Anti rotation bracket on vent line fitting

[bmellis11]

I have never worked with fuel tank fittings before so this may sound like a dumb question. I'm building an RV-8. The fuel pickup tube fitting is supposed to have an anti rotation bracket, but the plans do not indicate one for the vent line. I read somewhere that rotation is not as much of a concern when the fixed nut part of the fitting is outside of the tank (as it is on the vent line fitting) because you can hold it in place with a second wrench when tightening down the line. Even if that's true, would it be safer to have an anti rotation bracket on the vent line fitting just in case so the seal doesn't get broken at some point?

 

[Ralph Inkster]

I see the later RV14 & 10 kits use an anti-rotation plate on their vent fittings, part# T-1010.

 

[Scott Hersha]

The vent line on my RV6 is a 90* bulkhead elbow with the 90* elbow end being on the outside of the tank. That means the nut is on the inside. The fitting is installed with generous amounts of proseal both in the opening and completely covering the tightened nut on the inside. I think there is a large area washer on the outside to reinforce the opening and also gets plenty of proseal. It couldn’t turn if you wanted it to.

 

[rvbuilder2002]

On the RVs that have a 90° fitting on the tank for attachment of the external vent line, when you are tightening the line you were not inducing a rotation on the fitting installed in the tank, so no anti-rotation component is needed
When the vent is connecting to a straight fitting on the tank, tightening, the external line is inducing a rotation on the fitting, and then an anti-rotation component is utilized