.

I have extensive experience with this setup, in fire depts and in EMS back when medical oxygen wasn't required to be filled by the vendor from a vacuum. We used a 4 tank cascade and could all but fill the receptacle tanks at 2100-2200 PSI. Chances are, they FBO uses this very same arrangement to fill your tank and charge through the nose for the favor.

Once the 1st tank gets below 1000-1500 PSI its pretty much not useable for cascading but you can still use it for torch/welding work... or you can just waste it and turn it back in. You can rent 2-3 large tanks and chain them to your wall for less than the cost of 2 oxygen fills at an FBO.
 
Re: DIY Oxygen system

Doggtyred said:
VERY economical way is to rent two BIG cylinders - a few years back it was like 12-15 bux per tank. You can link them together or you can have separate fill hoses.
Click to expand...

Is that $12-15 per month? Around here you have to put down a substantial deposit or pay a monthly rental fee in addition to the fill charge (cheap). You also need the cascade plus a filling adapter and they aren't cheap. I've considered going this route but right now I'm only going through a couple $15 fills (welding supply) per year so I don't think I'd save any money with my own set of bottles.

BTW, I wouldn't fill a bottle unless it was inside a tub of water. You also have to be very careful about getting anything combustible (oil from your skin etc) on anything that might come in contact with high pressure O2.
 
Re: DIY Oxygen system

gismo said:
BTW, I wouldn't fill a bottle unless it was inside a tub of water. You also have to be very careful about getting anything combustible (oil from your skin etc) on anything that might come in contact with high pressure O2.
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Filling inside a tub is a very archaic way of doing fills.

A long time ago (20 years), it was thought that keeping the tank in the tub would keep the tank cool and reduce stress of the metal. But that idea was based on purely anecdotal evidence.

Testing of tanks showed that it did not accomplish anything but help get little droplets of water into the tank from when the inlet was accidently doused with the water jsut before the fill whip was put on.

Nowadays dry filling is very common. Fills are done slow enough if they are manual or by using a fill profile based on pressure reading to see how fast they drop which is an indicator of cooling of the tank.

Cylinder manufacturers indicate that until an Al cylinder reaches 265F you do not have to worry about temperature damage. Even in a fast fill your tanks will not get this hot. You can still touch them with your bare hands and not get injured. Steel is even more forgiving. Steel is often, but not by me, overfilled with no ill effects. Personally the rating of the tank is there for a reason and I follow it, but I know a lot of people who over fill and I am not talking about a 10%, which is allowed overfill, I am talking 30% - 40% overfills.
 
Re: DIY Oxygen system

gismo said:
Is that $12-15 per month? Around here you have to put down a substantial deposit or pay a monthly rental fee in addition to the fill charge (cheap). You also need the cascade plus a filling adapter and they aren't cheap. I've considered going this route but right now I'm only going through a couple $15 fills (welding supply) per year so I don't think I'd save any money with my own set of bottles.

BTW, I wouldn't fill a bottle unless it was inside a tub of water. You also have to be very careful about getting anything combustible (oil from your skin etc) on anything that might come in contact with high pressure O2.
Click to expand...

If you only fill your bottles 3-4 times a year you will not save a dime using this method. But you will have the convenience factor in your favor. If you are filling once a month, you will save money.

I don't believe the tank rental values I gave were monthly I believe it was per tank. The information is a bit dated. For curiosity sake I may swing by a gas house and just ask the current prices. My data is about 3 years old.

As for VERY careful, true.. you have clean hands, no hydrocarbons on the fittings and take your time. Its not rocket science though. You don't need a high school diploma to do the task safely, you just have to be capable of following SIMPLE instructions. Think about it.. the line boy filling your tank likely isn't a rocket scientist either (but might be taking coursework to be one... :lol:)

As for what what another said regarding "wet" fills... The only folks I've seen doing wet fills in the past 20 years are scuba shops. I was doing dry fills on fire scenes and in fire stations 20 years ago.

Its not uncommon to fill in a blast vessel (essentially a section of large steel pipe that redirects shrapnel from a burst, and holds the tank still) but it rates about with an ELT.. rarely needed, and only works half the time when you do need it.
 
I purchased a 15 cf aluminum tank and have a 40cf steel tank sitting. Any advice on where to purchase some set up to fill from the 40cf? I don't see us on oxygen often but it will be nice to have, just in case.

The FBO at Wilmington wanted $50 to fill the tank (15cf) and I told them they were crazy! I said all the 100LL fuel I buy out of this place and that's the best you all can do? After a brief discussion they said $25 and even though I thought that was still a bit high I had them fill the tank. I didn't want to wait until the following Monday when the welding shop would fill it.
 
BTW, I wouldn't fill a bottle unless it was inside a tub of water.
Click to expand...
As Smigaldi said, dry fills- even really fast dry fills are not risky. I used to be a volunteer firefighter and have done a few thousand SCBA tank refills over the years without a single problem, nor have I ever heard of one that actually came down to the issues you're talking about (failure of an otherwise structurally sound tank during a responsible filling).

(oil from your skin etc) on anything that might come in contact with high pressure O2.
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No offense, but I get the feeling you've never worked around O2 for any length of time. I trans-fill portable O2 bottles (and liquid O2 systems) at work all the time and never had had anything approaching an issue. Now, I would not recommend having grime, dirt or anything hydrocarbon (petroleum) derived on your hands and doing it, but the oil from your skin is not going to combust if you have 100% O2 blown over it (otherwise my hands would get burned every day at work) or if you touch a warm tank. About the only major risk for burns comes from patients or well-intentioned nurses who rub petroleum jelly into the nostrils of someone receiving O2 by cannula

The only folks I've seen doing wet fills in the past 20 years are scuba shops.
Click to expand...

I haven't seen a dive shop doing a wet fill for several years now, but your mileage apparently varies.
 
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