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Nitrogen Loss
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skyking76t(at)verizon.net
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PostPosted: Wed Mar 23, 2016 9:26 am    Post subject: Nitrogen Loss Reply with quote

Guys, my L-29 has always held nitrogen for days without much loss of pressure. Other day I pressurized to 140 atm because of a long flight and day. Pressure bled off immediately from 140 to about 90 atm before I could get out of the hangar. And was totally empty the next day. I found several loose, original safety wired, connections not tight. Packing nut on the nitrogen purge valve was loose too. Tightened every fitting and thing I could find from nose to rear cockpit.
Now, if I pressurize to 50 atm, I will lose 30 atm in 12 hours. If I pressurize to 100 atm I lose 30 atm in 12 hours. Very consistent now. That's about 2.5 atm per hour. Any suggestions what else might cause such a consistent leak? Thinking maybe the pressure relief valve leaking? Check valve? Reading manuals and reviewing diagrams but thought maybe someone else may have run into this same problem and save a lot of time
Someone, in a post I can't find, suggested an ultrasonic tester of some sort to detect high pressure leaks. Does anyone know which one it was?
Also, looking for the glass lens for the taxi light. Rock must have hit mineand cracked it in half. Glued it back but would like to replacement. Also looking for connector to ARC EA-401A encoding altimeter.
Thanks for any info
Anthony


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tr.9(at)westnet.com.au
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PostPosted: Wed Mar 23, 2016 5:19 pm    Post subject: Nitrogen Loss Reply with quote

Anthony,
The post about the ultra sonic tester was, I think, originally to do with the thread about the electric air pump system installed in the nose section and used to pump up the pneumatic system as required. I think the jet was/is based in Sweden or Norway? FWIW I think I saw recently that jet is now for sale too?
Cheers,
Frank

Sent from my iPad

On Mar 24, 2016, at 2:22 AM, Anthony Royal <skyking76t(at)verizon.net (skyking76t(at)verizon.net)> wrote:
Quote:
Guys, my L-29 has always held nitrogen for days without much loss of pressure. Other day I pressurized to 140 atm because of a long flight and day. Pressure bled off immediately from 140 to about 90 atm before I could get out of the hangar. And was totally empty the next day. I found several loose, original safety wired, connections not tight. Packing nut on the nitrogen purge valve was loose too. Tightened every fitting and thing I could find from nose to rear cockpit.
Now, if I pressurize to 50 atm, I will lose 30 atm in 12 hours. If I pressurize to 100 atm I lose 30 atm in 12 hours. Very consistent now. That's about 2.5 atm per hour. Any suggestions what else might cause such a consistent leak? Thinking maybe the pressure relief valve leaking? Check valve? Reading manuals and reviewing diagrams but thought maybe someone else may have run into this same problem and save a lot of time
Someone, in a post I can't find, suggested an ultrasonic tester of some sort to detect high pressure leaks. Does anyone know which one it was?
Also, looking for the glass lens for the taxi light. Rock must have hit mineand cracked it in half. Glued it back but would like to replacement. Also looking for connector to ARC EA-401A encoding altimeter.
Thanks for any info
Anthony


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Dawg



Joined: 19 May 2013
Posts: 355

PostPosted: Wed Mar 23, 2016 5:22 pm    Post subject: Nitrogen Loss Reply with quote

Remove the front seat and the floor boards to the left of the stick and the stick boot. 2 Brake valves on the left. Check the lower onethat is hardest to get to. 19mm. good luck. need a small, bent, twisted wrench.

On Mar 23, 2016, at 9:22, Anthony Royal <skyking76t(at)verizon.net (skyking76t(at)verizon.net)> wrote:
Quote:
Guys, my L-29 has always held nitrogen for days without much loss of pressure. Other day I pressurized to 140 atm because of a long flight and day. Pressure bled off immediately from 140 to about 90 atm before I could get out of the hangar. And was totally empty the next day. I found several loose, original safety wired, connections not tight. Packing nut on the nitrogen purge valve was loose too. Tightened every fitting and thing I could find from nose to rear cockpit.
Now, if I pressurize to 50 atm, I will lose 30 atm in 12 hours. If I pressurize to 100 atm I lose 30 atm in 12 hours. Very consistent now. That's about 2.5 atm per hour. Any suggestions what else might cause such a consistent leak? Thinking maybe the pressure relief valve leaking? Check valve? Reading manuals and reviewing diagrams but thought maybe someone else may have run into this same problem and save a lot of time
Someone, in a post I can't find, suggested an ultrasonic tester of some sort to detect high pressure leaks. Does anyone know which one it was?
Also, looking for the glass lens for the taxi light. Rock must have hit mineand cracked it in half. Glued it back but would like to replacement. Also looking for connector to ARC EA-401A encoding altimeter.
Thanks for any info
Anthony



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bculberson(at)staraviatio
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PostPosted: Wed Mar 23, 2016 7:19 pm    Post subject: Nitrogen Loss Reply with quote

The valve Bill is talking about is the one I had a problem with. Find a small guy that's good with tools. In my case, fitting was loose...tightened and all was well.


Bill
N39DE






Sent from my T-Mobile 4G LTE Device





-------- Original message --------
From: Bill Geipel <l129bs(at)gmail.com>
Date: 3/23/2016 9:27 PM (GMT-05:00)
To: L29list <l29-list(at)matronics.com>
Subject: Re: Nitrogen Loss


Remove the front seat and the floor boards to the left of the stick and the stick boot. 2 Brake valves on the left. Check the lower one that is hardest to get to. 19mm. good luck. need a small, bent, twisted wrench.



On Mar 23, 2016, at 9:22, Anthony Royal <skyking76t(at)verizon.net (skyking76t(at)verizon.net)> wrote:
Quote:
Guys, my L-29 has always held nitrogen for days without much loss of pressure. Other day I pressurized to 140 atm because of a long flight and day. Pressure bled off immediately from 140 to about 90 atm before I could get out of the hangar. And was totally empty the next day. I found several loose, original safety wired, connections not tight. Packing nut on the nitrogen purge valve was loose too. Tightened every fitting and thing I could find from nose to rear cockpit.


Now, if I pressurize to 50 atm, I will lose 30 atm in 12 hours. If I pressurize to 100 atm I lose 30 atm in 12 hours. Very consistent now. That's about 2.5 atm per hour. Any suggestions what else might cause such a consistent leak? Thinking maybe the pressure relief valve leaking? Check valve? Reading manuals and reviewing diagrams but thought maybe someone else may have run into this same problem and save a lot of time


Someone, in a post I can't find, suggested an ultrasonic tester of some sort to detect high pressure leaks. Does anyone know which one it was?


Also, looking for the glass lens for the taxi light. Rock must have hit mineand cracked it in half. Glued it back but would like to replacement. Also looking for connector to ARC EA-401A encoding altimeter.


Thanks for any info


Anthony



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jetblast1(at)me.com
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PostPosted: Thu Mar 24, 2016 3:12 pm    Post subject: Nitrogen Loss Reply with quote

I don”t know if this is going to be of any help and some may laugh at me but i was chasing at leak in the rear canopy. Bought a fancy ultrasonic leak detector and could not find any leak. Finally decided to check with old fashion soapy water and a spray bottle. That worked.
John
Quote:
On Mar 23, 2016, at 8:22 AM, Anthony Royal <skyking76t(at)verizon.net (skyking76t(at)verizon.net)> wrote:
Guys, my L-29 has always held nitrogen for days without much loss of pressure. Other day I pressurized to 140 atm because of a long flight and day. Pressure bled off immediately from 140 to about 90 atm before I could get out of the hangar. And was totally empty the next day. I found several loose, original safety wired, connections not tight. Packing nut on the nitrogen purge valve was loose too. Tightened every fitting and thing I could find from nose to rear cockpit.

Now, if I pressurize to 50 atm, I will lose 30 atm in 12 hours. If I pressurize to 100 atm I lose 30 atm in 12 hours. Very consistent now. That's about 2.5 atm per hour. Any suggestions what else might cause such a consistent leak? Thinking maybe the pressure relief valve leaking? Check valve? Reading manuals and reviewing diagrams but thought maybe someone else may have run into this same problem and save a lot of time

Someone, in a post I can't find, suggested an ultrasonic tester of some sort to detect high pressure leaks. Does anyone know which one it was?

Also, looking for the glass lens for the taxi light. Rock must have hit mineand cracked it in half. Glued it back but would like to replacement. Also looking for connector to ARC EA-401A encoding altimeter.

Thanks for any info

Anthony



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skyking76t(at)verizon.net
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PostPosted: Thu Mar 24, 2016 4:20 pm    Post subject: Nitrogen Loss Reply with quote

Hey guys,
Thanks for all your suggestions! John, I did the soapy water test on every fitting I could find all the way back to the fittings for the emergency bottle and beyond. ...tightened too. No Joy.
Bill, I think I did the top nut but missed the lower nut. I'll look at that next . Yeah, I'm 60 and a little too big to get into that small of quarters.
Hey Frank, thanks for the info too!
I'm also looking at disconnecting the the main pressurizing line line at the pressure reduction valve for the down stream items, after the nitrogen bottles, and capping off the line and then pressurizing the bottles. This should tell me if there is a leak anywhere upstream of the reduction valve in the main charging system. The emergency bottle holds pressure perfectly so no problems there.
According to the service manual, the minimum loss is 5 atm over 2 hours. So, I'm right on that limit at 2.5 atm per hour.
Thanks!
Tony

On Thursday, March 24, 2016 7:15 PM, John Cabrera <jetblast1(at)me.com> wrote:



I don”t know if this is going to be of any help and some may laugh at me but i was chasing at leak in the rear canopy. Bought a fancy ultrasonic leak detector and could not find any leak. Finally decided to check with old fashion soapy water and a spray bottle. That worked.
John
Quote:
On Mar 23, 2016, at 8:22 AM, Anthony Royal <skyking76t(at)verizon.net (skyking76t(at)verizon.net)> wrote:
Guys, my L-29 has always held nitrogen for days without much loss of pressure. Other day I pressurized to 140 atm because of a long flight and day. Pressure bled off immediately from 140 to about 90 atm before I could get out of the hangar. And was totally empty the next day. I found several loose, original safety wired, connections not tight. Packing nut on the nitrogen purge valve was loose too. Tightened every fitting and thing I could find from nose to rear cockpit.

Now, if I pressurize to 50 atm, I will lose 30 atm in 12 hours. If I pressurize to 100 atm I lose 30 atm in 12 hours. Very consistent now. That's about 2.5 atm per hour. Any suggestions what else might cause such a consistent leak? Thinking maybe the pressure relief valve leaking? Check valve? Reading manuals and reviewing diagrams but thought maybe someone else may have run into this same problem and save a lot of time

Someone, in a post I can't find, suggested an ultrasonic tester of some sort to detect high pressure leaks. Does anyone know which one it was?

Also, looking for the glass lens for the taxi light. Rock must have hit mineand cracked it in half. Glued it back but would like to replacement. Also looking for connector to ARC EA-401A encoding altimeter.

Thanks for any info

Anthony



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jorgen.nielsen(at)mweb.co
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PostPosted: Thu Mar 24, 2016 11:53 pm    Post subject: Nitrogen Loss Reply with quote

I also tried an ultrasonic leak detector, got a very expensive version on trial for a week from a specialty supplier.  Could not find anything using it either.  Soapy water is messy but seems to work best.

My air system is modified, with a hand valve installed close to the bottles.  When I am done flying, I shut it off.  Also nice if using the L29 to go somewhere, turn it off after landing, turn it back on before flight, no losses.

From: owner-l29-list-server(at)matronics.com [mailto:owner-l29-list-server(at)matronics.com] On Behalf Of Anthony Royal
Sent: Friday, 25 March 2016 02:17
To: l29-list(at)matronics.com
Subject: Re: Nitrogen Loss

Hey guys,

Thanks for all your suggestions! John, I did the soapy water test on every fitting I could find all the way back to the fittings for the emergency bottle and beyond. ...tightened too. No Joy.



Bill, I think I did the top nut but missed the lower nut. I'll look at that next . Yeah, I'm 60 and a little too big to get into that small of quarters.



Hey Frank, thanks for the info too!



I'm also looking at disconnecting the the main pressurizing line line at the pressure reduction valve for the down stream items, after the nitrogen bottles, and capping off the line and then pressurizing the bottles. This should tell me if there is a leak anywhere upstream of the reduction valve in the main charging system. The emergency bottle holds pressure perfectly so no problems there.



According to the service manual, the minimum loss is 5 atm over 2 hours. So, I'm right on that limit at 2.5 atm per hour.



Thanks!

