Precise Flight X3 demand conserver - anyone using one in a Bravo? Will it work?

[Rick Junkin]

Is anyone using an X3, or know if it will work in a Bravo? I have a call in to Precise Flight but with the holiday I don't think I'll hear from them until next week, and I can't find the specs for my regulator online to see if it puts out the required pressure. Avox 803216-03.

Thanks for any input on experience with the X3 in a Bravo.

Cheers,
Rick

[kortopates]

Rick, You should have the Altitude compensating regulator used on all factory equipped Mooney's till they went to the  Precise system much more recently without the altitude compensating regulator (which does work).

As such pressure varies with altitude to save O2 without the use of a flow meter. Precise couldn't answer this question as to whether or not the pressure is sufficient for their X3, at least I've been down this path before and talked to multiple people there that know their X3 system. They suggest trying it and seeing and if you bought it from them, then they'd take back if it doesn't work. I just never got around to testing it. That's all you can really do and note their likley won't be enough pressure on the ground, so actually testing it will likely require a flight to an O2 altitue to test it. At least I wouldn't give up based on a ground test.

But probably someone here on Mooneyspace has already tried it. I asked this very question a few years ago but didn't get answer from any one that has tried it or using it with our system - just the Precise system used in later models. But posting this in the Bravo section may limit the audience you want to reach.

 

[Rick Junkin]

1 hour ago, kortopates said:

Rick, You should have the Altitude compensating regulator used on all factory equipped Mooney's till they went to the  Precise system much more recently without the altitude compensating regulator (which does work).

As such pressure varies with altitude to save O2 without the use of a flow meter. Precise couldn't answer this question as to whether or not the pressure is sufficient for their X3, at least I've been down this path before and talked to multiple people there that know their X3 system. They suggest trying it and seeing and if you bought it from them, then they'd take back if it doesn't work. I just never got around to testing it. That's all you can really do and note their likley won't be enough pressure on the ground, so actually testing it will likely require a flight to an O2 altitue to test it. At least I wouldn't give up based on a ground test.

But probably someone here on Mooneyspace has already tried it. I asked this very question a few years ago but didn't get answer from any one that has tried it or using it with our system - just the Precise system used in later models. But posting this in the Bravo section may limit the audience you want to reach.

 

Thanks Paul @kortopates. What system do you have in your airplane? Ray mentioned you wouldn’t be able to test it until February, but if it’s the same or similar altitude compensating system I have then I’ll be able to give you some data in the next few days. You’re first in line for Ray’s X3s and I’m not butting in front of you if we can determine they’ll work or you.

I ground tested my system today and saw a delivery pressure of 8.5 PSI at 1,000’ PA. I’ll get airborne in the next few days and take it up to altitude to see if it gets to the 20 PSI required to drive the X3. The PO2 about halves at 15,000 so if the regulator is linear in it’s compensation I would only expect 17 PSI but we’ll see what I discover.

Unless of course one of our brethren (or sisteren?) here has first hand experience to share and saves me the trouble!

Cheers,
Rick

EDIT: BTW, I’ve been using Precise Flight A5 flow meters with my system, I’m thinking the onboard altitude compensating regulator errs to the high side so it may very well provide the 20PSI somewhere in the altitude profile.

Edited December 24, 2021 by Junkman
Added detail

[kortopates]

48 minutes ago, Junkman said:

Thanks Paul @kortopates. What system do you have in your airplane? Ray mentioned you wouldn’t be able to test it until February, but if it’s the same or similar altitude compensating system I have then I’ll be able to give you some data in the next few days. You’re first in line for Ray’s X3s and I’m not butting in front of you if we can determine they’ll work or you.

I ground tested my system today and saw a delivery pressure of 8.5 PSI at 1,000’ PA. I’ll get airborne in the next few days and take it up to altitude to see if it gets to the 20 PSI required to drive the X3. The PO2 about halves at 15,000 so if the regulator is linear in it’s compensation I would only expect 17 PSI but we’ll see what I discover.

Unless of course one of our brethren (or sisteren?) here has first hand experience to share and saves me the trouble!

Cheers,
Rick

EDIT: BTW, I’ve been using Precise Flight A5 flow meters with my system, I’m thinking the onboard altitude compensating regulator errs to the high side so it may very well provide the 20PSI somewhere in the altitude profile.

yes mine is the same factory system as described which should match your system, Mooney only used one system till more recently as mentioned. Indeed, my plane is in the shop till Mid January for another panel upgrade plus I am out of the country till then as well. So no worries there. 

I'll be anxious to hear about your testing results. But since ambient atmospheric pressure isn't 50% till 18K it really does need to be non-linear increase with altitude to get sufficient pressure at the start of the O2 needed altitudes like 12.5 and especially 14K. But you might also find it still works at a slightly lower O2 pressure too. Fingers crossed for you.

Looking forward to hearing what you learn.

[Rick Junkin]

Bottom Line Up Front (BLUF) - The Precise Flight X3 demand conserver will work with the early Scott/Avox altitude adjusting factory oxygen systems at oxygen altitudes based on inflight pressure measurements I made however Precise Flight has not tested them and therefore can’t recommend or ensure compatibility.

