Tape, paste or nothing?

[Topcat33]

Could you tell me if these fittings in the photo require ptfe tape or paste on any part of the thread as they have a rubber washer within the thread so I assume not. Thank you

 

[Stuckinarut]

Do they come with instructions? If yes follow these, but I’d say they don’t require anything.

 

[Madrab]

Looks like the threads already have paste/tape applied to them.

 

[Topcat33]

Looks like the threads already have paste/tape applied to them.

I know my photos are bad but you may need to have a closer look

 

[Rodders53]

via Google lens I found one manifold pressure gauge that has a "Teflon ring" and looks a bit like the black thing above (on the RS components site); although the hex part is brass on the RS item. Most such gauges are all brass thread needing some suitable sealant.

What are the two things, and what are they to be fitted to?

More info would help identify and allow those who know to say with more certainty for the intended application.

 

[Madrab]

I know my photos are bad but you may need to have a closer look

Why ... magnified it still looks like ring of PTFE (Teflon), come across plenty of items before now that need tape or paste to provide the seal, where it's already been applied to the threads.

If it's not that then it may be easier to explain what it is rather than having to guess what it is from a pic.

 

[Topcat33]

Why ... magnified it still looks like ring of PTFE (Teflon), come across plenty of items before now that need tape or paste to provide the seal, where it's already been applied to the threads.

If it's not that then it may be easier to explain what it is rather than having to guess what it is from a pic.

Ah, my apologies I see what you mean now, that that is literally a ring of ptfe. I thought there was a gap in the thread but maybe not.
The top one is a pressure gauge and the bottom one is a fill adapter, both off a new boiler.

 

[Madrab]

that that is literally a ring of ptfe

Yes indeedy - the trick with PTFE is knowing how much to use to ensure the threads seal properly and some of the better manufacturers take the guess work out of it and apply the correct amount of sealant themselves. Then it's just a case of screwing it in and it should seal up properly.