Tony









On Thursday, March 24, 2016 7:15 PM, John Cabrera <jetblast1(at)me.com (jetblast1(at)me.com)> wrote:


I don”t know if this is going to be of any help and some may laugh at me but i was chasing at leak in the rear canopy. Bought a fancy ultrasonic leak detector and could not find any leak. Finally decided to check with old fashion soapy water and a spray bottle. That worked.


John





Quote:

On Mar 23, 2016, at 8:22 AM, Anthony Royal <skyking76t(at)verizon.net (skyking76t(at)verizon.net)> wrote:


Guys, my L-29 has always held nitrogen for days without much loss of pressure. Other day I pressurized to 140 atm because of a long flight and day. Pressure bled off immediately from 140 to about 90 atm before I could get out of the hangar. And was totally empty the next day. I found several loose, original safety wired, connections not tight. Packing nut on the nitrogen purge valve was loose too. Tightened every fitting and thing I could find from nose to rear cockpit.



Now, if I pressurize to 50 atm, I will lose 30 atm in 12 hours. If I pressurize to 100 atm I lose 30 atm in 12 hours. Very consistent now. That's about 2.5 atm per hour. Any suggestions what else might cause such a consistent leak? Thinking maybe the pressure relief valve leaking? Check valve? Reading manuals and reviewing diagrams but thought maybe someone else may have run into this same problem and save a lot of time



Someone, in a post I can't find, suggested an ultrasonic tester of some sort to detect high pressure leaks. Does anyone know which one it was?



Also, looking for the glass lens for the taxi light. Rock must have hit mineand cracked it in half. Glued it back but would like to replacement. Also looking for connector to ARC EA-401A encoding altimeter.



Thanks for any info



Anthony



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bculberson(at)staraviatio
Guest





PostPosted: Fri Mar 25, 2016 9:19 am    Post subject: Nitrogen Loss Reply with quote

Ultrasonic leak detector only works on the high pressure leaks (75-100 BAR), as it detects the specific audio signature of high pressure gas escaping. Canopy seals and brakes are at lower pressures and the soap and water test seems best.

I don’t use a Schrader valve but rather the original quarter turn valve but recently converted the N2 Cover to having a Schrader adapter “just in case”. My plane doesn’t leak much but discovered that with the cover changed and a good gasket the N2 cover that the N2 remains for weeks instead of days. Main check valve must be leaking.

I like the Hand valve at the tanks, what did you use? Pics?

Bill
N39DE

From: owner-l29-list-server(at)matronics.com [mailto:owner-l29-list-server(at)matronics.com] On Behalf Of Jorgen Nielsen
Sent: Friday, March 25, 2016 2:52 AM
To: l29-list(at)matronics.com
Subject: RE: L29-List: Nitrogen Loss

I also tried an ultrasonic leak detector, got a very expensive version on trial for a week from a specialty supplier. Could not find anything using it either. Soapy water is messy but seems to work best.

My air system is modified, with a hand valve installed close to the bottles. When I am done flying, I shut it off. Also nice if using the L29 to go somewhere, turn it off after landing, turn it back on before flight, no losses.

From: owner-l29-list-server(at)matronics.com (owner-l29-list-server(at)matronics.com) [mailto:owner-l29-list-server(at)matronics.com (owner-l29-list-server(at)matronics.com)] On Behalf Of Anthony Royal
Sent: Friday, 25 March 2016 02:17
To: l29-list(at)matronics.com (l29-list(at)matronics.com)
Subject: Re: L29-List: Nitrogen Loss

Hey guys,

Thanks for all your suggestions! John, I did the soapy water test on every fitting I could find all the way back to the fittings for the emergency bottle and beyond. ...tightened too. No Joy.



Bill, I think I did the top nut but missed the lower nut. I'll look at that next . Yeah, I'm 60 and a little too big to get into that small of quarters.



Hey Frank, thanks for the info too!



I'm also looking at disconnecting the the main pressurizing line line at the pressure reduction valve for the down stream items, after the nitrogen bottles, and capping off the line and then pressurizing the bottles. This should tell me if there is a leak anywhere upstream of the reduction valve in the main charging system. The emergency bottle holds pressure perfectly so no problems there.



According to the service manual, the minimum loss is 5 atm over 2 hours. So, I'm right on that limit at 2.5 atm per hour.



Thanks!

Tony









On Thursday, March 24, 2016 7:15 PM, John Cabrera <jetblast1(at)me.com (jetblast1(at)me.com)> wrote:


I don”t know if this is going to be of any help and some may laugh at me but i was chasing at leak in the rear canopy. Bought a fancy ultrasonic leak detector and could not find any leak. Finally decided to check with old fashion soapy water and a spray bottle. That worked.


John





Quote:

On Mar 23, 2016, at 8:22 AM, Anthony Royal <skyking76t(at)verizon.net (skyking76t(at)verizon.net)> wrote:


Guys, my L-29 has always held nitrogen for days without much loss of pressure. Other day I pressurized to 140 atm because of a long flight and day. Pressure bled off immediately from 140 to about 90 atm before I could get out of the hangar. And was totally empty the next day. I found several loose, original safety wired, connections not tight. Packing nut on the nitrogen purge valve was loose too. Tightened every fitting and thing I could find from nose to rear cockpit.



Now, if I pressurize to 50 atm, I will lose 30 atm in 12 hours. If I pressurize to 100 atm I lose 30 atm in 12 hours. Very consistent now. That's about 2.5 atm per hour. Any suggestions what else might cause such a consistent leak? Thinking maybe the pressure relief valve leaking? Check valve? Reading manuals and reviewing diagrams but thought maybe someone else may have run into this same problem and save a lot of time



Someone, in a post I can't find, suggested an ultrasonic tester of some sort to detect high pressure leaks. Does anyone know which one it was?



Also, looking for the glass lens for the taxi light. Rock must have hit mineand cracked it in half. Glued it back but would like to replacement. Also looking for connector to ARC EA-401A encoding altimeter.



Thanks for any info



Anthony








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Back to top
tr.9(at)westnet.com.au
Guest





PostPosted: Fri Mar 25, 2016 11:07 am    Post subject: Nitrogen Loss Reply with quote

I read once about an L-29 being operated in the UK where they disconnected the oxy system and plumbed those bottles into the pneumatic system, almost doubles the capacity if I recall...? Has anyone else looked at doing that?
Frank

Sent from my iPad

On Mar 26, 2016, at 4:20 AM, Bill Culberson <bculberson(at)staraviation.com (bculberson(at)staraviation.com)> wrote:
Quote:
<![endif]--> <![endif]-->
Ultrasonic leak detector only works on the high pressure leaks (75-100 BAR), as it detects the specific audio signature of high pressure gas escaping. Canopy seals and brakes are at lower pressures and the soap and water test seems best.

I don’t use a Schrader valve but rather the original quarter turn valve but recently converted the N2 Cover to having a Schrader adapter “just in case”. My plane doesn’t leak much but discovered that with the cover changed and a good gasket the N2 cover that the N2 remains for weeks instead of days. Main check valve must be leaking.

I like the Hand valve at the tanks, what did you use? Pics?

Bill
N39DE

From: owner-l29-list-server(at)matronics.com (owner-l29-list-server(at)matronics.com) [mailto:owner-l29-list-server(at)matronics.com (owner-l29-list-server(at)matronics.com)] On Behalf Of Jorgen Nielsen
Sent: Friday, March 25, 2016 2:52 AM
To: l29-list(at)matronics.com (l29-list(at)matronics.com)
Subject: RE: Nitrogen Loss

I also tried an ultrasonic leak detector, got a very expensive version on trial for a week from a specialty supplier. Could not find anything using it either. Soapy water is messy but seems to work best.

My air system is modified, with a hand valve installed close to the bottles. When I am done flying, I shut it off. Also nice if using the L29 to go somewhere, turn it off after landing, turn it back on before flight, no losses.

From: owner-l29-list-server(at)matronics.com (owner-l29-list-server(at)matronics.com) [mailto:owner-l29-list-server(at)matronics.com (owner-l29-list-server(at)matronics.com)] On Behalf Of Anthony Royal
Sent: Friday, 25 March 2016 02:17
To: l29-list(at)matronics.com (l29-list(at)matronics.com)
Subject: Re: Nitrogen Loss

Hey guys,

Thanks for all your suggestions! John, I did the soapy water test on every fitting I could find all the way back to the fittings for the emergency bottle and beyond. ...tightened too. No Joy.



Bill, I think I did the top nut but missed the lower nut. I'll look at that next . Yeah, I'm 60 and a little too big to get into that small of quarters.



Hey Frank, thanks for the info too!



I'm also looking at disconnecting the the main pressurizing line line at the pressure reduction valve for the down stream items, after the nitrogen bottles, and capping off the line and then pressurizing the bottles. This should tell me if there is a leak anywhere upstream of the reduction valve in the main charging system. The emergency bottle holds pressure perfectly so no problems there.



According to the service manual, the minimum loss is 5 atm over 2 hours. So, I'm right on that limit at 2.5 atm per hour.



Thanks!

Tony









On Thursday, March 24, 2016 7:15 PM, John Cabrera <jetblast1(at)me.com (jetblast1(at)me.com)> wrote:


I don”t know if this is going to be of any help and some may laugh at me but i was chasing at leak in the rear canopy. Bought a fancy ultrasonic leak detector and could not find any leak. Finally decided to check with old fashion soapy water and a spray bottle. That worked.


John





Quote:

On Mar 23, 2016, at 8:22 AM, Anthony Royal <skyking76t(at)verizon.net (skyking76t(at)verizon.net)> wrote:


Guys, my L-29 has always held nitrogen for days without much loss of pressure. Other day I pressurized to 140 atm because of a long flight and day. Pressure bled off immediately from 140 to about 90 atm before I could get out of the hangar. And was totally empty the next day. I found several loose, original safety wired, connections not tight. Packing nut on the nitrogen purge valve was loose too. Tightened every fitting and thing I could find from nose to rear cockpit.



Now, if I pressurize to 50 atm, I will lose 30 atm in 12 hours. If I pressurize to 100 atm I lose 30 atm in 12 hours. Very consistent now. That's about 2.5 atm per hour. Any suggestions what else might cause such a consistent leak? Thinking maybe the pressure relief valve leaking? Check valve? Reading manuals and reviewing diagrams but thought maybe someone else may have run into this same problem and save a lot of time



Someone, in a post I can't find, suggested an ultrasonic tester of some sort to detect high pressure leaks. Does anyone know which one it was?



Also, looking for the glass lens for the taxi light. Rock must have hit mineand cracked it in half. Glued it back but would like to replacement. Also looking for connector to ARC EA-401A encoding altimeter.



Thanks for any info



Anthony









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jorgen.nielsen(at)mweb.co
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PostPosted: Fri Mar 25, 2016 11:51 am    Post subject: Nitrogen Loss Reply with quote

Mine is also done like that.  I only posted half the story earlier, herewith then the full story J

I don’t use oxygen, so repurposed the tanks. 

My oxygen tanks have a tap on them, close to the bottles, and a pressure gauge.  The tap & gauge is situated in the nose compartment.
My normal air bottle (N2) also have a tap on them, and a gauge, also in the nose compartment. 
So far, 2 separate systems.
After the taps, they are interconnected via a T, output goes to the air system.

Benefits:
Closing the valves means no leaks when she is standing.
Having the 2 systems that close means I can go away for a weekend with no ground support, or for example a 3 hop ferry I did a while back.  At the destination, close the active system.  For the next flight, pick a system and open valve.  When the system is empty use the next one.

To fill, if its just a normal flight from home base, I open the valve for whichever system is in use, and fill normally.  For extended flights, one can fill one system at a time, or open both and fill both, then close one.

So far, completely trouble free for a number of years.

I will have to take some pics when at the airport.  I used spare hand operated valves, similar to the pressure release inside the cockpit.  I never did the work myself, I have a Russian guy who does all my maintenance, I just dreamt it up and asked him to do it.

Another mod we did:  my front / rear braking system has been reversed.  I was once taxying with pax, and asked them to hold the brake while I did something.  On release, when I took over, suddenly I had no brakes, and no steering obviously.  We almost went farming.  In normal ops, the rear brake is for the instructor, and held a certain way can disable the front cabin system.  Not good for how we operate them privately.    

Regards to all
Jorgen

From: owner-l29-list-server(at)matronics.com [mailto:owner-l29-list-server(at)matronics.com] On Behalf Of Frank Deeth
Sent: Friday, 25 March 2016 21:07
To: l29-list(at)matronics.com
Subject: Re: Nitrogen Loss

I read once about an L-29 being operated in the UK where they disconnected the oxy system and plumbed those bottles into the pneumatic system, almost doubles the capacity if I recall...? Has anyone else looked at doing that?



