Aeroquip Torque Chart vs. everything else

[HighSchoolBuilders]

Hi all,

I came to the part where I have to torque all the fuel and brake AN fittings. I have been researching on the web as well as all the references out there, they all have different values and I am lost as to follow which to follow.

First, I looked at Van's Manual, under section 5, 5P (pg. 5-7), it says:
1/4" tubing it's 40-65 in-lb.
3/8" tubing it's 75-125 in-lb

Then I look further on Van's website and found a PDF by Aeroquip, and it clearly stated Torque Specification for Al fittings is:
-4 Nut size = 100-140 in-lb
-6 Nut size = 150-195 in-lb

On top of that, it has this Alternate method and when I compare using this method and a torque wrench, it seems like the two do not yield similar results. If I use the alternate method, it appears to be under torque because I can go much further with a torque wrench before reaching the value.

Then on the web, there is the army Chinook helicopter repair manual, which stated
-4 Al hose = 50-65 in-lb
-6 Al hose = 100-125 in-lb

And just to confuse me even further, some values are for lubricated thread and some didn't say the value is lubricated or not.

Can anyone tell me if I am missing something here because I don't think there should be so much discrepancies from difference sources.

Can anyone tells me if they have leak or damage with the value you went with?

Any feedback or suggestion is greatly appreciated!
Cheers!
Hank

[rzbill]

You are comparing apples and oranges.
Torque specifications change depending on whether it is tubing (and what metal is in the tubing like 3003 or 5002) or whether it is a hose assembly with machined internal seal faces. You must know what the chart is refering to.

If you are still confused, comunicate with Vans directly.

[Walt]

Van's numbers and Chinook numbers are very close, with the max being the same. Either of these will be fine for aluminum tube.

I suspect the Aeroquip numbers are for steel tubing/fittings.

[Tandem46]

Originally Posted by HighSchoolBuilders

I came to the part where I have to torque all the fuel and brake AN fittings.

Hank, as rzbill said, there is a difference between aluminum tubing with B-nuts and aero quip hose fittings.

[flion]

And don't even get us started on NPT torque. Use the lower torque on the aluminum tube you get from Vans. It's a softer alloy and you don't want to torque the flare off of it. If you replace the tubing, as has been suggested by others (search for threads on the topic), then you can use a higher torque. For hoses or unique equipment, follow the manufacturer's recommendations (the NPT fittings for my FT-60 fuel flow transducer had quite specific instructions). Flare fittings are never lubricated; NPT fittings should have some kind of appropriate sealant. So, unlike bolts, there should be no lubed/unlubed confusion.

[HighSchoolBuilders]

Arrrrrggg! This is not cool, why would Van's put a chart with an incorrect value for the hardware they provided?! Unfortunately, I went with the Aeroquip figures, torque all the -6 fittings to 160 in/lbs.

Is changing all the hoses inevitable? I spent ages on those hoses, not cool!

Thanks guys!

[dhmoose]

In the 2.5 years I've been building, this topic has come up at least 10 times and each time, it is clear that confusion reigns supreme. I still get confused by it! The frustrating part for a new builder is that you read how critically important it is not to under torque or over torque, not to crack the aluminum, not to damage the NPT fittings, not to crack the casing the fitting is going into, not to screw up or else a fire may result (or a brake failure), not to seal this...and always seal that. So the new builder says, "ok, I get it! I'll make sure I'm doing it right!". Then, the new builder realizes that nobody seems to know what is "right", as evidenced by the responses in this thread and so many others. Arrggg.

Shouldn't someone (Vans?) produce an authoritative summary of how to deal with B nuts, NPT fittings (steel and aluminum), flared fittings, etc?

And yes, I've seen Vans document, Aeroquips document, 43.13, AFP info, etc. I just think there should be a one page summary of definitive information. We've been tightening these **** things for years...why does confusion still exist? Ok, I'm done venting. Btw, a great response would be a one page summary of it all

[WenEng]

Here is example of options people might choose. You are looking for a simple answer to a multiple choice question. I share your pain.


http://home.earthlink.net/~delaero/delpage3.htm

[HighSchoolBuilders]

Thanks guys, I now understand, but it's a bit too late. I think there are info out there but a lot of them are assuming we know what we're doing....which in my case, I am completely new and have no idea.

Thanks for all the reply!

[az_gila]

Originally Posted by tobinbasford

Definitely aluminum.
http://www.vansaircraft.com/pdf/Torq...m_Fittings.pdf

No... look at the pictures. It is for aluminum fittings and aluminum hose ends or fittings. Not to flared tubing....