Fuel Tank Vent Lines

OK, more questions. I bent-up my vent lines and all went well. On Drawing 36A, Detail D-D shows the vent line fitting through the F-902 bulkhead. It looks like there's a washer on the inside of the bulkhead, but it's not called-out in the diagram. Should there be a washer in there?

Thanks again,

Tom

OK

Maybe a picture will help.
I have several large (1") flat washers that appear to go with the AN fittings for the vent line. In the picture below it looks like there may be a washer behind that AN-924 nut. Thoughts?

AN bulkhead fittings

On AN bulkhead fittings, there is a little tiny shoulder in the inside of the body hex where it goes through a bulkhead, then a gap, then the threads for the nut. If you run the nut up to the hex body, the tiny shoulder is larger than the thread OD, so the nut won't actually tighten up to be flush with the hex body. So on a thin bulkhead, you could tighten up the nut and instead of it bottoming on the bulkhead, it could bottom on the tiny shoulder. So in cases where the bulkhead fitting goes through a thin bulkhead (like your example) I just use whatever AN960 washer goes over the threads so the nut bottoms out on the bulkhead/washer.

F-9101

Tom,
I just chedked mine and that hidden line is the f-9101 where it doubles on the buikhead.

It is cutoff in the bottom of the drawing so it looks like washer sized.

Happy plumbing!