Frank

Sent from my iPad
On Mar 26, 2016, at 4:20 AM, Bill Culberson <bculberson(at)staraviation.com (bculberson(at)staraviation.com)> wrote:
Quote:

Ultrasonic leak detector only works on the high pressure leaks (75-100 BAR), as it detects the specific audio signature of high pressure gas escaping. Canopy seals and brakes are at lower pressures and the soap and water test seems best.

I don’t use a Schrader valve but rather the original quarter turn valve but recently converted the N2 Cover to having a Schrader adapter “just in case”. My plane doesn’t leak much but discovered that with the cover changed and a good gasket the N2 cover that the N2 remains for weeks instead of days. Main check valve must be leaking.

I like the Hand valve at the tanks, what did you use? Pics?

Bill
N39DE

From: owner-l29-list-server(at)matronics.com (owner-l29-list-server(at)matronics.com) [mailto:owner-l29-list-server(at)matronics.com (owner-l29-list-server(at)matronics.com)] On Behalf Of Jorgen Nielsen
Sent: Friday, March 25, 2016 2:52 AM
To: l29-list(at)matronics.com (l29-list(at)matronics.com)
Subject: RE: Nitrogen Loss

I also tried an ultrasonic leak detector, got a very expensive version on trial for a week from a specialty supplier. Could not find anything using it either. Soapy water is messy but seems to work best.

My air system is modified, with a hand valve installed close to the bottles. When I am done flying, I shut it off. Also nice if using the L29 to go somewhere, turn it off after landing, turn it back on before flight, no losses.

From: owner-l29-list-server(at)matronics.com (owner-l29-list-server(at)matronics.com) [mailto:owner-l29-list-server(at)matronics.com (owner-l29-list-server(at)matronics.com)] On Behalf Of Anthony Royal
Sent: Friday, 25 March 2016 02:17
To: l29-list(at)matronics.com (l29-list(at)matronics.com)
Subject: Re: Nitrogen Loss

Hey guys,

Thanks for all your suggestions! John, I did the soapy water test on every fitting I could find all the way back to the fittings for the emergency bottle and beyond. ...tightened too. No Joy.



Bill, I think I did the top nut but missed the lower nut. I'll look at that next . Yeah, I'm 60 and a little too big to get into that small of quarters.



Hey Frank, thanks for the info too!



I'm also looking at disconnecting the the main pressurizing line line at the pressure reduction valve for the down stream items, after the nitrogen bottles, and capping off the line and then pressurizing the bottles. This should tell me if there is a leak anywhere upstream of the reduction valve in the main charging system. The emergency bottle holds pressure perfectly so no problems there.



According to the service manual, the minimum loss is 5 atm over 2 hours. So, I'm right on that limit at 2.5 atm per hour.



Thanks!

Tony









On Thursday, March 24, 2016 7:15 PM, John Cabrera <jetblast1(at)me.com (jetblast1(at)me.com)> wrote:


I don”t know if this is going to be of any help and some may laugh at me but i was chasing at leak in the rear canopy. Bought a fancy ultrasonic leak detector and could not find any leak. Finally decided to check with old fashion soapy water and a spray bottle. That worked.


John





Quote:

On Mar 23, 2016, at 8:22 AM, Anthony Royal <skyking76t(at)verizon.net (skyking76t(at)verizon.net)> wrote:


Guys, my L-29 has always held nitrogen for days without much loss of pressure. Other day I pressurized to 140 atm because of a long flight and day. Pressure bled off immediately from 140 to about 90 atm before I could get out of the hangar. And was totally empty the next day. I found several loose, original safety wired, connections not tight. Packing nut on the nitrogen purge valve was loose too. Tightened every fitting and thing I could find from nose to rear cockpit.



Now, if I pressurize to 50 atm, I will lose 30 atm in 12 hours. If I pressurize to 100 atm I lose 30 atm in 12 hours. Very consistent now. That's about 2.5 atm per hour. Any suggestions what else might cause such a consistent leak? Thinking maybe the pressure relief valve leaking? Check valve? Reading manuals and reviewing diagrams but thought maybe someone else may have run into this same problem and save a lot of time



Someone, in a post I can't find, suggested an ultrasonic tester of some sort to detect high pressure leaks. Does anyone know which one it was?



Also, looking for the glass lens for the taxi light. Rock must have hit mineand cracked it in half. Glued it back but would like to replacement. Also looking for connector to ARC EA-401A encoding altimeter.



Thanks for any info



Anthony










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Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:

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Back to top
tr.9(at)westnet.com.au
Guest





PostPosted: Fri Mar 25, 2016 11:59 am    Post subject: Nitrogen Loss Reply with quote

Thanks Jorgen!

Sent from my iPhone

On 26 Mar 2016, at 6:50 AM, Jorgen Nielsen <jorgen.nielsen(at)mweb.co.za (jorgen.nielsen(at)mweb.co.za)> wrote:
Quote:
<![endif]--> <![endif]-->
Mine is also done like that. I only posted half the story earlier, herewith then the full story J

I don’t use oxygen, so repurposed the tanks.

My oxygen tanks have a tap on them, close to the bottles, and a pressure gauge. The tap & gauge is situated in the nose compartment.
My normal air bottle (N2) also have a tap on them, and a gauge, also in the nose compartment.
So far, 2 separate systems.
After the taps, they are interconnected via a T, output goes to the air system.

Benefits:
Closing the valves means no leaks when she is standing.
Having the 2 systems that close means I can go away for a weekend with no ground support, or for example a 3 hop ferry I did a while back. At the destination, close the active system. For the next flight, pick a system and open valve. When the system is empty use the next one.

To fill, if its just a normal flight from home base, I open the valve for whichever system is in use, and fill normally. For extended flights, one can fill one system at a time, or open both and fill both, then close one.

So far, completely trouble free for a number of years.

I will have to take some pics when at the airport. I used spare hand operated valves, similar to the pressure release inside the cockpit. I never did the work myself, I have a Russian guy who does all my maintenance, I just dreamt it up and asked him to do it.

Another mod we did: my front / rear braking system has been reversed. I was once taxying with pax, and asked them to hold the brake while I did something. On release, when I took over, suddenly I had no brakes, and no steering obviously. We almost went farming. In normal ops, the rear brake is for the instructor, and held a certain way can disable the front cabin system. Not good for how we operate them privately.

Regards to all
Jorgen

From: owner-l29-list-server(at)matronics.com (owner-l29-list-server(at)matronics.com) [mailto:owner-l29-list-server(at)matronics.com (owner-l29-list-server(at)matronics.com)] On Behalf Of Frank Deeth
Sent: Friday, 25 March 2016 21:07
To: l29-list(at)matronics.com (l29-list(at)matronics.com)
Subject: Re: Nitrogen Loss

I read once about an L-29 being operated in the UK where they disconnected the oxy system and plumbed those bottles into the pneumatic system, almost doubles the capacity if I recall...? Has anyone else looked at doing that?



Frank

Sent from my iPad
On Mar 26, 2016, at 4:20 AM, Bill Culberson <bculberson(at)staraviation.com (bculberson(at)staraviation.com)> wrote:
Quote:

Ultrasonic leak detector only works on the high pressure leaks (75-100 BAR), as it detects the specific audio signature of high pressure gas escaping. Canopy seals and brakes are at lower pressures and the soap and water test seems best.

I don’t use a Schrader valve but rather the original quarter turn valve but recently converted the N2 Cover to having a Schrader adapter “just in case”. My plane doesn’t leak much but discovered that with the cover changed and a good gasket the N2 cover that the N2 remains for weeks instead of days. Main check valve must be leaking.

I like the Hand valve at the tanks, what did you use? Pics?

Bill
N39DE

From: owner-l29-list-server(at)matronics.com (owner-l29-list-server(at)matronics.com) [mailto:owner-l29-list-server(at)matronics.com (owner-l29-list-server(at)matronics.com)] On Behalf Of Jorgen Nielsen
Sent: Friday, March 25, 2016 2:52 AM
To: l29-list(at)matronics.com (l29-list(at)matronics.com)
Subject: RE: Nitrogen Loss

I also tried an ultrasonic leak detector, got a very expensive version on trial for a week from a specialty supplier. Could not find anything using it either. Soapy water is messy but seems to work best.

My air system is modified, with a hand valve installed close to the bottles. When I am done flying, I shut it off. Also nice if using the L29 to go somewhere, turn it off after landing, turn it back on before flight, no losses.

From: owner-l29-list-server(at)matronics.com (owner-l29-list-server(at)matronics.com) [mailto:owner-l29-list-server(at)matronics.com (owner-l29-list-server(at)matronics.com)] On Behalf Of Anthony Royal
Sent: Friday, 25 March 2016 02:17
To: l29-list(at)matronics.com (l29-list(at)matronics.com)
Subject: Re: Nitrogen Loss

Hey guys,

Thanks for all your suggestions! John, I did the soapy water test on every fitting I could find all the way back to the fittings for the emergency bottle and beyond. ...tightened too. No Joy.



Bill, I think I did the top nut but missed the lower nut. I'll look at that next . Yeah, I'm 60 and a little too big to get into that small of quarters.



Hey Frank, thanks for the info too!



I'm also looking at disconnecting the the main pressurizing line line at the pressure reduction valve for the down stream items, after the nitrogen bottles, and capping off the line and then pressurizing the bottles. This should tell me if there is a leak anywhere upstream of the reduction valve in the main charging system. The emergency bottle holds pressure perfectly so no problems there.



According to the service manual, the minimum loss is 5 atm over 2 hours. So, I'm right on that limit at 2.5 atm per hour.



Thanks!

Tony









On Thursday, March 24, 2016 7:15 PM, John Cabrera <jetblast1(at)me.com (jetblast1(at)me.com)> wrote:


I don”t know if this is going to be of any help and some may laugh at me but i was chasing at leak in the rear canopy. Bought a fancy ultrasonic leak detector and could not find any leak. Finally decided to check with old fashion soapy water and a spray bottle. That worked.


John





Quote:

On Mar 23, 2016, at 8:22 AM, Anthony Royal <skyking76t(at)verizon.net (skyking76t(at)verizon.net)> wrote:


Guys, my L-29 has always held nitrogen for days without much loss of pressure. Other day I pressurized to 140 atm because of a long flight and day. Pressure bled off immediately from 140 to about 90 atm before I could get out of the hangar. And was totally empty the next day. I found several loose, original safety wired, connections not tight. Packing nut on the nitrogen purge valve was loose too. Tightened every fitting and thing I could find from nose to rear cockpit.



Now, if I pressurize to 50 atm, I will lose 30 atm in 12 hours. If I pressurize to 100 atm I lose 30 atm in 12 hours. Very consistent now. That's about 2.5 atm per hour. Any suggestions what else might cause such a consistent leak? Thinking maybe the pressure relief valve leaking? Check valve? Reading manuals and reviewing diagrams but thought maybe someone else may have run into this same problem and save a lot of time



Someone, in a post I can't find, suggested an ultrasonic tester of some sort to detect high pressure leaks. Does anyone know which one it was?



Also, looking for the glass lens for the taxi light. Rock must have hit mineand cracked it in half. Glued it back but would like to replacement. Also looking for connector to ARC EA-401A encoding altimeter.



Thanks for any info



Anthony












- The Matronics L29-List Email Forum -
 

Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:

http://www.matronics.com/Navigator?L29-List
Back to top
delfin29(at)me.com
Guest





PostPosted: Fri Mar 25, 2016 6:37 pm    Post subject: Nitrogen Loss Reply with quote

I think the best way is an air compressor, working automatically at 20 bars and stopping at 50.
My, installed by the tzechs and approved by the factory is perfectly working since 15 years. No need of ground support.
Jean de Roubin

Envoyé de mon iPhone

Le 25 mars 2016 à 19:58, Frank Deeth <tr.9(at)westnet.com.au (tr.9(at)westnet.com.au)> a écrit :
Quote:
Thanks Jorgen!

Sent from my iPhone

On 26 Mar 2016, at 6:50 AM, Jorgen Nielsen <jorgen.nielsen(at)mweb.co.za (jorgen.nielsen(at)mweb.co.za)> wrote:
Quote:
<![endif]--> <![endif]-->
Mine is also done like that. I only posted half the story earlier, herewith then the full story J

I don’t use oxygen, so repurposed the tanks.

My oxygen tanks have a tap on them, close to the bottles, and a pressure gauge. The tap & gauge is situated in the nose compartment.
My normal air bottle (N2) also have a tap on them, and a gauge, also in the nose compartment.
So far, 2 separate systems.
After the taps, they are interconnected via a T, output goes to the air system.

Benefits:
Closing the valves means no leaks when she is standing.
Having the 2 systems that close means I can go away for a weekend with no ground support, or for example a 3 hop ferry I did a while back. At the destination, close the active system. For the next flight, pick a system and open valve. When the system is empty use the next one.

