correct torque for AN fitting

Sarge81 said: "If you follow these torque values, it will probly leak" These values are derived from an Air Force aircraft Tech Manual Hope this helps! Sarge

now that we know what the "official" values are.. how would you torque a line like this. are there bar type torque wrenchs with a crescent wrench jaw. ive always used a crow's foot wrench to do this.. but technically its not to accurate as the multiple angles involved change the true torque.

just my curiousity at work..

|UPDATED|7/19/2004 10:48:41 AM (AZT)|/UPDATED|

We use a crows foot on a torque wrench. Even though it is a little offset, the "error" is so minor it isn't worth figuring out the difference.
Also I'd like to add, is that in the event that you cannot use a torque wrench due to confined spaces. You have to use a little common sense on tightening these fittings down.
Most of the smaller lines (-2 to -6) only need about an 1/8 to a 1/4 turn to snug it down after it stops threading easily by finger. You can crack a B-nut or a Flare if you really "smoke" them down. And be sure to use a back up wrench to hold the opposing fitting or bulkhead from turning.
Hope this helps!
Sarge

Ok, I found some information in the Aeroquip Catalog that was online at this link. Its on page 51 and give a detailed description of how to torque down fittings and their torque ratings.

http://www.aeroquip.com/media/A-SPPE-MC0001-E.pdf

Hope that helps

I read this and it suggests that if you dont have a torque wrench use hand tight plus 1/4 turn..

which is where we started..

but the fires of my curiousity have now been quenched.

Nice find there Matt.
I see that Aeroquip torque values are a little different than U.S. Air Force standards, and we use a lot of Aeroquip hoses and fittings on our planes. Go figure!

But, all in all. The 1/8 to 1/4 turn will put you in the "ballpark." And if you can't stop a leak or a seep, then you have either a bad fitting or bad flare in the hose end.

Remember to ALWAY'S use a backup wrench to hold the fitting/union still as you tighten down your hose. That prevents mis-torqing, or ripping threads out of the item your attaching to, and it also prevents the "clocking" of say a 45/90 degree elbow fitting from changing.

Any more questions feel free to ask. I've been working with these fittings and hoses for about 8 yrs. (I work on "KC-135R's"= Boeing 707's in the NY Air Nat.Guard for those of you that didn't know.)

Sarge

|UPDATED|7/23/2004 6:14:39 AM (AZT)|/UPDATED|

Sarge81 said: Nice find there Matt. I see that Aeroquip torque values are a little different than U.S. Air Force standards, and we use a lot of Aeroquip hoses and fittings on our planes. Go figure!

yeah but some of those TM's were written by crackheads..

It took three TM corrections to get the wiring diagram for the starter circuit on the LVS correct. Seemed like the guy writing the manual had never seen the vehicle.

Sarge81 said: Any more questions feel free to ask. I've been working with these fittings and hoses for about 8 yrs. (I work on "KC-135R's"= Boeing 707's in the NY Air Nat.Guard for those of you that didn't know.) Sarge

Thanks a bunch, Sarge, you're a class act.

JR

Thank you for the compliment JR!

I enjoy helping out when I can, just as the many other folks here do.
Take Care,
Sarge

For all the years I have worked with them, I never had a spec. Thanks Sarge, good work.