An interesting type of hose fitting

The hole in the lower nut is for a nail that is hammered into a common groove machined in the nut and the elbow piece as well and that keeps the unit joined. Look at the Yak air or oil hose parts that show the same idea. I was very curious to see what keeps it all together so took a hacksaw to learn this. Afterwards I had to copy the elbow from stainless steel for exchanging the set of hoses in the 10 year period but did not get our own connectors back. They just sent overhauled completed sets of hoses back. Basically one could do these hose changes without any special tools as it is all just screwed together, no press required, but then you have no papers for the ARC. Maybe that will change with ELA 2. The swivel joint has most probably some o-ring in it like in many hydraulic joints for static pressure conditions. There is no turning action when once mounted on the machine/aircraft. Vic

Well, about the o-ring, I don´t know your items and am not sure where exactly the motion is. Very often o-rings are used for axial sealing so some flat face in there could be present but one can only find out by taking that to pieces for learning . At least this is a way to overcome these taper thread elbows that never really end in a position that you like to have. Vic