To fill, if its just a normal flight from home base, I open the valve for whichever system is in use, and fill normally. For extended flights, one can fill one system at a time, or open both and fill both, then close one.

So far, completely trouble free for a number of years.

I will have to take some pics when at the airport. I used spare hand operated valves, similar to the pressure release inside the cockpit. I never did the work myself, I have a Russian guy who does all my maintenance, I just dreamt it up and asked him to do it.

Another mod we did: my front / rear braking system has been reversed. I was once taxying with pax, and asked them to hold the brake while I did something. On release, when I took over, suddenly I had no brakes, and no steering obviously. We almost went farming. In normal ops, the rear brake is for the instructor, and held a certain way can disable the front cabin system. Not good for how we operate them privately.

Regards to all
Jorgen

From: owner-l29-list-server(at)matronics.com (owner-l29-list-server(at)matronics.com) [mailto:owner-l29-list-server(at)matronics.com (owner-l29-list-server(at)matronics.com)] On Behalf Of Frank Deeth
Sent: Friday, 25 March 2016 21:07
To: l29-list(at)matronics.com (l29-list(at)matronics.com)
Subject: Re: Nitrogen Loss

I read once about an L-29 being operated in the UK where they disconnected the oxy system and plumbed those bottles into the pneumatic system, almost doubles the capacity if I recall...? Has anyone else looked at doing that?



Frank

Sent from my iPad
On Mar 26, 2016, at 4:20 AM, Bill Culberson <bculberson(at)staraviation.com (bculberson(at)staraviation.com)> wrote:
Quote:

Ultrasonic leak detector only works on the high pressure leaks (75-100 BAR), as it detects the specific audio signature of high pressure gas escaping. Canopy seals and brakes are at lower pressures and the soap and water test seems best.

I don’t use a Schrader valve but rather the original quarter turn valve but recently converted the N2 Cover to having a Schrader adapter “just in case”. My plane doesn’t leak much but discovered that with the cover changed and a good gasket the N2 cover that the N2 remains for weeks instead of days. Main check valve must be leaking.

I like the Hand valve at the tanks, what did you use? Pics?

Bill
N39DE

From: owner-l29-list-server(at)matronics.com (owner-l29-list-server(at)matronics.com) [mailto:owner-l29-list-server(at)matronics.com (owner-l29-list-server(at)matronics.com)] On Behalf Of Jorgen Nielsen
Sent: Friday, March 25, 2016 2:52 AM
To: l29-list(at)matronics.com (l29-list(at)matronics.com)
Subject: RE: Nitrogen Loss

I also tried an ultrasonic leak detector, got a very expensive version on trial for a week from a specialty supplier. Could not find anything using it either. Soapy water is messy but seems to work best.

My air system is modified, with a hand valve installed close to the bottles. When I am done flying, I shut it off. Also nice if using the L29 to go somewhere, turn it off after landing, turn it back on before flight, no losses.

From: owner-l29-list-server(at)matronics.com (owner-l29-list-server(at)matronics.com) [mailto:owner-l29-list-server(at)matronics.com (owner-l29-list-server(at)matronics.com)] On Behalf Of Anthony Royal
Sent: Friday, 25 March 2016 02:17
To: l29-list(at)matronics.com (l29-list(at)matronics.com)
Subject: Re: Nitrogen Loss

Hey guys,

Thanks for all your suggestions! John, I did the soapy water test on every fitting I could find all the way back to the fittings for the emergency bottle and beyond. ...tightened too. No Joy.



Bill, I think I did the top nut but missed the lower nut. I'll look at that next . Yeah, I'm 60 and a little too big to get into that small of quarters.



Hey Frank, thanks for the info too!



I'm also looking at disconnecting the the main pressurizing line line at the pressure reduction valve for the down stream items, after the nitrogen bottles, and capping off the line and then pressurizing the bottles. This should tell me if there is a leak anywhere upstream of the reduction valve in the main charging system. The emergency bottle holds pressure perfectly so no problems there.



According to the service manual, the minimum loss is 5 atm over 2 hours. So, I'm right on that limit at 2.5 atm per hour.



Thanks!

Tony









On Thursday, March 24, 2016 7:15 PM, John Cabrera <jetblast1(at)me.com (jetblast1(at)me.com)> wrote:


I don”t know if this is going to be of any help and some may laugh at me but i was chasing at leak in the rear canopy. Bought a fancy ultrasonic leak detector and could not find any leak. Finally decided to check with old fashion soapy water and a spray bottle. That worked.


John





Quote:

On Mar 23, 2016, at 8:22 AM, Anthony Royal <skyking76t(at)verizon.net (skyking76t(at)verizon.net)> wrote:


Guys, my L-29 has always held nitrogen for days without much loss of pressure. Other day I pressurized to 140 atm because of a long flight and day. Pressure bled off immediately from 140 to about 90 atm before I could get out of the hangar. And was totally empty the next day. I found several loose, original safety wired, connections not tight. Packing nut on the nitrogen purge valve was loose too. Tightened every fitting and thing I could find from nose to rear cockpit.



Now, if I pressurize to 50 atm, I will lose 30 atm in 12 hours. If I pressurize to 100 atm I lose 30 atm in 12 hours. Very consistent now. That's about 2.5 atm per hour. Any suggestions what else might cause such a consistent leak? Thinking maybe the pressure relief valve leaking? Check valve? Reading manuals and reviewing diagrams but thought maybe someone else may have run into this same problem and save a lot of time



Someone, in a post I can't find, suggested an ultrasonic tester of some sort to detect high pressure leaks. Does anyone know which one it was?



Also, looking for the glass lens for the taxi light. Rock must have hit mineand cracked it in half. Glued it back but would like to replacement. Also looking for connector to ARC EA-401A encoding altimeter.



Thanks for any info



Anthony













- The Matronics L29-List Email Forum -
 

Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:

http://www.matronics.com/Navigator?L29-List
Back to top
migfighter42(at)gmail.com
Guest





PostPosted: Fri Mar 25, 2016 6:53 pm    Post subject: Nitrogen Loss Reply with quote

What type of air compressor? Are they available?
Sent from my T-Mobile 4G LTE Device

-------- Original message --------
From: Jean de Roubin <delfin29(at)me.com>
Date: 3/25/2016 10:36 PM (GMT-05:00)
To: l29-list(at)matronics.com
Subject: Re: L29-List: Nitrogen Loss

I think the best way is an air compressor, working automatically at 20 bars and stopping at 50.
My, installed by the tzechs and approved by the factory is perfectly working since 15 years. No need of ground support.
Jean de Roubin

Envoyé de mon iPhone

Le 25 mars 2016 à 19:58, Frank Deeth <tr.9(at)westnet.com.au (tr.9(at)westnet.com.au)> a écrit:
Quote:
Thanks Jorgen!

Sent from my iPhone

On 26 Mar 2016, at 6:50 AM, Jorgen Nielsen <jorgen.nielsen(at)mweb.co.za (jorgen.nielsen(at)mweb.co.za)> wrote:
Quote:
<![endif]--> <![endif]-->
Mine is also done like that. I only posted half the story earlier, herewith then the full story J

I don’t use oxygen, so repurposed the tanks.

My oxygen tanks have a tap on them, close to the bottles, and a pressure gauge. The tap & gauge is situated in the nose compartment.
My normal air bottle (N2) also have a tap on them, and a gauge, also in the nose compartment.
So far, 2 separate systems.
After the taps, they are interconnected via a T, output goes to the air system.

Benefits:
Closing the valves means no leaks when she is standing.
Having the 2 systems that close means I can go away for a weekend with no ground support, or for example a 3 hop ferry I did a while back. At the destination, close the active system. For the next flight, pick a system and open valve. When the system is empty use the next one.

To fill, if its just a normal flight from home base, I open the valve for whichever system is in use, and fill normally. For extended flights, one can fill one system at a time, or open both and fill both, then close one.

So far, completely trouble free for a number of years.

I will have to take some pics when at the airport. I used spare hand operated valves, similar to the pressure release inside the cockpit. I never did the work myself, I have a Russian guy who does all my maintenance, I just dreamt it up and asked him to do it.

Another mod we did: my front / rear braking system has been reversed. I was once taxying with pax, and asked them to hold the brake while I did something. On release, when I took over, suddenly I had no brakes, and no steering obviously. We almost went farming. In normal ops, the rear brake is for the instructor, and held a certain way can disable the front cabin system. Not good for how we operate them privately.

Regards to all
Jorgen

From: owner-l29-list-server(at)matronics.com (owner-l29-list-server(at)matronics.com) [mailto:owner-l29-list-server(at)matronics.com (owner-l29-list-server(at)matronics.com)] On Behalf Of Frank Deeth
Sent: Friday, 25 March 2016 21:07
To: l29-list(at)matronics.com (l29-list(at)matronics.com)
Subject: Re: L29-List: Nitrogen Loss

I read once about an L-29 being operated in the UK where they disconnected the oxy system and plumbed those bottles into the pneumatic system, almost doubles the capacity if I recall...? Has anyone else looked at doing that?



Frank

Sent from my iPad
On Mar 26, 2016, at 4:20 AM, Bill Culberson <bculberson(at)staraviation.com (bculberson(at)staraviation.com)> wrote:
Quote:

Ultrasonic leak detector only works on the high pressure leaks (75-100 BAR), as it detects the specific audio signature of high pressure gas escaping. Canopy seals and brakes are at lower pressures and the soap and water test seems best.

I don’t use a Schrader valve but rather the original quarter turn valve but recently converted the N2 Cover to having a Schrader adapter “just in case”. My plane doesn’t leak much but discovered that with the cover changed and a good gasket the N2 cover that the N2 remains for weeks instead of days. Main check valve must be leaking.

I like the Hand valve at the tanks, what did you use? Pics?

Bill
N39DE

From: owner-l29-list-server(at)matronics.com (owner-l29-list-server(at)matronics.com) [mailto:owner-l29-list-server(at)matronics.com (owner-l29-list-server(at)matronics.com)] On Behalf Of Jorgen Nielsen
Sent: Friday, March 25, 2016 2:52 AM
To: l29-list(at)matronics.com (l29-list(at)matronics.com)
Subject: RE: L29-List: Nitrogen Loss

I also tried an ultrasonic leak detector, got a very expensive version on trial for a week from a specialty supplier. Could not find anything using it either. Soapy water is messy but seems to work best.

My air system is modified, with a hand valve installed close to the bottles. When I am done flying, I shut it off. Also nice if using the L29 to go somewhere, turn it off after landing, turn it back on before flight, no losses.

From: owner-l29-list-server(at)matronics.com (owner-l29-list-server(at)matronics.com) [mailto:owner-l29-list-server(at)matronics.com (owner-l29-list-server(at)matronics.com)] On Behalf Of Anthony Royal
Sent: Friday, 25 March 2016 02:17
To: l29-list(at)matronics.com (l29-list(at)matronics.com)
Subject: Re: L29-List: Nitrogen Loss

Hey guys,

Thanks for all your suggestions! John, I did the soapy water test on every fitting I could find all the way back to the fittings for the emergency bottle and beyond. ...tightened too. No Joy.



Bill, I think I did the top nut but missed the lower nut. I'll look at that next . Yeah, I'm 60 and a little too big to get into that small of quarters.



Hey Frank, thanks for the info too!



I'm also looking at disconnecting the the main pressurizing line line at the pressure reduction valve for the down stream items, after the nitrogen bottles, and capping off the line and then pressurizing the bottles. This should tell me if there is a leak anywhere upstream of the reduction valve in the main charging system. The emergency bottle holds pressure perfectly so no problems there.



According to the service manual, the minimum loss is 5 atm over 2 hours. So, I'm right on that limit at 2.5 atm per hour.



Thanks!

Tony









On Thursday, March 24, 2016 7:15 PM, John Cabrera <jetblast1(at)me.com (jetblast1(at)me.com)> wrote:


I don”t know if this is going to be of any help and some may laugh at me but i was chasing at leak in the rear canopy. Bought a fancy ultrasonic leak detector and could not find any leak. Finally decided to check with old fashion soapy water and a spray bottle. That worked.


John





Quote:

On Mar 23, 2016, at 8:22 AM, Anthony Royal <skyking76t(at)verizon.net (skyking76t(at)verizon.net)> wrote:


Guys, my L-29 has always held nitrogen for days without much loss of pressure. Other day I pressurized to 140 atm because of a long flight and day. Pressure bled off immediately from 140 to about 90 atm before I could get out of the hangar. And was totally empty the next day. I found several loose, original safety wired, connections not tight. Packing nut on the nitrogen purge valve was loose too. Tightened every fitting and thing I could find from nose to rear cockpit.



