Thread sealant and hydraulic fittings

[millrat]

Just wondering how many use some type of sealant on flare fittings(37/45 deg), and why?

[Conrad1]

Never use anything in JIC or flares. They are designed for a compression leak free seal as long as they are the same mating angle 37-37 and 45-45 and are clean and burr free. I only used t tape once on a JIC threads only as a thread locker because it kept shaking loose. Only temporarily till we could change out both fittings.

We use everything 37 degrees from -2 to -24 sized fittings regularily without any leak trouble all the way up to 10,000psi.