Compression fittings on plastic pipes?

I've just been contemplating a tap-replacement project, and considered (ok, I've just bought) flexible tap pipes - the type with braided hose and a compression fitting at one end. The obvious problem is how to use the compression fitting on the existing plastic piping?, a quick google suggests that you need an insert for the pipe (I can imagine a copper sleeve with a slight rim, that is inserted into the end of the cut plastic pipe - to avoid undue distortion to the plastic pipe when the olive bites).

Is this the right track (in which case, I really, really should have included these in the old screwfix order) - can these be *readily* picked up (i.e. in the Sunday sheds, rather than plumbers merchants (who all seem to close at the convenient times for most people in full-time employment)

Regards

Mike

Reply to
Mike Dodd
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In article , Mike Dodd writes

Yes that's right, metal insert on Hep (I think) and plastic on speedfit, available from all good Plumbers' merchants :-) and probably those stinking sheds too (at inflated prices, look for the trade pack).

The joint is v positive on pinch-up, just don't over tighten. For a few pence more, Speedfit inserts are available with an extra O-ring on the body for a more positive seal but I don't think that you gain anything on the compression joint as the seal is on the pipe. I do all transitions between copper & plastic in compression as I like the joint to be at least as strong as the strongest material to be joined (IYSWIM).

Reply to
fred

I did exactly the same job t'other weekend, following the recommendations of the John Guest website

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You definitely need to use an insert on the plastic pipe (preferably from the same brand name as the pipe). I wrapped some PTFE tape around the outside of the olive as an alternative to a proper sealant but not sure if it made any difference to the result.

You don't need to tighten the fitting much, it should make a good seal quite easily.

Reply to
Vaci

In article , Vaci writes

If you need either then you're doing something wrong, also the ptfe will be cut through on the first turn of the nut so won't really be doing anything.

Reply to
fred

The sheds sell the Hep2O inserts in packs of 10/20 at quite a price. Your local plumbers merchant will sell you just one or two for 27p each (22mm) which is what I last paid. Search

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for item number 15143 for

15mm pipe support.

I connected the plastic 22mm bath feeds to the flexible tap pipes in my last house, using sleeves in the plastic pipe to compression full bore valves (so I could turn the water off) then via a tiny bit of 22mm copper to the compression fittings on the flexible pipes. You use 22mm copper from valve to flexible pipe its cheaper than doing it in plastic (ie save 4 inserts). Also cut the pipe using a sharp knife not hack saw as it must be a clean end and side walls in order to seal properly.

You also buy a spare insert, which you label as spare, as I assembled everything, then found the spare and thought "sh*t missed an instert off", took it all apart, "bum, no missing insert, oh I remember I had a spare, sh*t sh*t sh*t" and promptly dropped an insert down under the bath and down the waste pipe boxing to downstairs.. Luckily I had a spare !!!

Reply to
Ian_m

Actually, it was the Hepworth instructions that recommended using PTFE:

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guess it just avoids rotating the olive around the pipe when the nut is turned?

Reply to
Vaci

"Use PTFE tape over olive if lubrication required." Yes, I see the point, lube rather than sealing, thanks for the clarification.

Reply to
fred

If you didn't have the spare in the first place you wouldn't have needed it ;-)

MBQ

Reply to
manatbandq

Hi, There is some useful info on this website that might help you little 'joining pipes

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Of th few DIY websites based in the UK, this seems to offer more informatio with less damn adverts

-- weekendwarrior

Reply to
weekendwarrior

Many thanks to all those that answered.

Unusually, all helpful and kept to the topic :)

Thanks

Mike

Reply to
Mike Dodd

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