Now, if I pressurize to 50 atm, I will lose 30 atm in 12 hours. If I pressurize to 100 atm I lose 30 atm in 12 hours. Very consistent now. That's about 2.5 atm per hour. Any suggestions what else might cause such a consistent leak? Thinking maybe the pressure relief valve leaking? Check valve? Reading manuals and reviewing diagrams but thought maybe someone else may have run into this same problem and save a lot of time



Someone, in a post I can't find, suggested an ultrasonic tester of some sort to detect high pressure leaks. Does anyone know which one it was?



Also, looking for the glass lens for the taxi light. Rock must have hit mineand cracked it in half. Glued it back but would like to replacement. Also looking for connector to ARC EA-401A encoding altimeter.



Thanks for any info



Anthony













- The Matronics L29-List Email Forum -
 

Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:

http://www.matronics.com/Navigator?L29-List
Back to top
Dawg



Joined: 19 May 2013
Posts: 355

PostPosted: Fri Mar 25, 2016 10:26 pm    Post subject: Nitrogen Loss Reply with quote

Mine has been that way for 25 years. I converted everything, used the oxygen valve in the cockpit. When my brake pressure gets low, I open the valve and top it off.
On Mar 25, 2016, at 13:07, Frank Deeth <tr.9(at)westnet.com.au (tr.9(at)westnet.com.au)> wrote:
Quote:
I read once about an L-29 being operated in the UK where they disconnected the oxy system and plumbed those bottles into the pneumatic system, almost doubles the capacity if I recall...? Has anyone else looked at doing that?
Frank

Sent from my iPad

On Mar 26, 2016, at 4:20 AM, Bill Culberson <bculberson(at)staraviation.com (bculberson(at)staraviation.com)> wrote:
Quote:
Ultrasonic leak detector only works on the high pressure leaks (75-100 BAR), as it detects the specific audio signature of high pressure gas escaping. Canopy seals and brakes are at lower pressures and the soap and water test seems best.

I dont use a Schrader valve but rather the original quarter turn valve but recently converted the N2 Cover to having a Schrader adapter just in case. My plane doesnt leak much but discovered that with the cover changed and a good gasket the N2 cover that the N2 remains for weeks instead of days. Main check valve must be leaking.

I like the Hand valve at the tanks, what did you use? Pics?

Bill
N39DE

From: owner-l29-list-server(at)matronics.com (owner-l29-list-server(at)matronics.com) [mailto:owner-l29-list-server(at)matronics.com (owner-l29-list-server(at)matronics.com)] On Behalf Of Jorgen Nielsen
Sent: Friday, March 25, 2016 2:52 AM
To: l29-list(at)matronics.com (l29-list(at)matronics.com)
Subject: RE: Nitrogen Loss

I also tried an ultrasonic leak detector, got a very expensive version on trial for a week from a specialty supplier. Could not find anything using it either. Soapy water is messy but seems to work best.

My air system is modified, with a hand valve installed close to the bottles. When I am done flying, I shut it off. Also nice if using the L29 to go somewhere, turn it off after landing, turn it back on before flight, no losses.

From: owner-l29-list-server(at)matronics.com (owner-l29-list-server(at)matronics.com) [mailto:owner-l29-list-server(at)matronics.com (owner-l29-list-server(at)matronics.com)] On Behalf Of Anthony Royal
Sent: Friday, 25 March 2016 02:17
To: l29-list(at)matronics.com (l29-list(at)matronics.com)
Subject: Re: Nitrogen Loss

Hey guys,

Thanks for all your suggestions! John, I did the soapy water test on every fitting I could find all the way back to the fittings for the emergency bottle and beyond. ...tightened too. No Joy.



Bill, I think I did the top nut but missed the lower nut. I'll look at that next . Yeah, I'm 60 and a little too big to get into that small of quarters.



Hey Frank, thanks for the info too!



I'm also looking at disconnecting the the main pressurizing line line at the pressure reduction valve for the down stream items, after the nitrogen bottles, and capping off the line and then pressurizing the bottles. This should tell me if there is a leak anywhere upstream of the reduction valve in the main charging system. The emergency bottle holds pressure perfectly so no problems there.



According to the service manual, the minimum loss is 5 atm over 2 hours. So, I'm right on that limit at 2.5 atm per hour.



Thanks!

Tony







On Thursday, March 24, 2016 7:15 PM, John Cabrera <jetblast1(at)me.com (jetblast1(at)me.com)> wrote:
I dont know if this is going to be of any help and some may laugh at me but i was chasing at leak in the rear canopy. Bought a fancy ultrasonic leak detector and could not find any leak. Finally decided to check with old fashion soapy water and a spray bottle. That worked.


John






Quote:
On Mar 23, 2016, at 8:22 AM, Anthony Royal <skyking76t(at)verizon.net (skyking76t(at)verizon.net)> wrote:


Guys, my L-29 has always held nitrogen for days without much loss of pressure. Other day I pressurized to 140 atm because of a long flight and day. Pressure bled off immediately from 140 to about 90 atm before I could get out of the hangar. And was totally empty the next day. I found several loose, original safety wired, connections not tight. Packing nut on the nitrogen purge valve was loose too. Tightened every fitting and thing I could find from nose to rear cockpit.



Now, if I pressurize to 50 atm, I will lose 30 atm in 12 hours. If I pressurize to 100 atm I lose 30 atm in 12 hours. Very consistent now. That's about 2.5 atm per hour. Any suggestions what else might cause such a consistent leak? Thinking maybe the pressure relief valve leaking? Check valve? Reading manuals and reviewing diagrams but thought maybe someone else may have run into this same problem and save a lot of time



Someone, in a post I can't find, suggested an ultrasonic tester of some sort to detect high pressure leaks. Does anyone know which one it was?



Also, looking for the glass lens for the taxi light. Rock must have hit mineand cracked it in half. Glued it back but would like to replacement. Also looking for connector to ARC EA-401A encoding altimeter.



Thanks for any info



Anthony




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Dawg



Joined: 19 May 2013
Posts: 355

PostPosted: Fri Mar 25, 2016 10:27 pm    Post subject: Nitrogen Loss Reply with quote

send description and pix.
On Mar 25, 2016, at 20:36, Jean de Roubin <delfin29(at)me.com (delfin29(at)me.com)> wrote:
Quote:
I think the best way is an air compressor, working automatically at 20 bars and stopping at 50.
My, installed by the tzechs and approved by the factory is perfectly working since 15 years. No need of ground support.
Jean de Roubin

Envoy de mon iPhone

Le 25 mars 2016 19:58, Frank Deeth <tr.9(at)westnet.com.au (tr.9(at)westnet.com.au)> a crit :
Quote:
Thanks Jorgen!

Sent from my iPhone

On 26 Mar 2016, at 6:50 AM, Jorgen Nielsen <jorgen.nielsen(at)mweb.co.za (jorgen.nielsen(at)mweb.co.za)> wrote:
Quote:
Mine is also done like that. I only posted half the story earlier, herewith then the full story J

I dont use oxygen, so repurposed the tanks.

My oxygen tanks have a tap on them, close to the bottles, and a pressure gauge. The tap & gauge is situated in the nose compartment.
My normal air bottle (N2) also have a tap on them, and a gauge, also in the nose compartment.
So far, 2 separate systems.
After the taps, they are interconnected via a T, output goes to the air system.

Benefits:
Closing the valves means no leaks when she is standing.
Having the 2 systems that close means I can go away for a weekend with no ground support, or for example a 3 hop ferry I did a while back. At the destination, close the active system. For the next flight, pick a system and open valve. When the system is empty use the next one.

To fill, if its just a normal flight from home base, I open the valve for whichever system is in use, and fill normally. For extended flights, one can fill one system at a time, or open both and fill both, then close one.

So far, completely trouble free for a number of years.

I will have to take some pics when at the airport. I used spare hand operated valves, similar to the pressure release inside the cockpit. I never did the work myself, I have a Russian guy who does all my maintenance, I just dreamt it up and asked him to do it.

Another mod we did: my front / rear braking system has been reversed. I was once taxying with pax, and asked them to hold the brake while I did something. On release, when I took over, suddenly I had no brakes, and no steering obviously. We almost went farming. In normal ops, the rear brake is for the instructor, and held a certain way can disable the front cabin system. Not good for how we operate them privately.

Regards to all
Jorgen

From: owner-l29-list-server(at)matronics.com (owner-l29-list-server(at)matronics.com) [mailto:owner-l29-list-server(at)matronics.com (owner-l29-list-server(at)matronics.com)] On Behalf Of Frank Deeth
Sent: Friday, 25 March 2016 21:07
To: l29-list(at)matronics.com (l29-list(at)matronics.com)
Subject: Re: Nitrogen Loss

I read once about an L-29 being operated in the UK where they disconnected the oxy system and plumbed those bottles into the pneumatic system, almost doubles the capacity if I recall...? Has anyone else looked at doing that?



Frank

Sent from my iPad

On Mar 26, 2016, at 4:20 AM, Bill Culberson <bculberson(at)staraviation.com (bculberson(at)staraviation.com)> wrote:
Quote:
Ultrasonic leak detector only works on the high pressure leaks (75-100 BAR), as it detects the specific audio signature of high pressure gas escaping. Canopy seals and brakes are at lower pressures and the soap and water test seems best.

I dont use a Schrader valve but rather the original quarter turn valve but recently converted the N2 Cover to having a Schrader adapter just in case. My plane doesnt leak much but discovered that with the cover changed and a good gasket the N2 cover that the N2 remains for weeks instead of days. Main check valve must be leaking.

I like the Hand valve at the tanks, what did you use? Pics?

Bill
N39DE

From: owner-l29-list-server(at)matronics.com (owner-l29-list-server(at)matronics.com) [mailto:owner-l29-list-server(at)matronics.com (owner-l29-list-server(at)matronics.com)] On Behalf Of Jorgen Nielsen
Sent: Friday, March 25, 2016 2:52 AM
To: l29-list(at)matronics.com (l29-list(at)matronics.com)
Subject: RE: Nitrogen Loss

I also tried an ultrasonic leak detector, got a very expensive version on trial for a week from a specialty supplier. Could not find anything using it either. Soapy water is messy but seems to work best.

My air system is modified, with a hand valve installed close to the bottles. When I am done flying, I shut it off. Also nice if using the L29 to go somewhere, turn it off after landing, turn it back on before flight, no losses.

From: owner-l29-list-server(at)matronics.com (owner-l29-list-server(at)matronics.com) [mailto:owner-l29-list-server(at)matronics.com (owner-l29-list-server(at)matronics.com)] On Behalf Of Anthony Royal
Sent: Friday, 25 March 2016 02:17
To: l29-list(at)matronics.com (l29-list(at)matronics.com)
Subject: Re: Nitrogen Loss

Hey guys,

Thanks for all your suggestions! John, I did the soapy water test on every fitting I could find all the way back to the fittings for the emergency bottle and beyond. ...tightened too. No Joy.



Bill, I think I did the top nut but missed the lower nut. I'll look at that next . Yeah, I'm 60 and a little too big to get into that small of quarters.



Hey Frank, thanks for the info too!



I'm also looking at disconnecting the the main pressurizing line line at the pressure reduction valve for the down stream items, after the nitrogen bottles, and capping off the line and then pressurizing the bottles. This should tell me if there is a leak anywhere upstream of the reduction valve in the main charging system. The emergency bottle holds pressure perfectly so no problems there.



According to the service manual, the minimum loss is 5 atm over 2 hours. So, I'm right on that limit at 2.5 atm per hour.



Thanks!

Tony







On Thursday, March 24, 2016 7:15 PM, John Cabrera <jetblast1(at)me.com (jetblast1(at)me.com)> wrote:
I dont know if this is going to be of any help and some may laugh at me but i was chasing at leak in the rear canopy. Bought a fancy ultrasonic leak detector and could not find any leak. Finally decided to check with old fashion soapy water and a spray bottle. That worked.


John






Quote:
On Mar 23, 2016, at 8:22 AM, Anthony Royal <skyking76t(at)verizon.net (skyking76t(at)verizon.net)> wrote:


Guys, my L-29 has always held nitrogen for days without much loss of pressure. Other day I pressurized to 140 atm because of a long flight and day. Pressure bled off immediately from 140 to about 90 atm before I could get out of the hangar. And was totally empty the next day. I found several loose, original safety wired, connections not tight. Packing nut on the nitrogen purge valve was loose too. Tightened every fitting and thing I could find from nose to rear cockpit.



Now, if I pressurize to 50 atm, I will lose 30 atm in 12 hours. If I pressurize to 100 atm I lose 30 atm in 12 hours. Very consistent now. That's about 2.5 atm per hour. Any suggestions what else might cause such a consistent leak? Thinking maybe the pressure relief valve leaking? Check valve? Reading manuals and reviewing diagrams but thought maybe someone else may have run into this same problem and save a lot of time



Someone, in a post I can't find, suggested an ultrasonic tester of some sort to detect high pressure leaks. Does anyone know which one it was?



