Propane regulator?

It’s threaded

Oh, and if tightening a flare fitting use 2 wrentches to get it to seat.

Depends on the fitting. Flare fittings get nothing, they flare out and self seat. Adding tape or goop can cause them not to seat properly and leak. Other conections need tape or goop. Goop os probably better, aka pipe dope. None of the people that install gas pipes in my area use tape. That includes the gas companies.

Honestly I do have a slight leak at the fitting on the left facing side of regulator. Was afraid to really crank the fitting so I’m more inclined to use tape and not brute force to close the leak.

Jimbo

That is what I have ordered the yellow Teflon lp tape.

Use the yellow Teflon tape on gas fittings.

In theory brass to brass does not need tape. but done properly (make absolutely sure no tape bits get into the pipe) it does not hurt.

Black iron pipe does need tape as I understand it,

If you are really worried about the posibility of a tiny leak.. Check out Locktite products.. I believe they make one just for that but key word is "Believe" I might be wrong.