On Sun, 08 Jan 2006 20:26:26 +0000, in uk.d-i-y Mike Myers
wrote:

On Sun, 08 Jan 2006 15:35:12 GMT, Phil Addison
wrote:


Why would you want to cut it, unless it is damaged? It must me in good
condition, and you must use the special stainless steel inserts in the
cut end to support the pipe wall at the fitting end. Actually I'm not
sure if that is true for 10mm, but it certainly is for 15mm - check on
the Hep20 website http://www.hepworthplumbing.co.uk/

Sorry for the confusion, what I mean is I am taking off existing
radiator valves which are terminated into HEP20 and replacing them for
new valves, 2 of which will be TRVs. (the old valves are weeping and
look cruddy).

If I remove the existing pipe, will it be ok to terminate to the new
valves, or will I have to cut the existing end which has the
compression olive and fit new?

I am assuming the pipe will already have the stainless steel inserts,
and the old olive (wont that be damaged due to the compression fit?).

They are usually ok to re-use so long as it hasn't been over-tightened.
Check it has not cut too deeply into the pipe if re-using it.

I had assumed I fit new inserts and new olive from the new valve then
remake the compression joint. I has assumed this is why I would have
to cut the end of the pipe.

You don't get inserts with valves. They come from the plastic pipe
supplier.

The compression nut will normally be trapped on the pipe by the olive.
You then have two options. Use the existing trapped compression nut to
attach the pipe to the new valve (clean up the threads first if caked
up), or cut the pipe back to a clean portion and use a new insert
(ideally, but you can get away with re-using the same one) and your new
fittings. You may need to extend the pipe with copper as I mentioned
before. Use a very light smear of Boss White on the olive (not the
threads) and before reassembling. The Boss White is for lubricating the
joint during tightening as much as it is for sealing. Don't use Boss
White on any plastic fittings, should you have any.

Thanks and sorry for my silly questions but I am a novice with this,
and my dad who has done his own copper work doesn't know about
plastic.

Not a silly question at all - we all started at the beginning. I bet it
won't be long before you are answering questions here.

Phil
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