Also, looking for the glass lens for the taxi light. Rock must have hit mineand cracked it in half. Glued it back but would like to replacement. Also looking for connector to ARC EA-401A encoding altimeter.



Thanks for any info



Anthony






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Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:

http://www.matronics.com/Navigator?L29-List

_________________
Dawg
Back to top
View user's profile Send private message
skyking76t(at)verizon.net
Guest





PostPosted: Sat Mar 26, 2016 3:12 pm    Post subject: Nitrogen Loss Reply with quote

I would be interested too!
Found part of my leak problem.Removed the check valve that prevents nitrogen from the Nitro bottles from flowing back out of bottles. The flare on the check valve had a large burr,ridge on it. Not sure how that could have happened. Smoothed it out ( yes I know you can't really repair because you alter the angle) and used some aircraft grade sealer made for sealing a damaged flare and put back together for a test. Added 50 atm nitro last night and still had 20 atm left over 24 hours later and was stable. May leak at higher pressure but it is a start. Also removed the nitrogen tank purge/drain valve. Packing nut was still a little loose and it looked to have a little something on the sealing seat. When I first tried to tighten in the plane I got a significant increase in nitrogen pressure time. I'm working my way back toward the cockpit. Checked the 2 connections at the brake valve beside the stick. All seems to be very tight.
Anybody have a new or good used check valve?

On Saturday, March 26, 2016 2:32 AM, Bill Geipel <l129bs(at)gmail.com> wrote:



send description and pix.On Mar 25, 2016, at 20:36, Jean de Roubin <delfin29(at)me.com (delfin29(at)me.com)> wrote:
Quote:
I think the best way is an air compressor, working automatically at 20 bars and stopping at 50.
My, installed by the tzechs and approved by the factory is perfectly working since 15 years. No need of ground support.
Jean de RoubinEnvoyé de mon iPhone
Le 25 mars 2016 à 19:58, Frank Deeth <tr.9(at)westnet.com.au (tr.9(at)westnet.com.au)> a écrit :
Quote:
Thanks Jorgen!Sent from my iPhone
On 26 Mar 2016, at 6:50 AM, Jorgen Nielsen <jorgen.nielsen(at)mweb.co.za (jorgen.nielsen(at)mweb.co.za)> wrote:
Quote:
Mine is also done like that. I only posted half the story earlier, herewith then the full story J

I don’t use oxygen, so repurposed the tanks.

My oxygen tanks have a tap on them, close to the bottles, and a pressure gauge. The tap & gauge is situated in the nose compartment.
My normal air bottle (N2) also have a tap on them, and a gauge, also in the nose compartment.
So far, 2 separate systems.
After the taps, they are interconnected via a T, output goes to the air system.

Benefits:
Closing the valves means no leaks when she is standing.
Having the 2 systems that close means I can go away for a weekend with no ground support, or for example a 3 hop ferry I did a while back. At the destination, close the active system. For the next flight, pick a system and open valve. When the system is empty use the next one.

To fill, if its just a normal flight from home base, I open the valve for whichever system is in use, and fill normally. For extended flights, one can fill one system at a time, or open both and fill both, then close one.

So far, completely trouble free for a number of years.

I will have to take some pics when at the airport. I used spare hand operated valves, similar to the pressure release inside the cockpit. I never did the work myself, I have a Russian guy who does all my maintenance, I just dreamt it up and asked him to do it.

Another mod we did: my front / rear braking system has been reversed. I was once taxying with pax, and asked them to hold the brake while I did something. On release, when I took over, suddenly I had no brakes, and no steering obviously. We almost went farming. In normal ops, the rear brake is for the instructor, and held a certain way can disable the front cabin system. Not good for how we operate them privately.

Regards to all
Jorgen

From: owner-l29-list-server(at)matronics.com (owner-l29-list-server(at)matronics.com) [mailto:owner-l29-list-server(at)matronics.com (owner-l29-list-server(at)matronics.com)] On Behalf Of Frank DeethSent: Friday, 25 March 2016 21:07To:l29-list(at)matronics.com (l29-list(at)matronics.com)Subject: Re: Nitrogen Loss

I read once about an L-29 being operated in the UK where they disconnected the oxy system and plumbed those bottles into the pneumatic system, almost doubles the capacity if I recall...? Has anyone else looked at doing that?



FrankSent from my iPad

On Mar 26, 2016, at 4:20 AM, Bill Culberson <bculberson(at)staraviation.com (bculberson(at)staraviation.com)> wrote:

Quote:
Ultrasonic leak detector only works on the high pressure leaks (75-100 BAR), as it detects the specific audio signature of high pressure gas escaping. Canopy seals and brakes are at lower pressures and the soap and water test seems best.

I don’t use a Schrader valve but rather the original quarter turn valve but recently converted the N2 Cover to having a Schrader adapter “just in case”. My plane doesn’t leak much but discovered that with the cover changed and a good gasket the N2 cover that the N2 remains for weeks instead of days. Main check valve must be leaking.

I like the Hand valve at the tanks, what did you use? Pics?

Bill
N39DE
[url=] [/url]
From: owner-l29-list-server(at)matronics.com (owner-l29-list-server(at)matronics.com) [mailto:owner-l29-list-server(at)matronics.com (owner-l29-list-server(at)matronics.com)] On Behalf Of Jorgen NielsenSent: Friday, March 25, 2016 2:52 AMTo: l29-list(at)matronics.com (l29-list(at)matronics.com)Subject: RE: Nitrogen Loss

I also tried an ultrasonic leak detector, got a very expensive version on trial for a week from a specialty supplier. Could not find anything using it either. Soapy water is messy but seems to work best.

My air system is modified, with a hand valve installed close to the bottles. When I am done flying, I shut it off. Also nice if using the L29 to go somewhere, turn it off after landing, turn it back on before flight, no losses.

From: owner-l29-list-server(at)matronics.com (owner-l29-list-server(at)matronics.com) [mailto:owner-l29-list-server(at)matronics.com (owner-l29-list-server(at)matronics.com)] On Behalf Of Anthony RoyalSent: Friday, 25 March 2016 02:17To: l29-list(at)matronics.com (l29-list(at)matronics.com)Subject: Re: Nitrogen Loss

Hey guys,

Thanks for all your suggestions! John, I did the soapy water test on every fitting I could find all the way back to the fittings for the emergency bottle and beyond. ...tightened too. No Joy.



Bill, I think I did the top nut but missed the lower nut. I'll look at that next . Yeah, I'm 60 and a little too big to get into that small of quarters.



Hey Frank, thanks for the info too!



I'm also looking at disconnecting the the main pressurizing line line at the pressure reduction valve for the down stream items, after the nitrogen bottles, and capping off the line and then pressurizing the bottles. This should tell me if there is a leak anywhere upstream of the reduction valve in the main charging system. The emergency bottle holds pressure perfectly so no problems there.



According to the service manual, the minimum loss is 5 atm over 2 hours. So, I'm right on that limit at 2.5 atm per hour.



Thanks!

Tony









On Thursday, March 24, 2016 7:15 PM, John Cabrera <jetblast1(at)me.com (jetblast1(at)me.com)> wrote:


I don”t know if this is going to be of any help and some may laugh at me but i was chasing at leak in the rear canopy. Bought a fancy ultrasonic leak detector and could not find any leak. Finally decided to check with old fashion soapy water and a spray bottle. That worked.


John






Quote:
On Mar 23, 2016, at 8:22 AM, Anthony Royal <skyking76t(at)verizon.net (skyking76t(at)verizon.net)> wrote:


Guys, my L-29 has always held nitrogen for days without much loss of pressure. Other day I pressurized to 140 atm because of a long flight and day. Pressure bled off immediately from 140 to about 90 atm before I could get out of the hangar. And was totally empty the next day. I found several loose, original safety wired, connections not tight. Packing nut on the nitrogen purge valve was loose too. Tightened every fitting and thing I could find from nose to rear cockpit.



Now, if I pressurize to 50 atm, I will lose 30 atm in 12 hours. If I pressurize to 100 atm I lose 30 atm in 12 hours. Very consistent now. That's about 2.5 atm per hour. Any suggestions what else might cause such a consistent leak? Thinking maybe the pressure relief valve leaking? Check valve? Reading manuals and reviewing diagrams but thought maybe someone else may have run into this same problem and save a lot of time



Someone, in a post I can't find, suggested an ultrasonic tester of some sort to detect high pressure leaks. Does anyone know which one it was?



Also, looking for the glass lens for the taxi light. Rock must have hit mineand cracked it in half. Glued it back but would like to replacement. Also looking for connector to ARC EA-401A encoding altimeter.



Thanks for any info



Anthony






- The Matronics L29-List Email Forum -
 

Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:

http://www.matronics.com/Navigator?L29-List
Back to top
skyking76t(at)verizon.net
Guest





PostPosted: Sat Mar 26, 2016 6:12 pm    Post subject: Nitrogen Loss Reply with quote

Part number for check valve is 998 4A. In line just before going into bottom nitro tank

On Saturday, March 26, 2016 7:08 PM, Anthony Royal <skyking76t(at)verizon.net> wrote:



I would be interested too!

Found part of my leak problem.Removed the check valve that prevents nitrogen from the Nitro bottles from flowing back out of bottles. The flare on the check valve had a large burr,ridge on it. Not sure how that could have happened. Smoothed it out ( yes I know you can't really repair because you alter the angle) and used some aircraft grade sealer made for sealing a damaged flare and put back together for a test. Added 50 atm nitro last night and still had 20 atm left over 24 hours later and was stable. May leak at higher pressure but it is a start. Also removed the nitrogen tank purge/drain valve. Packing nut was still a little loose and it looked to have a little something on the sealing seat. When I first tried to tighten in the plane I got a significant increase in nitrogen pressure time. I'm working my way back toward the cockpit. Checked the 2 connections at the brake valve beside the stick. All seems to be very tight.

Anybody have a new or good used check valve?

On Saturday, March 26, 2016 2:32 AM, Bill Geipel <l129bs(at)gmail.com> wrote:
send description and pix.On Mar 25, 2016, at 20:36, Jean de Roubin <delfin29(at)me.com (delfin29(at)me.com)> wrote:
Quote:
I think the best way is an air compressor, working automatically at 20 bars and stopping at 50.
My, installed by the tzechs and approved by the factory is perfectly working since 15 years. No need of ground support.
Jean de RoubinEnvoyé de mon iPhone
Le 25 mars 2016 à 19:58, Frank Deeth <tr.9(at)westnet.com.au (tr.9(at)westnet.com.au)> a écrit :
Quote:
Thanks Jorgen!Sent from my iPhone
On 26 Mar 2016, at 6:50 AM, Jorgen Nielsen <jorgen.nielsen(at)mweb.co.za (jorgen.nielsen(at)mweb.co.za)> wrote:
Quote:
Mine is also done like that. I only posted half the story earlier, herewith then the full story J

I don’t use oxygen, so repurposed the tanks.

My oxygen tanks have a tap on them, close to the bottles, and a pressure gauge. The tap & gauge is situated in the nose compartment.
My normal air bottle (N2) also have a tap on them, and a gauge, also in the nose compartment.
So far, 2 separate systems.
After the taps, they are interconnected via a T, output goes to the air system.

Benefits:
Closing the valves means no leaks when she is standing.
Having the 2 systems that close means I can go away for a weekend with no ground support, or for example a 3 hop ferry I did a while back. At the destination, close the active system. For the next flight, pick a system and open valve. When the system is empty use the next one.

To fill, if its just a normal flight from home base, I open the valve for whichever system is in use, and fill normally. For extended flights, one can fill one system at a time, or open both and fill both, then close one.

So far, completely trouble free for a number of years.

I will have to take some pics when at the airport. I used spare hand operated valves, similar to the pressure release inside the cockpit. I never did the work myself, I have a Russian guy who does all my maintenance, I just dreamt it up and asked him to do it.

Another mod we did: my front / rear braking system has been reversed. I was once taxying with pax, and asked them to hold the brake while I did something. On release, when I took over, suddenly I had no brakes, and no steering obviously. We almost went farming. In normal ops, the rear brake is for the instructor, and held a certain way can disable the front cabin system. Not good for how we operate them privately.

Regards to all
Jorgen

From: owner-l29-list-server(at)matronics.com (owner-l29-list-server(at)matronics.com) [mailto:owner-l29-list-server(at)matronics.com (owner-l29-list-server(at)matronics.com)] On Behalf Of Frank DeethSent: Friday, 25 March 2016 21:07To: l29-list(at)matronics.com (l29-list(at)matronics.com)Subject: Re: Nitrogen Loss

I read once about an L-29 being operated in the UK where they disconnected the oxy system and plumbed those bottles into the pneumatic system, almost doubles the capacity if I recall...? Has anyone else looked at doing that?