Details: The X3 requires a minimum delivery pressure of 22PSI and a maximum of 35PSI. I measured a delivery pressure of 8.5PSI on the ground at 1,000MSL and 23.5PSI at 12,500MSL in my Bravo with the Avox regulator part number 803216-03. So the altitude compensation works, and the delivery pressure at 12.5K exceeds the minimum required. An extrapolation to 25K using the non-linear atmospheric pressure lapse rate above 10K puts the delivery pressure right at the 35PSI maximum limit at 25K. 

I’ll provide more info on how they perform with the altitude compensating systems once I’ve used them for a while. I’ll be flying with my current flow metered cannulas on board as a backup until then.

Cheers,
Rick

[Fritz1]

I bought one for myself two years ago and I like it, bought another one for my wife just recently. I found that it works well for me when I run it 4000 ft over actual altitude during climb and keep it 2000 ft above in cruise. I use precise flight boom cannulas with phone ear bud pieces put over the nozzles, gives you more yield. I inhale through the nose and exhale through my mouth. The X3 reduces oxygen use by about 70%. I have a full size oxygen tank in my hangar on a big old cart. When that tank goes down to 1000 PSI I replace it. With a 115 cuft tank in the airplane I typically do a flight out to Montana from the east coast and back without buying any oxygen as long as I leave home with at least 1000 PSI.

[PJClark]

@Junkman

Greetings, sir.  I bought an X3 in January, expecting a bunch of business travel to Eglin AFB area this Spring and Summer and I want to get up high for the nonstop. (Also, a little sheepishly I just want to see my TAS up around 215+ at least once...)

I tested it on my way out to KSUS week before last, with the Mask on at FL180 (with 207 KTAS on about 71% power!). Kept me nicely oxygenated at 96-97% but I noticed my oxy quantity guage was dropping faster than normal, rather than slower, and after about 45 min of that I started investigating.  I discovered that the green Inline Regulator closest to the Scott fitting plugged into the Oxy port was constantly venting oxygen out both holes in the side.  So I descended to 16k and switched to my old A5 flowmeter and a cannula.

Is it possible I did something wrong? I will confess I may not have had it set up right.  I've just re-read the instructions and it's possible I had the switch in "Conserve" rather than "Constant"....would that have caused this?

I was afraid maybe my system is providing too much pressure and the Inline was therefore venting the excess.  @kortopates my airplane is an '86 252 so I think I can assume my system is the same as yours and Junkman's and ought to be compatible if I can figure out how to follow instructions???

thx Gents.

PJ

[Rick Junkin]

1 hour ago, PJClark said:

@Junkman

Greetings, sir.  I bought an X3 in January, expecting a bunch of business travel to Eglin AFB area this Spring and Summer and I want to get up high for the nonstop. (Also, a little sheepishly I just want to see my TAS up around 215+ at least once...)

I tested it on my way out to KSUS week before last, with the Mask on at FL180 (with 207 KTAS on about 71% power!). Kept me nicely oxygenated at 96-97% but I noticed my oxy quantity guage was dropping faster than normal, rather than slower, and after about 45 min of that I started investigating.  I discovered that the green Inline Regulator closest to the Scott fitting plugged into the Oxy port was constantly venting oxygen out both holes in the side.  So I descended to 16k and switched to my old A5 flowmeter and a cannula.

Is it possible I did something wrong? I will confess I may not have had it set up right.  I've just re-read the instructions and it's possible I had the switch in "Conserve" rather than "Constant"....would that have caused this?

I was afraid maybe my system is providing too much pressure and the Inline was therefore venting the excess.  @kortopates my airplane is an '86 252 so I think I can assume my system is the same as yours and Junkman's and ought to be compatible if I can figure out how to follow instructions???

thx Gents.

PJ

Hey @PJClark,

My X3 is working great for me. I used less than 100PSI on a round trip to Panama City Beach, about 4 hours of flight time at 15-16K using a cannula and the X3 on the "conserve" setting. I don't have an inline regulator installed. Based on the testing I did my O2 system output pressure stays under the maximum limit for the X3 so the inline regulator wouldn't be required.

You might try removing the inline regulator and see how it works for you. But first it might be prudent to take the same kind of measurements I did to ensure your O2 system isn't really putting out more pressure than the X3 can handle. If your airplane has a factory altitude compensating regulator on the tank then you are probably ok. But there are a number of regulator configs so you want to be sure. I measured a delivery pressure of 8.5PSI on the ground at 1,000' PA so if you can duplicate that you may not need to repeat the airborne tests I did.

I had kind of a Rube Goldberg set-up to test the delivered O2 pressure. I didn't have a pneumatic pressure gauge handy but I had one of these:

I connected a length of O2 tubing to right seat Oxygen port and connected the other end of the tubing to the pump using an inflator nozzle attachment that fit snugly into the tubing. I turned the pump display power on at the check altitudes to take the pressure readings. Worked great, as would any other pump that displays the "tire" pressure without the compressor running. Of course if you have a pneumatic pressure gauge connected to the length of tubing, that would be optimum and provide a continuous reading for your observations.

Give me a call if you want to chat, I think you have my number.

Cheers,
Rick