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Fuel hose torque requirements

EastCoastFlyer

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How do you properly torque the fittings on the end of the fuel and oil hoses? Is it a torque value or a "hand tighten and then turn a specific amount more"? Where do I find these values? I can't find a reference in the construction manual or the Rotax manuals....
 
That’s a good question to ask. Aeroquip has a nice explanation right here:
https://www.vansaircraft.com/pdf/Torque_Spec_Aluminum_Fittings.pdf

The easiest way to remember, and the one I use, is the Alternate 1/4 turn method. They don’t mention oiling the threads, but it’s good insurance against galling.
1. Oil the threads with a couple drops of lightweight machine oil (air tool oil is perfect)
2. Hand tighten
3. Turn 1/4 turn with a wrench.
 
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EastCoast,

The info you are looking for is in section 5-14. There you will see the torques for the aluminum fittings listed. There is also a section in the red Aircraft Standards handbook that comes with the kit ... don't have the book with me so can't point you to the section.

You will want to pick up a set of crowsfoot wrenches for torquing the fittings with a torque wrench. Below is a link to my blog that covers using crowsfoot wrenches to torque the fittings.
http://www.dogaviation.com/2014/01/calculating-torque-values-for-fuel.html

Happy building,
 
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AC43-13, table 9-2. Show min and max for steel tubing, so use the upper limit for stainless.
Flats method works well also.

Tom
 
From 5.14 ALUMINUM TUBING

From 5.14 ALUMINUM TUBING

Slide the AN818 nut over the far end of the tube and engage the threads on the AN fitting. Tighten to the specified torque. You should have a Standard Aircraft Handbook with the torque tables for these things. (assuming aluminum fittings, for 1/4 tubing it is 40-65 inch-pounds, for 3/8 tubing it is 75-125 inch-pounds.) Later, you can leak test the system.
 
Guys:
Sorry to dig up an old thread, but I just happened to be reviewing 5.14 tonight with the 75-125 inch pound reference for 3/8" tubing (-6) when I noticed something.

That doesn't match 43.15

noname.jpg


... which shows something along the lines of 120 for -6 AN818 nut.

So obviously Van is referencing something that is apparently in the Standard Handbook (why can't I find my copy), but what am I missing as to why it doesn't match 43.15?

Is it because 43.15 is geared toward the airline maintenance folks and the alloy is 5052 (because god forbid the government should recognize we use 3003)?

I'll hang up and listen.
 
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