Affordable Oxygen

On Wednesday, January 22, 2020 at 1:15:33 PM UTC-7, wrote:
On Wednesday, January 22, 2020 at 10:26:40 AM UTC-8, John Foster wrote:
I was given an older MH EDS unit to install in my Phoebus glider which I got for a song and am restoring. The glider has a bracket for the oxygen tank, but no tank is installed. The bottom is a rounded fiberglass cup, and there is a flip bracket to go around the neck. It sits behind the seat pan to the right of the landing gear. The cup measures about 5 1/2" inside diameter, but the felt strip padding inside reduces that somewhat by up to 1/4" or so. The neck bracket is about 16" from where the curve of the bottom cup starts. I THINK (but am not sure) a MH AL647 tank will fit, but it has a flat bottom and I'm not sure how much I far forward I can get the tank in the neck bracket so it will fit, as this tank measures 16 1/2", according the the chart on W&W site. Plus, the tank and a plain regulator will run almost 1/4 the cost of what I paid for the glider. I'm pretty sure I can get a plain D-cylinder to fit, as it is narrower and could fit deeper into the curved cup for the bottom of the tank.

This has gotten me thinking then: is there any reason one couldn't use a standard "yolk-style" primary regulator for the oxygen tank? It would be much more affordable, and easier for me to get one of these style tanks, as I work in the medical field.



On Wednesday, January 22, 2020 at 10:26:40 AM UTC-8, John Foster wrote:
I was given an older MH EDS unit to install in my Phoebus glider which I got for a song and am restoring. The glider has a bracket for the oxygen tank, but no tank is installed. The bottom is a rounded fiberglass cup, and there is a flip bracket to go around the neck. It sits behind the seat pan to the right of the landing gear. The cup measures about 5 1/2" inside diameter, but the felt strip padding inside reduces that somewhat by up to 1/4" or so. The neck bracket is about 16" from where the curve of the bottom cup starts. I THINK (but am not sure) a MH AL647 tank will fit, but it has a flat bottom and I'm not sure how much I far forward I can get the tank in the neck bracket so it will fit, as this tank measures 16 1/2", according the the chart on W&W site. Plus, the tank and a plain regulator will run almost 1/4 the cost of what I paid for the glider. I'm pretty sure I can get a plain D-cylinder to fit, as it is narrower and could fit deeper into the curved cup for the bottom of the tank.

This has gotten me thinking then: is there any reason one couldn't use a standard "yolk-style" primary regulator for the oxygen tank? It would be much more affordable, and easier for me to get one of these style tanks, as I work in the medical field.

Way, way back 22 cf bottles had a rounded bottom that would fit into the cup.

So if I'm hearing everyone correctly, there is no physical reason not to use the yoke style regulator other than how it would fit. There are no significant strength differences or how it behaves at altitude that could be more dangerous with the yoke style regulator. Is that right?

John Foster wrote on 1/22/2020 1:56 PM:

This has gotten me thinking then: is there any reason one couldn't use a standard "yolk-style" primary regulator for the oxygen tank? It would be much more affordable, and easier for me to get one of these style tanks, as I work in the medical field.

Way, way back 22 cf bottles had a rounded bottom that would fit into the cup.

So if I'm hearing everyone correctly, there is no physical reason not to use the yoke style regulator other than how it would fit. There are no significant strength differences or how it behaves at altitude that could be more dangerous with the yoke style regulator. Is that right?

I used one for years with no problems; after all, the bottle has to control
2000psi, so an ambient variation of 8 psi or so isn't going to affect it. I don't
think cold to 0 deg F is a problem, either, as I'm still here, but the
specifications should state the operating range. No, I don't know where to get them.

--
Eric Greenwell - Washington State, USA (change ".netto" to ".us" to email me)
- "A Guide to Self-Launching Sailplane Operation"
https://sites.google.com/site/motorg...ad-the-guide-1

On Wednesday, January 22, 2020 at 4:56:48 PM UTC-5, John Foster wrote:
On Wednesday, January 22, 2020 at 1:15:33 PM UTC-7, wrote:
On Wednesday, January 22, 2020 at 10:26:40 AM UTC-8, John Foster wrote:
I was given an older MH EDS unit to install in my Phoebus glider which I got for a song and am restoring. The glider has a bracket for the oxygen tank, but no tank is installed. The bottom is a rounded fiberglass cup, and there is a flip bracket to go around the neck. It sits behind the seat pan to the right of the landing gear. The cup measures about 5 1/2" inside diameter, but the felt strip padding inside reduces that somewhat by up to 1/4" or so. The neck bracket is about 16" from where the curve of the bottom cup starts. I THINK (but am not sure) a MH AL647 tank will fit, but it has a flat bottom and I'm not sure how much I far forward I can get the tank in the neck bracket so it will fit, as this tank measures 16 1/2", according the the chart on W&W site. Plus, the tank and a plain regulator will run almost 1/4 the cost of what I paid for the glider. I'm pretty sure I can get a plain D-cylinder to fit, as it is narrower and could fit deeper into the curved cup for the bottom of the tank.

