ptfe on olives?

[Dave Plowman (News]

Not here, it doesn't. Once opened. Not in my terms as a DIY plumber.

But can't say I've ever had a problem with a compression fitting. Others, like tap connectors, yes.

[John Rumm]

Well as ever there is some variation in opinion.

Personally I never wrap olives in PTFE as a routine thing, although I have done it once or twice in extreme circumstances. I don't find it to be necessary on a regular basis. If the parts are clean and undamaged then the olive will work just fine on its own. Note however I do keep a stock of new olives - so will not try to re-use ones in a questionable condition.

Usually if a compression fitting was made successfully the first time, just separating it and re-making it is usually easy and successful. What can be more variable if reusing a back nut and olive on a pipe, with a new compression body (say when changing a radiator valve) - since the distance of the olive from the end of the pipe matters if it's too long for the depth of the pocket on the new fitting)

Using PTFE on the threads of a compression fittings, tends to raise screams of "bodge", "amateur", and "pointless" from those "in the know"

- but this seems to be because they believe that the tape was used to aid sealing. They are of course correct that since the threads of a compression fitting don't serve as a sealing surface, tape here can't help. What they are failing to understand is that tape here is not

*intended*[1] to aid sealing directly, but to act as a lubricant, making it easier (and quieter) to get adequate compression of the olive by the back nut. Once could of course use a more traditional grease or pipe fitting lubricant, although that does tend to get a bit more messy. [1] I suppose you have to allow for the part of the Venn diagram where the fitter mistakenly believed that tape on the threads would act as a sealer, in which case the cry of "amateur" etc would be justified :-)

Boss white and hemp is a traditional solution but is not acceptable for use on drinking / wholesome / potable water supplies since it can harbour microbial growth. There is a boss green that can be used, but hemp is still forbidden. (Although for a garden watering systems, the rules don't apply)

[John Rumm]

Yup IME LS-X will fix pretty much any poor joint that would be very difficult to fix properly.

[Andy Burns]

Difficult in this case was one leg of a radiator pipe that was perhaps

1/16" too short to snug-up as it used to, after laying a wooden floor on top of the floorboards, didn't want to rip up the floor in order to extend the pipe with a coupler from below floorboards level.

[Roger Hayter]

I've never come across such an interference fit, or indeed an olive that did not easily allow room for ape underneath. I don't do it now, as failed joints with standard tightening are very rare in practice if you polish the pipe and there are no visible scratches. But when I did it was always possible.

[Roger Hayter]

Or indeed 'tape'.

[Jim GM4DHJ ...]

underneath???.....you will be telling us next like brian reay did that you can remove the olive after the joint has been tightened...tee hee

[Dave Plowman (News]

You can, if the thing isn't properly tightened. Likely why so many use gunge on it. Lots seem worried about stripping the threads.

[Roger Hayter]

Actually if you put tape under and over the olive you can make a watertight joint without deforming either the pipe or the olive. But I *don't recommend* it. Because the joint can disassemble itself under slight mechanical force or even water pressure.

[John Rumm]

you can, so long as the joint has been disassembled. Going to be significantly more difficult if the joint is still done up though!

[charles]

I have a set of 15mm olive cutters to remove olives, so that I can reuse the back nut.

[Dave Plowman (News]

I'd not recommend that if it is expected to last leak free.

[Dave Plowman (News]

Just carefully cut across the olive with a hacksaw, and stop before you hit the pipe. A screwdriver in that slot then splits it. And if you buy spare olives, you can re-use the entire thing.

[charles]

It isn't always easy to get a hacksaw in the right place. other pipework often gets in the way, which is why I bough a splitter

[Fredxx]

I bought an olive extractor/puller. They can remove olives where the nut won't move back, such as on a radiator tail, and in some instances reuse the olive. The cutter is much quicker.

[John Rumm]

I find my puller works ok, but takes considerable torque to get the old one off...

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