Why ptfe tape on compression fitting threads

[Koogatubac]

As a apprentice for some strange reason i used PTFE on olives and i used to get the odd weap

When i turned a engineer, i started using jet blue and very very rarely get leaks!
Would be lost without jet blue! Best stuff ever!

 

[RPG 80]

As a apprentice for some strange reason i used PTFE on olives and i used to get the odd weap

When i turned a engineer, i started using jet blue and very very rarely get leaks!
Would be lost without jet blue! Best stuff ever!

perhaps you've got stronger wrists now


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[Phil]

I'll have to get some of this jetblue.

JetBlue | Airline Tickets, Flights, and Airfare

 

[Mike Jackson]

As far as I'm concerned the only time you need any extra sealant is if you are going onto old pipe or re using an old fitting. The last 4 jobs I've done have had no extra sealant used except for the rad valves that I've changed on the old pipework. 2 of these were unvented with no sealant used on any of the compression fittings and no tape used on threaded fittings, just a smear of loctite 577.

 

[ally]

tape on rad valves don't need any on olives unless using old fittings, works for me

 

[adam84]

Anybody had trouble with Danfoss TRV's lately?

Very shallow fitting depth and a very hard brass olive has resulted in the dreaded wet finger the day after around the pipe.

I always have to PTFE these olives now as three in a row leaking is a right pain.

The danfoss are my TRV of choice but agree competely with what your saying, i change the olives but the thread on the valve is so shallow i spend ages trying to dig out a deeper olive. :nonod:

 

[Mickyplumb]

Why ever take the chance of a leak ? How long does it take to run a couple of rounds over an olive.

 

[Best]

Conex olives are a bit deeper, so are good if you wanted to change the Danfoss olives. The olives supplied with Danfoss valves do need you to use a bit of force, but are okay if you use paste & anyhow, paste helps you tighten as it lubricates. Ptfe tape is not as good as paste for sealing olives.
My argument with anyone saying they don't use paste & have no leaks, is - what are all the joints without paste like in a few months & then a few years? Microscopic leaks I think, especially with poor quality fittings or olives.
Never use those olives that are flat, except having a very small tapered edge. Bin them, but if you do use them, use paste, or they leak a bit.

 

[tamz]

Never had a problem with any compressions other than the cheap Italian shyte.
If it is not leaking when you leave it, it won't be leaking next year.

 

[Best]

Never had a problem with any compressions other than the cheap Italian shyte.
If it is not leaking when you leave it, it won't be leaking next year.

What I meant was, you can run your finger around a joint, or a piece of tissue, & it will be dry, but the joint could be leaking very very slightly. So slightly it virtually evaporates I guess. Then you get the white corrosion on lots of the nuts & rest of fittings in a few months/years. Looks terrible & the nuts are seized when you need to do a simple job.
Must admit, cheap Italian brass fittings are the worst for this, but will happen to some degree with others.