That and conical seals to help seal worn flares, but that’s on the flare, not the thread. People ALWAYS overtighten AN fittings…STOP! You tighten them 1-2 hex flats last hand tight…per the BOEING MM’s.
That and conical seals to help seal worn flares, but that’s on the flare, not the thread. People ALWAYS overtighten AN fittings…STOP! You tighten them 1-2 hex flats last hand tight…per the BOEING MM’s.