This has gotten me thinking then: is there any reason one couldn't use a standard "yolk-style" primary regulator for the oxygen tank? It would be much more affordable, and easier for me to get one of these style tanks, as I work in the medical field.



On Wednesday, January 22, 2020 at 10:26:40 AM UTC-8, John Foster wrote:
I was given an older MH EDS unit to install in my Phoebus glider which I got for a song and am restoring. The glider has a bracket for the oxygen tank, but no tank is installed. The bottom is a rounded fiberglass cup, and there is a flip bracket to go around the neck. It sits behind the seat pan to the right of the landing gear. The cup measures about 5 1/2" inside diameter, but the felt strip padding inside reduces that somewhat by up to 1/4" or so. The neck bracket is about 16" from where the curve of the bottom cup starts. I THINK (but am not sure) a MH AL647 tank will fit, but it has a flat bottom and I'm not sure how much I far forward I can get the tank in the neck bracket so it will fit, as this tank measures 16 1/2", according the the chart on W&W site. Plus, the tank and a plain regulator will run almost 1/4 the cost of what I paid for the glider. I'm pretty sure I can get a plain D-cylinder to fit, as it is narrower and could fit deeper into the curved cup for the bottom of the tank.

This has gotten me thinking then: is there any reason one couldn't use a standard "yolk-style" primary regulator for the oxygen tank? It would be much more affordable, and easier for me to get one of these style tanks, as I work in the medical field.

Way, way back 22 cf bottles had a rounded bottom that would fit into the cup.

So if I'm hearing everyone correctly, there is no physical reason not to use the yoke style regulator other than how it would fit. There are no significant strength differences or how it behaves at altitude that could be more dangerous with the yoke style regulator. Is that right?

Don't assume that someone else's regulator can be substituted for MH with the MH EDS.

On Thursday, 23 January 2020 03:03:59 UTC+2, Tango Eight wrote:
Don't assume that someone else's regulator can be substituted for MH with the MH EDS.

From Mountain High's website:
"MH Oxygen Regulators are constant-pressure regulators calibrated to deliver 15 -20 psig of dynamic pressure"

Any pressure regulator supplying a constant pressure in the same range should work fine. All the fancy stuff happens in the EDS unit.

Circling back to the OP's comment about price. What is the price of one's life? $600? The same argument can be applied to a functioning parachute and an airworthy aircraft.

...calibrated to deliver 15 -20 psig of dynamic pressure"

Any pressure regulator supplying a constant pressure...

There is definitely a potential surge problem there.

The EDS regulator is special in being designed to switch from no flow to lots and back while keeping the output pressure reasonable.

If you wish to gamble with yourself, then perhaps a surge tank after the regulator to improve the odds. A pulse-ox to keep an eye on the contraption might also be a good idea. But the words 'good idea' might not fit the situation?

On Thursday, January 23, 2020 at 6:15:07 AM UTC-7, wrote:
...calibrated to deliver 15 -20 psig of dynamic pressure"

Any pressure regulator supplying a constant pressure...

There is definitely a potential surge problem there.

The EDS regulator is special in being designed to switch from no flow to lots and back while keeping the output pressure reasonable.

If you wish to gamble with yourself, then perhaps a surge tank after the regulator to improve the odds. A pulse-ox to keep an eye on the contraption might also be a good idea. But the words 'good idea' might not fit the situation?

From what I'm reading, it seems most medical "yoke-style" (CGA870) regulators are rated more for gas FLOW, i.e. Liters per Minute, than for pressure, i.e. PSI. It is hard to find the PSI rating for these medical regulators, but one data point I found was that one was rated at 50psi, which is much higher than the EDS unit is designed to handle. It is the typical regulator where you can dial the FLOW from 0.5lpm to 15lpm. I realize that FLOW and PRESSURE are two completely different animals, but they are related and affect each other. Is there a way to set the FLOW rate to get the PSI at the desired 15-20psi? My gut tells me not really, but my physics is a bit rusty and can't prove it to myself.

John Foster wrote on 1/23/2020 8:40 AM:
On Thursday, January 23, 2020 at 6:15:07 AM UTC-7, wrote:
...calibrated to deliver 15 -20 psig of dynamic pressure"

Any pressure regulator supplying a constant pressure...

There is definitely a potential surge problem there.

The EDS regulator is special in being designed to switch from no flow to lots and back while keeping the output pressure reasonable.

If you wish to gamble with yourself, then perhaps a surge tank after the regulator to improve the odds. A pulse-ox to keep an eye on the contraption might also be a good idea. But the words 'good idea' might not fit the situation?

