"Set Square" wrote in message
...
In an earlier contribution to this discussion,
Frank Stacey wrote:

For various reasons I find that a plumbing job on which I have
embarked involves using plastic (HEP) pipe for various awkward runs
with copper at either end. Am I right to assume this can be done
without restriction?

In some places I am using straight metal compression couplers between
copper and plastic with an insert in the plastic pipe. In other
places I have plastic elbows with plastic on one branch and copper or
chrome plated copper on the other. Are there any gotchas I should
know about?

Excuse the paranoia, but once completed most of this stuff is going
to be under the floor of a small bathroom and very inaccessible. I
dread having to rip out my carefully installed fittings as water
seeps through the ceiling below!!

Frank [the tentative plumber]

That'll work fine. Just make sure that all pipes - whether copper or
plastic
are pushed home fully into the fittings. (make a mark on the pipe with a
felt-tip pen the right distance from the end, and make sure that this is
only just visible).

My only reservation would be chrome plated pipe - having never used any!
It
may be ok, but I would be slightly worried in case the chrome is too hard
for the star-lock washers to dig into and grip properly. I would be
tempted
to use compression joints here.

When faced with a similar _problem_ ^W opportunity ... I did attempt
plastic to chrome joint: it failed under pressure with the plastic fitting
easing off the slippery chrome. I de-chromed the end by using one of
those pipe-end cleaners - it's a plastic tube -gauged for 15mm one end and
22mm at t'other- each end has flap-style abrasive thingies; push the
pipe into appropriate end and twist aggressively- result shiny copper
for the correct depth for jointing. Second time around with what was
now Copper~Plastic; no problems.

--

Brian