Hi,

I've done all my previous plumbing work in copper, and I'm perfectly happy
using end-feed, yorkshire and compression fittings.

But I'm a n00b with plastic pipe.
My basic understanding is this: It shoves as-is directly into push-fit
fittings, where an o-ring in the fitting provides the seal.
But you need an insert for use in compression fittings, to prevent the pipe
collapsing under the olive.
Is that basically correct?

I have some old recovered plastic pipe here, which I'd like to re-use.
It is marked "Hepworth BS7291/2 class S 15 x 2 mm H+C services and
Central Heating 12 bar/20c 7bar/82c" and has metal inserts on some of the
ends which went into copper compression fittings. These are plain inserts
with no o-rings or anything. The olives are still there, and I guess I can
probably cut the olives off and re-use the metal inserts.

Is all flexible plastic pipe basically the same, or are there different
'systems' which require matching fittings and inserts etc? Or is it just
the fittings which come in different 'systems', and each family of fittings
has it's matching inserts?

I'm a little confused about the different systems which I can find, for
example on Screwfix.
There's stuff called 'Pushfit', and 'Speedfit'. Presumably 'Speedfit' is a
brand name, and Pushfit' is just a generic term?

I see plastic pipe like this:
http://www.screwfix.com/app/sfd/cat/...15944&id=11027
It looks a lot like what I have here.
It says to use speedfit inserts.
Presumably only for compression fittings? Or perhaps for all fittings? Or
just for speedfit fittings?

The inserts are he
http://www.screwfix.com/app/sfd/cat/...26homeRef%3 D

But they have o-rings on them! What's that all about?
That suggests these inserts form a part of the sealing mechanism, and are
not just to prevent the pipe crushing in a compression fitting. So these
don't look like the right part to go into a compression fitting. I can't
imagine what they are for at all. Surely in a pushfit fitting, the o-ring
is part of the fitting, not part of the pipe insert? They don't look to be
strong enough to take the squeeze of a compression olive.

It seems to me I'd want plain metal inserts like I have to go into a
compression fitting. But I don't see those on the 'Push-fit fittings'
page at screwfix.

Looking at copper push-fit systems, I see the cuprofit ( presumably hep2o is
similar? ) require inserts in plastic pipe, even in a non-compression
fitting. These are marked 'only for use with cuprofit fittings', so I
guess they are also not the correct thing to use for a compression fitting?

So what's the compatability story here with plastic plumbing?
What inserts do you use with what pipe and what fittings?
Specifically, what inserts do I need for fitting this pipe into a
compression fitting?


--
Ron