From what I'm reading, it seems most medical "yoke-style" (CGA870) regulators are rated more for gas FLOW, i.e. Liters per Minute, than for pressure, i.e. PSI. It is hard to find the PSI rating for these medical regulators, but one data point I found was that one was rated at 50psi, which is much higher than the EDS unit is designed to handle. It is the typical regulator where you can dial the FLOW from 0.5lpm to 15lpm. I realize that FLOW and PRESSURE are two completely different animals, but they are related and affect each other. Is there a way to set the FLOW rate to get the PSI at the desired 15-20psi? My gut tells me not really, but my physics is a bit rusty and can't prove it to myself.

I misunderstood you earlier: I thought you were considering a medical bottle with
an adapter that fits typical glider equipment, like an EDS regulator. The EDS
system is an important piece of safety equipment, so please do not try to save
money by substituting components UNLESS Mountain High approves of the substitution.

--
Eric Greenwell - Washington State, USA (change ".netto" to ".us" to email me)
- "A Guide to Self-Launching Sailplane Operation"
https://sites.google.com/site/motorg...ad-the-guide-1

On Thursday, January 23, 2020 at 9:40:13 AM UTC-7, John Foster wrote:
On Thursday, January 23, 2020 at 6:15:07 AM UTC-7, wrote:
...calibrated to deliver 15 -20 psig of dynamic pressure"

Any pressure regulator supplying a constant pressure...

There is definitely a potential surge problem there.

The EDS regulator is special in being designed to switch from no flow to lots and back while keeping the output pressure reasonable.

If you wish to gamble with yourself, then perhaps a surge tank after the regulator to improve the odds. A pulse-ox to keep an eye on the contraption might also be a good idea. But the words 'good idea' might not fit the situation?

From what I'm reading, it seems most medical "yoke-style" (CGA870) regulators are rated more for gas FLOW, i.e. Liters per Minute, than for pressure, i.e. PSI. It is hard to find the PSI rating for these medical regulators, but one data point I found was that one was rated at 50psi, which is much higher than the EDS unit is designed to handle. It is the typical regulator where you can dial the FLOW from 0.5lpm to 15lpm. I realize that FLOW and PRESSURE are two completely different animals, but they are related and affect each other. Is there a way to set the FLOW rate to get the PSI at the desired 15-20psi? My gut tells me not really, but my physics is a bit rusty and can't prove it to myself.

Upon further research, it appears that medical oxygen is standardized at 50psi, both from the portable oxygen tanks, and from the wall outlets in hospitals. This would not work to use a medical oxygen regulator and just "dial it down", as the pauses between breaths, the reduced flow at low altitudes, would cause the pressure to rise between the primary regulator (50psi) and the EDS unit (15-20psi). You would need a secondary regulator between them to step the pressure down to 15-20psi, or you would damage your EDS unit.

On Friday, January 24, 2020 at 10:00:09 AM UTC-8, John Foster wrote:
On Thursday, January 23, 2020 at 9:40:13 AM UTC-7, John Foster wrote:
On Thursday, January 23, 2020 at 6:15:07 AM UTC-7, wrote:
...calibrated to deliver 15 -20 psig of dynamic pressure"

Any pressure regulator supplying a constant pressure...

There is definitely a potential surge problem there.

The EDS regulator is special in being designed to switch from no flow to lots and back while keeping the output pressure reasonable.

If you wish to gamble with yourself, then perhaps a surge tank after the regulator to improve the odds. A pulse-ox to keep an eye on the contraption might also be a good idea. But the words 'good idea' might not fit the situation?

From what I'm reading, it seems most medical "yoke-style" (CGA870) regulators are rated more for gas FLOW, i.e. Liters per Minute, than for pressure, i.e. PSI. It is hard to find the PSI rating for these medical regulators, but one data point I found was that one was rated at 50psi, which is much higher than the EDS unit is designed to handle. It is the typical regulator where you can dial the FLOW from 0.5lpm to 15lpm. I realize that FLOW and PRESSURE are two completely different animals, but they are related and affect each other. Is there a way to set the FLOW rate to get the PSI at the desired 15-20psi? My gut tells me not really, but my physics is a bit rusty and can't prove it to myself.

Upon further research, it appears that medical oxygen is standardized at 50psi, both from the portable oxygen tanks, and from the wall outlets in hospitals. This would not work to use a medical oxygen regulator and just "dial it down", as the pauses between breaths, the reduced flow at low altitudes, would cause the pressure to rise between the primary regulator (50psi) and the EDS unit (15-20psi). You would need a secondary regulator between them to step the pressure down to 15-20psi, or you would damage your EDS unit.

Using medical O2 for aviation is akin to using a vet for your health care, wrong application. The vet might just shoot you for a broken leg.