Irish plumbing

[Guy King]

may have seen this before - and of course it's not restricted to the Irish, I've seen stuff like this in the UK often enough.

[Andy Dingley]

I've dealt with Irish (Northern) plumbers and have _never_ met such a cack-handed bunch of bodge merchants in my life. Except perhaps my sister-in-law's plasterers, who managed to burn the cavity wall insulation out - by lighting a fire to keep warm, before the fireplace hearth was installed or the flue properly lined. We got off lightly, with merely the toilet cistern overflow that disappeared into an internal wall, the bath that had to be bailed through the window to empty it (and was self-filling in heavy rain) and of course the infamous Night of the Zombie Septic Tank.

IMHE, it's down to the blatant nepotism that's rife in NI. "Ach, wee Jimmy will see you right" usually means "My idiot nephew Jimmy needs the work, as he's an inbred halfwit with vestigial gills. However we all drink at the same rugby club, and it's not either of us who has to live there afterwards".

Oh, and they're not a patch on landfill contractors who turned our garden into an asbestos waste tip. Still, there was a drink in it for the right people, so that's alright then.

[John Stumbles]

The "Cistern overflow pipe and vent over flue" also shows the flue being unacceptably close to an air vent.

Overall interesting, but sad that the text is as shoddy in places as the work it illustrates.

[Chris Cowley]

The page

states:-

"PTFE joint tape in the thread of compression fittings is a common sign of uninformed DIY."

Where exactly is one supposed to put PTFE tape if not on the thread of compression fittings?

[Christian McArdle]

Well, certainly not on the thread of compression fittings. A compression joint works with a seal between the fitting and olive and between the olive and the pipe. These are metal to metal joints. Some people wrap the olive in PTFE, but this is unnecessary and could even cause leakages in the future if the PTFE degrades and there is no actual metal to metal seal.

The thread on a compression joint is not part of the water seal and should not have PTFE applied. The sign of a professionally done compression joint is the use of no PTFE at all.

PTFE is used on BSP fittings usually with a jointing compound. Examples are radiator tails and outside taps, where the thread IS part of the water seal.

Christian.

[Guy King]

The message from Chris Cowley contains these words:

Well, I've never used it on compresion fittings - I've always used it on taper-threaded iron fittings.

[John Rumm]

Its real purpose is when you have to make a joint that requires a seal to be made on the threaded part of a connection.

A compression fitting makes a seal between the pipe and casing by use of the olive - the threaded part itself does not even come into contact with the water.

(In spite of it not being required, I personally still like a couple of turns on the thread of compression fittings since it lubricates the joint a little making it easier to do up tight, and disassemble later if required).

[Christian McArdle]

Personally, I prefer to avoid it. If there is something sealing the thread, it may obscure the fact that the olive seal has failed.

Christian.

[Doctor Drivel]

That is the place, on taper threads. A light smear of paste is all that is required on a compression joint. The only place to wrap PTFE around an olive is when using compression on plastic pipe, as that is what the makers say.

[Doctor Drivel]

I have nothing like that all in one place. How about in Poland?

[Guy King]

The message from "Doctor Drivel" contains these words:

I don't even do that - just a smear of copper grease to stop it getting stuck later.

[John Stumbles]

You mean without, Shirley?

PTFE tape OR jointing compound (e.g. Boss White) poss. with hemp.

[Christian McArdle]

Nah, with. I smother the PTFE in Fernox LS-X. Works every time. Never once a leak, even on parallel BSP.

I see PTFE as the hemp replacement and LS-X as the Boss White replacement.

Christian.

[Chris Bacon]

Things such as radiator tails. Taper threads. Gland packing, possibly. Not in compression fittings.

[Christian McArdle]

Not me. I only ever use the pipe and the compression joint. Nothing else at all. No tape, no gunk.

Christian.

[Christian McArdle]

P.S. No news yet.

Christian.

[Chris Cowley]

[snip]

Oh right. I never knew - I've always used PTFE on compression threads as lots of sources seem to say it should be used (e.g. various DIY books,

guess I can save myself a few pennies by stopping using it, then!

Cheers,

[Sponix]

1. It ensures the thread doesn't seize and the joint can be tightened/dismantled easily at a later date.
2. It seals the thread. This can prevent a leak should any water find it's way between the outside of the olive and the main body of the joint. I agree that in theory a compression joint should be perfectly machined but in a lot of cases they aren't.

sponix

[Sponix]

..in Theory. Of the olive seat/olive is less than perfect then water can seep past.

sponix

[Christian McArdle]

I'd rather know about it and discard the fitting (I've not come across one yet).

If you seal the threads, then you won't know you've got a dud. At least not until a few weeks/years later.

Christian.