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Problem with UAT tank. how to correctly set up fuel system

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Problem with UAT tank. how to correctly set up fuel system

Old 02-07-2013, 02:26 PM
  #26  
marc s
 
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Default RE: Problem with UAT tank. how to correctly set up fuel system

they operate under suction
Gary they do actually operate under both, during filling they are under pressure and often this process actually leads to main tank damage due to the pressure of the fuel delivery verses the size of the venting bores. The CAT products have a smaller bore fill barb to help reduce this pressure situation.

Naturally its easier to test under pressure and this process is to determine the CAT is 100% airtight, the assumption is that under suction the result is the same.

marcs
Old 02-07-2013, 03:01 PM
  #27  
rcand
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Default RE: Problem with UAT tank. how to correctly set up fuel system


ORIGINAL: marc s

I friend of mine had your type bubble trap in an airplane that constantly would flame out due to air.
I would be interested to understand why this happened, as in essence the method of what my CAT product does and the BVM UAT are very similar so why one works and the other does not is somewhat baffling!

The CAT which is a product designed to help prevent air entering the fuel feed to the turbine (via the pump) has been successfully used for the last 12 months on the NASA/Boeing joint project - X48C. The units were tested to the limits before they were approved for use in a multi-million $ project and I am certain they would have not used them if there was a chance they were no good!

Whilst there is always a chance products do not work for all there are some real important things that must be done to ensure any fuel related products stand a good chance of delivering 100% reliability -

USE QUALITY CORRECT BORE TUBING
SECURITY WIRE ALL FITTINGS - DO NOT USE CABLE TIES (as the name implies they are for use with cable not fuel line)
AVOID EXTRA FILTERS IN LINE, VALVES OR RESTRICTIONS (these will restrict fuel flow and that's not a good thing)
MOUNT CORRECTLY (as per manufacturers spec)
USE CORRECT FITTINGS TO SEAL PIPES AND FITTINGS

I personally make and test EVERY CAT to 30-40psi, which is more than the pressure in most car tyres so unless the unit has been damaged there is NO way it will leak air, if air is getting into it then its coming from a connection elsewhere on the fuel system (or via cavitation)

If you wish to check some of the test data on a range of UAT products including the CAT have a look at this very in depth article about 'all things' related to setting up a reliable full system..

[link]http://www.ultimate-jets.net/blogs/fuel-system-for-jets-considerations[/link]

marcs

I can't explain why but after several months of flameouts on almost every flight, the problem stopped after changing it. All cars are made to start, run and get you somewhere. Some manufacturers cars are less reliable and need repairs more often. Some you can drive and do routine maintenance and never have a significant breakdown, You can try your luck on a chevy, or go for a Lexus. I'll take the Lexus.
Old 02-07-2013, 05:23 PM
  #28  
Gary Arthur
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Default RE: Problem with UAT tank. how to correctly set up fuel system


ORIGINAL: marc s

they operate under suction
Gary they do actually operate under both, during filling they are under pressure and often this process actually leads to main tank damage due to the pressure of the fuel delivery verses the size of the venting bores. The CAT products have a smaller bore fill barb to help reduce this pressure situation.

Naturally its easier to test under pressure and this process is to determine the CAT is 100% airtight, the assumption is that under suction the result is the same.

marcs
Very good point. Makes a lot of sense. Thanks.
Old 02-07-2013, 09:10 PM
  #29  
Bob Toilet
 
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Default RE: Problem with UAT tank. how to correctly set up fuel system

A Lexus is just a high gloss TOYOTA





ORIGINAL: rcand


ORIGINAL: marc s

I friend of mine had your type bubble trap in an airplane that constantly would flame out due to air.
I would be interested to understand why this happened, as in essence the method of what my CAT product does and the BVM UAT are very similar so why one works and the other does not is somewhat baffling!

The CAT which is a product designed to help prevent air entering the fuel feed to the turbine (via the pump) has been successfully used for the last 12 months on the NASA/Boeing joint project - X48C. The units were tested to the limits before they were approved for use in a multi-million $ project and I am certain they would have not used them if there was a chance they were no good!

Whilst there is always a chance products do not work for all there are some real important things that must be done to ensure any fuel related products stand a good chance of delivering 100% reliability -

USE QUALITY CORRECT BORE TUBING
SECURITY WIRE ALL FITTINGS - DO NOT USE CABLE TIES (as the name implies they are for use with cable not fuel line)
AVOID EXTRA FILTERS IN LINE, VALVES OR RESTRICTIONS (these will restrict fuel flow and that's not a good thing)
MOUNT CORRECTLY (as per manufacturers spec)
USE CORRECT FITTINGS TO SEAL PIPES AND FITTINGS

I personally make and test EVERY CAT to 30-40psi, which is more than the pressure in most car tyres so unless the unit has been damaged there is NO way it will leak air, if air is getting into it then its coming from a connection elsewhere on the fuel system (or via cavitation)

If you wish to check some of the test data on a range of UAT products including the CAT have a look at this very in depth article about 'all things' related to setting up a reliable full system..

