Sal
+1y
As long as you don't over tighten the fittings, the flares should remain close to spec. The key is not mixing AN and JIC fittings. They are both 37° flare fittings but the sealing surfaces and thread thickness are in separate classes with material strengths. There are also 45° SAE fittings and these should NOT be thrown into the mix.. either make all of your fittings 45° SAE's or don't use them at all as to not have a chance to mix them up. Generally speaking, go with 37° JIC fittings as a standard as that is what is commonly available. Steel fittings are are a standard with oil based hydraulic setups seeing as it's very high strength and there is no worry of it rusting like with pneumatic setups. Just my $.02 I could see an o-ring boss on the flare helping to seal but not if that fitting were to be commonly cracked (or completely) open(ed). The more wear that o-ring were to see, the more likely it will be to fail. If this is a fitting you may rarely loosen up, I could see them holding up over time. Keep in mind, the more things there are to go wrong, the more things there are to fix when the shit goes down. I haven't looked into them much, any links for info on them?