Those various wavey shape washers thingies, reminded my coming across a scuba manual/power inflator that had compression fitting.
The washer as it got flattened out, would expand and supposed to grab the two pipe parts together.
It was a hot day in Los Angles, and the dive boat I was on had us waiting a while as other boats tied up to the mooring to scuba dive a hundred foot deep ship wreak.
I was going down the anchor line and at about 40ft the connection came apart from the power inflator on my drysuit I was wearing.
I did maybe what people should not do, that is continue and not abort the dive.
I gave an OK to my dive buddy and we did dive the wreak. The thing I was concerned about was did I loose the wavey shape washer.
It still was attached to one of the two pipe parts, as I got on board the boat with a couple of quarts of sea water in each of the legs on the drysuit.
The clamp fitting at the other end of this elbow shape pipe attaching to the drysuit, I swapped the different fittings to there prior respective places.
The increased angular stress, where the elbow pipe has entry to the suit, works better using a clamp fitting. I am not sure why compression fitting have there use as it comes apart easier than a clamp fitting.
I also was diving with a buoyancy compensator vest at the time as I always do, so I did not have to ditch weights to get to the surface. That drysuit and others I have used are not thin shell type material. The neoprene still helps keep you warm even when drysuit undergarments get soaking wet.
Interesting these similar kind of parts. I heard in tight spaces compression fitting can be slimmer and that is an advantage.