TLS factory oxygen system - connector

[tectweaker]

I recently bought a tls bravo and have been trying to figure out a oxygen issue.

 

The hydro on the bottle is current and all inspections are good. Without turning any valves - it does not leak.

if I open the cockpit valve and don’t connect any cannulas - it does not leak and holds pressure well.

 

howver, when I use a Oxymizer Cannula from Aerox - it is going down pressure very quickly - about 30-40 psi every 5 mins.

 

i noticed that there was a a thread on the forum talking about using particular kinds of connectors with the factory oxygen system. I believe that precise flight was the right one per that thread.

 

i just wanted to confirm that I should order precise flights Scott connectors are the right ones?

 

it is confusing because the Scott is all supposed to be the same connector. The Aerox Scott cannula that I have was just bought new recently.

 

if there is no difference then I will look in the low pressure line carefully again. Perhaps it is not the connector and something else - I have not found any obvious leaks yet.

Edited December 23, 2018 by tectweaker
Fixed typo

[DonMuncy]

At 40 psi every 15 minutes, that is 120 and hour. Presuming you start with 1800, that would be 15 hours. That is very small amount of O2 to use. If that was a typo, and you are losing 300 to 400 in 15 minutes, that is a very different situation. 

I recognize that usage is in cu ft, and that doesn't relate linearly with psi.

[tectweaker]

Yes typo there. It is about 40 psi every 5 min. And that is with just one cannula connected.

[Rick Junkin]

20 minutes ago, tectweaker said:

howver, when I use a Oxymizer Cannula from Aerox - it is going down pressure very quickly - about 30-40 psi every 15 mins.

 

What altitude are you operating at? And what is the indicated pressure in your tank?

Looking at the chart in the POH and using numbers that make the math easy, if you had 1200psi in the tank and were flying at 15,000 feet, you would have 20.4 hours of oxygen using the "normal" delivery system, and would expect twice that with an oxymizer. That's a lot more than the 10 hours you would get at you current consumption rate. Something seems amiss.

Having said that, I don't get the book numbers in my TLS either. I don't know exactly what I'm getting, but your numbers work out close to mine I think. I' see if I can calculate a guesstimate and get back to you.

Cheers,
Rick

 

[carusoam]

If you can’t get the expected answer...

Look into the everlasting challenge of having the right connectors... matching brand for brand...

I believe one supplier diameter is slightly different than the other.... but, you can tell them apart by the length..?

Got a pic of the two different connectors you have? (Somebody might recognize what you are seeing)

 

This is probably a challenge the first time a Mooney pilot buys some O2 equipment...

There is probably a thread around here as well...

This is K specific, but may give some insight to what other people have run into...

Best regards,

-a-

 

[Rick Junkin]

1 hour ago, tectweaker said:

Yes typo there. It is about 40 psi every 5 min. And that is with just one cannula connected.

Something seems not quite right there. 

I use the Precise Flight equipment: green Scott connectors, A5 flow meters, and Precise Flight boom cannulas (not saver-type cannulas) that attach to our headsets. We went from about 1600psi to 650psi in the course of about 7 hours at altitude (15,000 feet) with two people on our last trip. As Don mentioned, PSI consumption rate is not linear so may be a bit misleading. However my O2 time duration numbers do look to match the book pretty closely when I work through the chart. How much more O2 are you using, measured in time/duration, in relation to what the chart tells you that you should be using? Stated another way, how much duration does the chart say you should get from the pressure differential you consumed? That may be a better starting point for you in determining the magnitude of the problem, which might then eliminate some potential causes from consideration.

Cheers,
Rick

[tectweaker]

It is clear that there is some sort of a leak etc per the chart. At the current pace the oxygen utilization is 4-5 times higher then in the chart.

 

The real question is if precise flight connectors are the only compatible connectors with Mooney factory oxygen system? It seems like everybody has those here. Otherwise, I will continue diagnosing.

 

I happen to not have them and will need to order them. If anybody has a connector or two in San Jose area - would love to see if I can try them before I order them.

[rpcc]

this looks like it may help you.  https://preciseflight.s3.amazonaws.com/doc/106NMAN0001A.pdf?Signature=aQL1SUvpp0g0jBA3b0G8pTlG82A%3D&Expires=1545589047&AWSAccessKeyId=AKIAIQJHHF2UOD3ZQP7Q

[Awful_Charlie]

I use Scott green connectors with a flowmeter and oxysaver cannualas or masks, and occasionally red connectors with oxysaver cannulas and no flowmeter (for kids who might otherwise fiddle)

I reckon on getting about double the book duration using oxysavers (would of course be an extra 1/3rd if everyone was on reds)

If your flows are so high, have you checked the output from the altitude compensating regulator pressure? Maybe is is going (substantially!) overpressure?

Edited December 23, 2018 by Awful_Charlie

[larryb]

If you get the mountain high O2D2 your built in oxygen tank will last a whole year of flying. You will never ever have to fill on a trip.

[ilovecornfields]

4 hours ago, larryb said:

If you get the mountain high O2D2 your built in oxygen tank will last a whole year of flying. You will never ever have to fill on a trip.

That’s an exaggeration! Mine only lasts 9 months on a single fill.

[Awful_Charlie]

22 hours ago, larryb said:

If you get the mountain high O2D2 your built in oxygen tank will last a whole year of flying. You will never ever have to fill on a trip.

I thought about one of these, but it's another thing to go wrong, adds to the rubber overhead jungle, and the price of one unit buys 10 years of oxygen!

[larryb]

It can be cleanly installed. All tubes are behind the panel and side interior panels. It also beeps at you if you don’t breath properly or a hose comes disconnected. You know if you are not getting O2 delivery.

 

 

 

 

[gsxrpilot]

I have mine mounted in the same place. All hoses routed behind panels. It's a very clean install that doesn't get in the way of anything. I included a way to tuck the hose up under the panel if I want to remove the unit. There are time I know I won't be using O2 for several flights and so I can put it away and hide the hoses.

As @larryb said, the built in alarms are an added safety factor for me when I'm in the flight levels above 20K ft. 

 

[exM20K]

My Acclaim has the outlets overhead center, so it is a bit of a mess.  However, I find the O2D2 to be worthwhile not only for its efficiency, but also because it cures the constant, drying flow of O2.  PAX love it.  My biggest concern is keeping hoses clear of the trim wheel.

 

For the OP, I’d investigate the pressure regulator or borrow a MH system with the reducer on it to maybe isolate the leak source. 

[FloridaMan]

This may be a stupid question, but you do have one of those regulators with the needle valve and floating ball inline with your cannula, right? I typically would use around 500psi over 3 hours prior to getting an O2D2 which gets about 5-10x as much duration.