Is there a gospel side to place the silicon O rings on any weldless bulkhead fitting?
I find that I seen them on the inside, and on the outside of the vessels?
I would figure they would be best on the inside. #1 to stop any liquid to make it to the outside. #2 Not to burn, melt or char them from flame.
I have also seen bulkhead "Instructions" on websites telling you where to place it, And then in pictures on the same website, showing it the opposite side. ???
I'm setting up a keggle now.
Pictures are a great tool to me, and are worth a 1000 words !