[link]http://www.ultimate-jets.net/blogs/fuel-system-for-jets-considerations[/link]

marcs

I can't explain why but after several months of flameouts on almost every flight, the problem stopped after changing it. All cars are made to start, run and get you somewhere. Some manufacturers cars are less reliable and need repairs more often. Some you can drive and do routine maintenance and never have a significant breakdown, You can try your luck on a chevy, or go for a Lexus. I'll take the Lexus.
Old 02-08-2013, 04:37 AM
  #30  
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Default RE: Problem with UAT tank. how to correctly set up fuel system

Hi Ulrich

Glad you sorted it out...

I use Festo manual valve for safety shut-off in the pressure side. Suction side is as direct and short as possible. Even if Festo says that they can operate under a small amount of vaccum, remember theose were designed to operate with air and not jet fuel.

To guarantee that the system can operate unnder vacuum, you should use Festo tube in the pressure side or other PU type tube. What I see ususally, are tygon connected to PU, than a Shut-off valve, again PU tube and tygon, and so on. GO short and direct, that´s it. With time, if you have an old or improper tube in the suction side, you get a reasonable chance for air to get in, specially with big engines at full throtle...

On the pressure side, in the event of a manual shut-off and pump still working, don't worry because the pump won't generate enough pressure to blow things up. The worst scenario after a reasonable time might be a burn motor. It wouldn't happen because ECU would shut pump off

To each, it's own....

Regards

Nuno
Old 02-08-2013, 11:20 AM
  #31  
uixkes
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Default RE: Problem with UAT tank. how to correctly set up fuel system

Hi Nuno

On the pressure side I am using the clear tube provided by JetsMunt. I used nearly all the supplied tubing as the pump is quite a long distance from the turbine. The rest I used on the suction side from the pump to the filter, which is also provided by JetsMunt. The manual states that the filter should be placed as close as possible to the pump. The tubing on the suction side should be as short as possible, which I tried to achieve with my setup.

My third test run went well without any problems, so I assume that I can leave my setup as it is.

I guess the real test will be the maiden but I am sure everything will be OK.

Ulrich
Old 02-08-2013, 12:59 PM
  #32  
rcand
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Default RE: Problem with UAT tank. how to correctly set up fuel system


ORIGINAL: Bob Toilet

A Lexus is just a high gloss TOYOTA





ORIGINAL: rcand


ORIGINAL: marc s

I friend of mine had your type bubble trap in an airplane that constantly would flame out due to air.
I would be interested to understand why this happened, as in essence the method of what my CAT product does and the BVM UAT are very similar so why one works and the other does not is somewhat baffling!

The CAT which is a product designed to help prevent air entering the fuel feed to the turbine (via the pump) has been successfully used for the last 12 months on the NASA/Boeing joint project - X48C. The units were tested to the limits before they were approved for use in a multi-million $ project and I am certain they would have not used them if there was a chance they were no good!

Whilst there is always a chance products do not work for all there are some real important things that must be done to ensure any fuel related products stand a good chance of delivering 100% reliability -

USE QUALITY CORRECT BORE TUBING
SECURITY WIRE ALL FITTINGS - DO NOT USE CABLE TIES (as the name implies they are for use with cable not fuel line)
AVOID EXTRA FILTERS IN LINE, VALVES OR RESTRICTIONS (these will restrict fuel flow and that's not a good thing)
MOUNT CORRECTLY (as per manufacturers spec)
USE CORRECT FITTINGS TO SEAL PIPES AND FITTINGS

I personally make and test EVERY CAT to 30-40psi, which is more than the pressure in most car tyres so unless the unit has been damaged there is NO way it will leak air, if air is getting into it then its coming from a connection elsewhere on the fuel system (or via cavitation)

If you wish to check some of the test data on a range of UAT products including the CAT have a look at this very in depth article about 'all things' related to setting up a reliable full system..

[link]http://www.ultimate-jets.net/blogs/fuel-system-for-jets-considerations[/link]

marcs

I can't explain why but after several months of flameouts on almost every flight, the problem stopped after changing it. All cars are made to start, run and get you somewhere. Some manufacturers cars are less reliable and need repairs more often. Some you can drive and do routine maintenance and never have a significant breakdown, You can try your luck on a chevy, or go for a Lexus. I'll take the Lexus.
I've seen as many Mercedes broken down on the roadside as the cheap cars too.

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