Need help tightening AN818 tubing nut

I had a link to how to torque an AN818 tubing nut, but can't find it.
can anyone tell me the correct procedure or send me in the right direction.

AC 43.13-1B

You will find what you need in Chapter 9 of the FAA's AC 43.14-1B "Acceptable Methods, Techniques and Practices for Aircraft Repair". Look on pages 9-18 and 9-19. This document is a "must have" for any RV builder. You can download it for free, chapter by chapter [14] from the FAA web site linked below.

http://www.airweb.faa.gov/Regulator...99C827DB9BAAC81B86256B4500596C4E?OpenDocument

To prevent damage to the AN818 B nut, use a tubing wrench similar to the ones linked below.

http://www.sears.com/craftsman-5-pc-flare-nut-wrench-set-standard/p-00942012000P

If you are unsure of how tight the nut should be, refer to the torque table on page 9-19. You can use a torque wrench with crowfoot tubing wrenches like the ones linked below. An extension may be used to keep the torque wrench clear of the tubing.

http://www.sears.com/shc/s/p_10153_...03j&srccode=cii_9324560&cpncode=35-34725579-2

Charlie

b nut torque

I have a Standard Aircraft Handbook that has torques, descriptions and all kinds of other neat hardware related stuff. The torques I'm thinking you are looking for are maybe the fuel tank vent, 1/4" tubing od, and the fuel line, 3/8" tubing od.
The torques for aluminum are 40-65 "lbs and 75 to 125 "lbs.
Do yourself a favor and get some sort of Standards book, they're priceless.
good luck
danny

Thanks everyone for the help. I also found the chart I was looking for.
Aeroquip puts it out. If you can't get the correct torque wrench, they give two alternate methods. #1 1. tighten the nut by hand until it bottoms the seats. 2. Using a marker, draw a line lengthwise on the nut and extend it to the adapter. 3. Using a wrench, rotate the nut to tighten. Turn the nut the amount shown on the chart. size-04---1 1/2 to 1 3/4 hex flats rotations. size-06 1 to 1 1/2 hex flats rotations. #2 The second method of tightening is very simple and easy to remember. Bring the nut to hand tight and then rotate a quarter turn. This applies to all sizes. Mark the fitting as indicated in the flat method to confirm the quarter turn. Aeroquip puts the chart out and also gives the torque values when you can get a wrench on them.
Thanks Again

depends on material

Tested torque compared to degree of turn from hand tight and they were different from Vans tube to the 5052 line to the Bonaco hoses. If I used the 1/4 turn method on the Bonaco, I would have more than doubled the torque recommended from Bonaco. I torqued fittings on the bench to determine degree of turn as a platform and then during install ( if torque wrench was not possible to use) used the degree of turn based on what I calculated on bench. Most accurate is to use torque method when possible.

tigthening torque

Just to clarify, the installation torque for a aluminum fitting on the end of a hose is not the same as the installation torque for an AN818 nut and collar on a flared aluminum tube. The data in the Aeroquip catalogue likely applies to aluminum hose fittings. From the Aeroquip catalogue the installation torque for a -4 aluminum fitting is 100 to 140 in-lbs. From AC 43.13 the torque for an -4 AN818 nut on aluminum tubing is 50 to 65 in-lbs. If the higher torque is used on tubing it is very likely the collar will extrude through the flare in the tubing which will produce a poor connection with associated leaks or complete tubing failure. This is particularly true if you are using the soft 3003 alloy tubing supplied by Van's.

Thanks all, I have the acceptable methods, techniques, and practices book. Kevin, it didn't dawn on me, till you mentioned it, that the Aeroquip figures were for their hoses.