FrankSent from my iPad

On Mar 26, 2016, at 4:20 AM, Bill Culberson <bculberson(at)staraviation.com (bculberson(at)staraviation.com)> wrote:

Quote:
Ultrasonic leak detector only works on the high pressure leaks (75-100 BAR), as it detects the specific audio signature of high pressure gas escaping. Canopy seals and brakes are at lower pressures and the soap and water test seems best.

I don’t use a Schrader valve but rather the original quarter turn valve but recently converted the N2 Cover to having a Schrader adapter “just in case”. My plane doesn’t leak much but discovered that with the cover changed and a good gasket the N2 cover that the N2 remains for weeks instead of days. Main check valve must be leaking.

I like the Hand valve at the tanks, what did you use? Pics?

Bill
N39DE
[url=] [/url]
From: owner-l29-list-server(at)matronics.com (owner-l29-list-server(at)matronics.com) [mailto:owner-l29-list-server(at)matronics.com (owner-l29-list-server(at)matronics.com)] On Behalf Of Jorgen NielsenSent: Friday, March 25, 2016 2:52 AMTo: l29-list(at)matronics.com (l29-list(at)matronics.com)Subject: RE: Nitrogen Loss

I also tried an ultrasonic leak detector, got a very expensive version on trial for a week from a specialty supplier. Could not find anything using it either. Soapy water is messy but seems to work best.

My air system is modified, with a hand valve installed close to the bottles. When I am done flying, I shut it off. Also nice if using the L29 to go somewhere, turn it off after landing, turn it back on before flight, no losses.

From: owner-l29-list-server(at)matronics.com (owner-l29-list-server(at)matronics.com) [mailto:owner-l29-list-server(at)matronics.com (owner-l29-list-server(at)matronics.com)] On Behalf Of Anthony RoyalSent: Friday, 25 March 2016 02:17To: l29-list(at)matronics.com (l29-list(at)matronics.com)Subject: Re: Nitrogen Loss

Hey guys,

Thanks for all your suggestions! John, I did the soapy water test on every fitting I could find all the way back to the fittings for the emergency bottle and beyond. ...tightened too. No Joy.



Bill, I think I did the top nut but missed the lower nut. I'll look at that next . Yeah, I'm 60 and a little too big to get into that small of quarters.



Hey Frank, thanks for the info too!



I'm also looking at disconnecting the the main pressurizing line line at the pressure reduction valve for the down stream items, after the nitrogen bottles, and capping off the line and then pressurizing the bottles. This should tell me if there is a leak anywhere upstream of the reduction valve in the main charging system. The emergency bottle holds pressure perfectly so no problems there.



According to the service manual, the minimum loss is 5 atm over 2 hours. So, I'm right on that limit at 2.5 atm per hour.



Thanks!

Tony









On Thursday, March 24, 2016 7:15 PM, John Cabrera <jetblast1(at)me.com (jetblast1(at)me.com)> wrote:


I don”t know if this is going to be of any help and some may laugh at me but i was chasing at leak in the rear canopy. Bought a fancy ultrasonic leak detector and could not find any leak. Finally decided to check with old fashion soapy water and a spray bottle. That worked.


John






Quote:
On Mar 23, 2016, at 8:22 AM, Anthony Royal <skyking76t(at)verizon.net (skyking76t(at)verizon.net)> wrote:


Guys, my L-29 has always held nitrogen for days without much loss of pressure. Other day I pressurized to 140 atm because of a long flight and day. Pressure bled off immediately from 140 to about 90 atm before I could get out of the hangar. And was totally empty the next day. I found several loose, original safety wired, connections not tight. Packing nut on the nitrogen purge valve was loose too. Tightened every fitting and thing I could find from nose to rear cockpit.



Now, if I pressurize to 50 atm, I will lose 30 atm in 12 hours. If I pressurize to 100 atm I lose 30 atm in 12 hours. Very consistent now. That's about 2.5 atm per hour. Any suggestions what else might cause such a consistent leak? Thinking maybe the pressure relief valve leaking? Check valve? Reading manuals and reviewing diagrams but thought maybe someone else may have run into this same problem and save a lot of time



Someone, in a post I can't find, suggested an ultrasonic tester of some sort to detect high pressure leaks. Does anyone know which one it was?



Also, looking for the glass lens for the taxi light. Rock must have hit mineand cracked it in half. Glued it back but would like to replacement. Also looking for connector to ARC EA-401A encoding altimeter.



Thanks for any info



Anthony






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Dawg



Joined: 19 May 2013
Posts: 355

PostPosted: Sat Mar 26, 2016 8:46 pm    Post subject: Nitrogen Loss Reply with quote

A schrader valve would prevent back flow.

Sent from my iPad

On Mar 27, 2016, at 08:08, Anthony Royal <skyking76t(at)verizon.net (skyking76t(at)verizon.net)> wrote:
Quote:
I would be interested too!
Found part of my leak problem.Removed the check valve that prevents nitrogen from the Nitro bottles from flowing back out of bottles. The flare on the check valve had a large burr,ridge on it. Not sure how that could have happened. Smoothed it out ( yes I know you can't really repair because you alter the angle) and used some aircraft grade sealer made for sealing a damaged flare and put back together for a test. Added 50 atm nitro last night and still had 20 atm left over 24 hours later and was stable. May leak at higher pressure but it is a start. Also removed the nitrogen tank purge/drain valve. Packing nut was still a little loose and it looked to have a little something on the sealing seat. When I first tried to tighten in the plane I got a significant increase in nitrogen pressure time. I'm working my way back toward the cockpit. Checked the 2 connections at the brake valve beside the stick. All seems to be very tight.
Anybody have a new or good used check valve?

On Saturday, March 26, 2016 2:32 AM, Bill Geipel <l129bs(at)gmail.com (l129bs(at)gmail.com)> wrote:



send description and pix.On Mar 25, 2016, at 20:36, Jean de Roubin <delfin29(at)me.com (delfin29(at)me.com)> wrote:
Quote:
I think the best way is an air compressor, working automatically at 20 bars and stopping at 50.
My, installed by the tzechs and approved by the factory is perfectly working since 15 years. No need of ground support.
Jean de RoubinEnvoyé de mon iPhone
Le 25 mars 2016 à 19:58, Frank Deeth <tr.9(at)westnet.com.au (tr.9(at)westnet.com.au)> a écrit :
Quote:
Thanks Jorgen!Sent from my iPhone
On 26 Mar 2016, at 6:50 AM, Jorgen Nielsen <jorgen.nielsen(at)mweb.co.za (jorgen.nielsen(at)mweb.co.za)> wrote:
Quote:
Mine is also done like that. I only posted half the story earlier, herewith then the full story J

I don’t use oxygen, so repurposed the tanks.

My oxygen tanks have a tap on them, close to the bottles, and a pressure gauge. The tap & gauge is situated in the nose compartment.
My normal air bottle (N2) also have a tap on them, and a gauge, also in the nose compartment.
So far, 2 separate systems.
After the taps, they are interconnected via a T, output goes to the air system.

Benefits:
Closing the valves means no leaks when she is standing.
Having the 2 systems that close means I can go away for a weekend with no ground support, or for example a 3 hop ferry I did a while back. At the destination, close the active system. For the next flight, pick a system and open valve. When the system is empty use the next one.

To fill, if its just a normal flight from home base, I open the valve for whichever system is in use, and fill normally. For extended flights, one can fill one system at a time, or open both and fill both, then close one.

So far, completely trouble free for a number of years.

I will have to take some pics when at the airport. I used spare hand operated valves, similar to the pressure release inside the cockpit. I never did the work myself, I have a Russian guy who does all my maintenance, I just dreamt it up and asked him to do it.

Another mod we did: my front / rear braking system has been reversed. I was once taxying with pax, and asked them to hold the brake while I did something. On release, when I took over, suddenly I had no brakes, and no steering obviously. We almost went farming. In normal ops, the rear brake is for the instructor, and held a certain way can disable the front cabin system. Not good for how we operate them privately.

Regards to all
Jorgen

From: owner-l29-list-server(at)matronics.com (owner-l29-list-server(at)matronics.com) [mailto:owner-l29-list-server(at)matronics.com (owner-l29-list-server(at)matronics.com)] On Behalf Of Frank DeethSent: Friday, 25 March 2016 21:07To: l29-list(at)matronics.com (l29-list(at)matronics.com)Subject: Re: L29-List: Nitrogen Loss

I read once about an L-29 being operated in the UK where they disconnected the oxy system and plumbed those bottles into the pneumatic system, almost doubles the capacity if I recall...? Has anyone else looked at doing that?



FrankSent from my iPad

On Mar 26, 2016, at 4:20 AM, Bill Culberson <bculberson(at)staraviation.com (bculberson(at)staraviation.com)> wrote:

Quote:
Ultrasonic leak detector only works on the high pressure leaks (75-100 BAR), as it detects the specific audio signature of high pressure gas escaping. Canopy seals and brakes are at lower pressures and the soap and water test seems best.

I don’t use a Schrader valve but rather the original quarter turn valve but recently converted the N2 Cover to having a Schrader adapter “just in case”. My plane doesn’t leak much but discovered that with the cover changed and a good gasket the N2 cover that the N2 remains for weeks instead of days. Main check valve must be leaking.

I like the Hand valve at the tanks, what did you use? Pics?

Bill
N39DE
[url=] [/url]
From: owner-l29-list-server(at)matronics.com (owner-l29-list-server(at)matronics.com) [mailto:owner-l29-list-server(at)matronics.com (owner-l29-list-server(at)matronics.com)] On Behalf Of Jorgen NielsenSent: Friday, March 25, 2016 2:52 AMTo: l29-list(at)matronics.com (l29-list(at)matronics.com)Subject: RE: Nitrogen Loss

I also tried an ultrasonic leak detector, got a very expensive version on trial for a week from a specialty supplier. Could not find anything using it either. Soapy water is messy but seems to work best.

My air system is modified, with a hand valve installed close to the bottles. When I am done flying, I shut it off. Also nice if using the L29 to go somewhere, turn it off after landing, turn it back on before flight, no losses.

From: owner-l29-list-server(at)matronics.com (owner-l29-list-server(at)matronics.com) [mailto:owner-l29-list-server(at)matronics.com (owner-l29-list-server(at)matronics.com)] On Behalf Of Anthony RoyalSent: Friday, 25 March 2016 02:17To: l29-list(at)matronics.com (l29-list(at)matronics.com)Subject: Re: Nitrogen Loss

Hey guys,

Thanks for all your suggestions! John, I did the soapy water test on every fitting I could find all the way back to the fittings for the emergency bottle and beyond. ...tightened too. No Joy.



Bill, I think I did the top nut but missed the lower nut. I'll look at that next . Yeah, I'm 60 and a little too big to get into that small of quarters.



Hey Frank, thanks for the info too!



I'm also looking at disconnecting the the main pressurizing line line at the pressure reduction valve for the down stream items, after the nitrogen bottles, and capping off the line and then pressurizing the bottles. This should tell me if there is a leak anywhere upstream of the reduction valve in the main charging system. The emergency bottle holds pressure perfectly so no problems there.



According to the service manual, the minimum loss is 5 atm over 2 hours. So, I'm right on that limit at 2.5 atm per hour.



Thanks!

Tony









On Thursday, March 24, 2016 7:15 PM, John Cabrera <jetblast1(at)me.com (jetblast1(at)me.com)> wrote:


I don”t know if this is going to be of any help and some may laugh at me but i was chasing at leak in the rear canopy. Bought a fancy ultrasonic leak detector and could not find any leak. Finally decided to check with old fashion soapy water and a spray bottle. That worked.


John






Quote:
On Mar 23, 2016, at 8:22 AM, Anthony Royal <skyking76t(at)verizon.net (skyking76t(at)verizon.net)> wrote:


Guys, my L-29 has always held nitrogen for days without much loss of pressure. Other day I pressurized to 140 atm because of a long flight and day. Pressure bled off immediately from 140 to about 90 atm before I could get out of the hangar. And was totally empty the next day. I found several loose, original safety wired, connections not tight. Packing nut on the nitrogen purge valve was loose too. Tightened every fitting and thing I could find from nose to rear cockpit.



