PTFE or Loctite577 on thread

[Bogart]

Most of my lockshield valves are the compression type onto the radiator tail. Have just installed a couple of the union type face to the tail lockshields. Smeared a bit of boss white on the face but am wondering if I should have used ptfe tape, or my preference loctite 577 on the actual union threads. No water in them yet so can do if you deem required.

 

[ShaunCorbs]

Did they tighten up / tapered threads if not ptfe / loctite 55

 

[Bogart]

Seemed to tighten okay but am wary. Just so that we are talking of the same part, I easily mislead you guys , attached is a pic.
The arrow is pointing to the area where inside there are 2 brass faces just pulled together by the screw action. As I say I have put a bit of boss white on the faces. Just wondering if that is enough as there is not the satisfying feel of an olive tightening up.

 

[ShaunCorbs]

That’s fine with boss white / joint compound I do the same

 

[Bogart]

Many thanks. I really appreciate all the help I get here. A Merry Christmas to you all.