Now, if I pressurize to 50 atm, I will lose 30 atm in 12 hours. If I pressurize to 100 atm I lose 30 atm in 12 hours. Very consistent now. That's about 2.5 atm per hour. Any suggestions what else might cause such a consistent leak? Thinking maybe the pressure relief valve leaking? Check valve? Reading manuals and reviewing diagrams but thought maybe someone else may have run into this same problem and save a lot of time



Someone, in a post I can't find, suggested an ultrasonic tester of some sort to detect high pressure leaks. Does anyone know which one it was?



Also, looking for the glass lens for the taxi light. Rock must have hit mineand cracked it in half. Glued it back but would like to replacement. Also looking for connector to ARC EA-401A encoding altimeter.



Thanks for any info



Anthony











- The Matronics L29-List Email Forum -
 

Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:

http://www.matronics.com/Navigator?L29-List

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Dawg
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View user's profile Send private message
skyking76t(at)verizon.net
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PostPosted: Sun Mar 27, 2016 4:27 pm    Post subject: Nitrogen Loss Reply with quote

Good idea Bill but if I can get the original part and bolt in, much easier and faster. I was lucky, found NOS part in CR.
Anthony

On Sunday, March 27, 2016 12:52 AM, Bill Geipel <l129bs(at)gmail.com> wrote:




A schrader valve would prevent back flow.Sent from my iPad
On Mar 27, 2016, at 08:08, Anthony Royal <skyking76t(at)verizon.net (skyking76t(at)verizon.net)> wrote:
Quote:
I would be interested too!

Found part of my leak problem.Removed the check valve that prevents nitrogen from the Nitro bottles from flowing back out of bottles. The flare on the check valve had a large burr,ridge on it. Not sure how that could have happened. Smoothed it out ( yes I know you can't really repair because you alter the angle) and used some aircraft grade sealer made for sealing a damaged flare and put back together for a test. Added 50 atm nitro last night and still had 20 atm left over 24 hours later and was stable. May leak at higher pressure but it is a start. Also removed the nitrogen tank purge/drain valve. Packing nut was still a little loose and it looked to have a little something on the sealing seat. When I first tried to tighten in the plane I got a significant increase in nitrogen pressure time. I'm working my way back toward the cockpit. Checked the 2 connections at the brake valve beside the stick. All seems to be very tight.

Anybody have a new or good used check valve?

On Saturday, March 26, 2016 2:32 AM, Bill Geipel <l129bs(at)gmail.com (l129bs(at)gmail.com)> wrote:
send description and pix.On Mar 25, 2016, at 20:36, Jean de Roubin <delfin29(at)me.com (delfin29(at)me.com)> wrote:
Quote:
I think the best way is an air compressor, working automatically at 20 bars and stopping at 50.
My, installed by the tzechs and approved by the factory is perfectly working since 15 years. No need of ground support.
Jean de RoubinEnvoyé de mon iPhone
Le 25 mars 2016 à 19:58, Frank Deeth <tr.9(at)westnet.com.au (tr.9(at)westnet.com.au)> a écrit :
Quote:
Thanks Jorgen!Sent from my iPhone
On 26 Mar 2016, at 6:50 AM, Jorgen Nielsen <jorgen.nielsen(at)mweb.co.za (jorgen.nielsen(at)mweb.co.za)> wrote:
Quote:
Mine is also done like that. I only posted half the story earlier, herewith then the full story J

I don’t use oxygen, so repurposed the tanks.

My oxygen tanks have a tap on them, close to the bottles, and a pressure gauge. The tap & gauge is situated in the nose compartment.
My normal air bottle (N2) also have a tap on them, and a gauge, also in the nose compartment.
So far, 2 separate systems.
After the taps, they are interconnected via a T, output goes to the air system.

Benefits:
Closing the valves means no leaks when she is standing.
Having the 2 systems that close means I can go away for a weekend with no ground support, or for example a 3 hop ferry I did a while back. At the destination, close the active system. For the next flight, pick a system and open valve. When the system is empty use the next one.

To fill, if its just a normal flight from home base, I open the valve for whichever system is in use, and fill normally. For extended flights, one can fill one system at a time, or open both and fill both, then close one.

So far, completely trouble free for a number of years.

I will have to take some pics when at the airport. I used spare hand operated valves, similar to the pressure release inside the cockpit. I never did the work myself, I have a Russian guy who does all my maintenance, I just dreamt it up and asked him to do it.

Another mod we did: my front / rear braking system has been reversed. I was once taxying with pax, and asked them to hold the brake while I did something. On release, when I took over, suddenly I had no brakes, and no steering obviously. We almost went farming. In normal ops, the rear brake is for the instructor, and held a certain way can disable the front cabin system. Not good for how we operate them privately.

Regards to all
Jorgen

From: owner-l29-list-server(at)matronics.com (owner-l29-list-server(at)matronics.com) [mailto:owner-l29-list-server(at)matronics.com (owner-l29-list-server(at)matronics.com)] On Behalf Of Frank DeethSent: Friday, 25 March 2016 21:07To: l29-list(at)matronics.com (l29-list(at)matronics.com)Subject: Re: Nitrogen Loss

I read once about an L-29 being operated in the UK where they disconnected the oxy system and plumbed those bottles into the pneumatic system, almost doubles the capacity if I recall...? Has anyone else looked at doing that?



FrankSent from my iPad

On Mar 26, 2016, at 4:20 AM, Bill Culberson <bculberson(at)staraviation.com (bculberson(at)staraviation.com)> wrote:

Quote:
Ultrasonic leak detector only works on the high pressure leaks (75-100 BAR), as it detects the specific audio signature of high pressure gas escaping. Canopy seals and brakes are at lower pressures and the soap and water test seems best.

I don’t use a Schrader valve but rather the original quarter turn valve but recently converted the N2 Cover to having a Schrader adapter “just in case”. My plane doesn’t leak much but discovered that with the cover changed and a good gasket the N2 cover that the N2 remains for weeks instead of days. Main check valve must be leaking.

I like the Hand valve at the tanks, what did you use? Pics?

Bill
N39DE
[url=] [/url]
From: owner-l29-list-server(at)matronics.com (owner-l29-list-server(at)matronics.com) [mailto:owner-l29-list-server(at)matronics.com (owner-l29-list-server(at)matronics.com)] On Behalf Of Jorgen NielsenSent: Friday, March 25, 2016 2:52 AMTo: l29-list(at)matronics.com (l29-list(at)matronics.com)Subject: RE: L29-List: Nitrogen Loss

I also tried an ultrasonic leak detector, got a very expensive version on trial for a week from a specialty supplier. Could not find anything using it either. Soapy water is messy but seems to work best.

My air system is modified, with a hand valve installed close to the bottles. When I am done flying, I shut it off. Also nice if using the L29 to go somewhere, turn it off after landing, turn it back on before flight, no losses.

From: owner-l29-list-server(at)matronics.com (owner-l29-list-server(at)matronics.com) [mailto:owner-l29-list-server(at)matronics.com (owner-l29-list-server(at)matronics.com)] On Behalf Of Anthony RoyalSent: Friday, 25 March 2016 02:17To: l29-list(at)matronics.com (l29-list(at)matronics.com)Subject: Re: Nitrogen Loss

Hey guys,

Thanks for all your suggestions! John, I did the soapy water test on every fitting I could find all the way back to the fittings for the emergency bottle and beyond. ...tightened too. No Joy.



Bill, I think I did the top nut but missed the lower nut. I'll look at that next . Yeah, I'm 60 and a little too big to get into that small of quarters.



Hey Frank, thanks for the info too!



I'm also looking at disconnecting the the main pressurizing line line at the pressure reduction valve for the down stream items, after the nitrogen bottles, and capping off the line and then pressurizing the bottles. This should tell me if there is a leak anywhere upstream of the reduction valve in the main charging system. The emergency bottle holds pressure perfectly so no problems there.



According to the service manual, the minimum loss is 5 atm over 2 hours. So, I'm right on that limit at 2.5 atm per hour.



Thanks!

Tony









On Thursday, March 24, 2016 7:15 PM, John Cabrera <jetblast1(at)me.com (jetblast1(at)me.com)> wrote:


I don”t know if this is going to be of any help and some may laugh at me but i was chasing at leak in the rear canopy. Bought a fancy ultrasonic leak detector and could not find any leak. Finally decided to check with old fashion soapy water and a spray bottle. That worked.


John






Quote:
On Mar 23, 2016, at 8:22 AM, Anthony Royal <skyking76t(at)verizon.net (skyking76t(at)verizon.net)> wrote:


Guys, my L-29 has always held nitrogen for days without much loss of pressure. Other day I pressurized to 140 atm because of a long flight and day. Pressure bled off immediately from 140 to about 90 atm before I could get out of the hangar. And was totally empty the next day. I found several loose, original safety wired, connections not tight. Packing nut on the nitrogen purge valve was loose too. Tightened every fitting and thing I could find from nose to rear cockpit.



Now, if I pressurize to 50 atm, I will lose 30 atm in 12 hours. If I pressurize to 100 atm I lose 30 atm in 12 hours. Very consistent now. That's about 2.5 atm per hour. Any suggestions what else might cause such a consistent leak? Thinking maybe the pressure relief valve leaking? Check valve? Reading manuals and reviewing diagrams but thought maybe someone else may have run into this same problem and save a lot of time



Someone, in a post I can't find, suggested an ultrasonic tester of some sort to detect high pressure leaks. Does anyone know which one it was?



Also, looking for the glass lens for the taxi light. Rock must have hit mineand cracked it in half. Glued it back but would like to replacement. Also looking for connector to ARC EA-401A encoding altimeter.



Thanks for any info



Anthony











- The Matronics L29-List Email Forum -
 

Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:

http://www.matronics.com/Navigator?L29-List
Back to top
ershire



Joined: 12 Jul 2011
Posts: 53

PostPosted: Thu Mar 31, 2016 10:12 am    Post subject: Nitrogen Loss Reply with quote

Tony, can the canopy seals be patched like a bicycle tube?

Jon
On Mar 27, 2016 8:30 PM, "Anthony Royal" <skyking76t(at)verizon.net> wrote:

[quote] Good idea Bill but if I can get the original part and bolt in, much easier
and faster. I was lucky, found NOS part in CR.

Anthony
On Sunday, March 27, 2016 12:52 AM, Bill Geipel <l129bs(at)gmail.com> wrote:
A schrader valve would prevent back flow.

Sent from my iPad

On Mar 27, 2016, at 08:08, Anthony Royal <skyking76t(at)verizon.net> wrote:

I would be interested too!

Found part of my leak problem.Removed the check valve that prevents
nitrogen from the Nitro bottles from flowing back out of bottles. The flare
on the check valve had a large burr,ridge on it. Not sure how that could
have happened. Smoothed it out ( yes I know you can't really repair because
you alter the angle) and used some aircraft grade sealer made for sealing a
damaged flare and put back together for a test. Added 50 atm nitro last
night and still had 20 atm left over 24 hours later and was stable. May
leak at higher pressure but it is a start. Also removed the nitrogen tank
purge/drain valve. Packing nut was still a little loose and it looked to
have a little something on the sealing seat. When I first tried to tighten
in the plane I got a significant increase in nitrogen pressure time. I'm
working my way back toward the cockpit. Checked the 2 connections at the
brake valve beside the stick. All seems to be very tight.

Anybody have a new or good used check valve?
On Saturday, March 26, 2016 2:32 AM, Bill Geipel <l129bs(at)gmail.com> wrote:
send description and pix.

On Mar 25, 2016, at 20:36, Jean de Roubin <delfin29(at)me.com> wrote:

I think the best way is an air compressor, working automatically at 20
bars and stopping at 50.
My, installed by the tzechs and approved by the factory is perfectly
working since 15 years. No need of ground support.
Jean de Roubin

Envoyé de mon iPhone

Le 25 mars 2016 à 19:58, Frank Deeth <tr.9(at)westnet.com.au> a écrit :

Thanks Jorgen!

Sent from my iPhone

On 26 Mar 2016, at 6:50 AM, Jorgen Nielsen <jorgen.nielsen(at)mweb.co.za>
wrote:

Mine is also done like that. I only posted half the story earlier,
herewith then the full story J

I don’t use oxygen, so repurposed the tanks.

My oxygen tanks have a tap on them, close to the bottles, and a pressure
gauge. The tap & gauge is situated in the nose compartment.
My normal air bottle (N2) also have a tap on them, and a gauge, also in
the nose compartment.
So far, 2 separate systems.
After the taps, they are interconnected via a T, output goes to the air
system.

Benefits:
Closing the valves means no leaks when she is standing.
Having the 2 systems that close means I can go away for a weekend with no
ground support, or for example a 3 hop ferry I did a while back. At the
destination, close the active system. For the next flight, pick a system
and open valve. When the system is empty use the next one.

To fill, if its just a normal flight from home base, I open the valve for
whichever system is in use, and fill normally. For extended flights, one
can fill one system at a time, or open both and fill both, then close one


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