"Hepworth Plumbing Products Team" wrote in
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"John Stumbles" ] wrote in message
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"IMM" wrote in message
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"BillR" wrote in message
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Zetor wrote:
Hi,
I just had a new combi boiler fitted by 2 extremley efficient
gas
fitters, they did a really good tidy job, on talking to them about
the
use of plastic pipes I ask why they still use copper, they said
that
they still use copper for the central heating pipes as it is far
better then plastic as they didn't believe plastic was as air
tight as
a good soldered joint. They had even replaced boilers of only 2
years
old which had corroded due to poor installtion and extensive use
of
plastic pipes. Does anyone know what conditions air could get into
a
sealed system like me combi? I have one radiator which is plumbed
in
plastic and now wonder if I should maybe get it piped in copper.

Zetor

British Gas won't allow maintainance contract on system with plastic
pipe
that doesn't have a barrier layer.
That doesn't mean to say that such systems are no good, its just
that
they
are very fussy (and seriously overcharge). You can see the barrier
layer
if
you look at the pipe end, its a ring in the middle of the wall.
All the hepworth stuff in my local Jewson's seems to have it.
Allegedly without it minute amounts of oxygen can permeate through
the
plastic.
You can plumb a system with far less joints in plastic, so its
quicker
and
overall less risk of leaks.
You cannot use it for gas or within 1/2M or so of the boiler CH
flow/return.

Marley Equator and Speedfit pipe is barrier pipe. The other makers
have
two
types. Non-barrier and barrier. You need the barrier pipe for CH.
the
none barrier is fine for hot and cold water systems.

Well those stetson-wearing folks at the Hepworth ranch say:


http://groups.google.com/groups?selm...40news11-gui.s
erver.ntli.net

In particular:


"""""""""""""""""""""""""""""""""""""""""""""""""" """"""""""""""""""""""""""
"
If Hep2O Standard pipe has been installed in accordance with our
instructions in a central heating system and one of the recommended
inhibitors used there is no technical reason why it should not continue
to
give good service for many decades.

Some of the British Gas regions only accept Hep2O Barrier Pipe on their
service contracts. This is their commercial decision. Of course British
Gas
no longer hold a monopoly on maintenance schemes for heating systems and
there are other insurance backed schemes available from various
organisations, which will accept both Standard and Barrier pipe.


"""""""""""""""""""""""""""""""""""""""""""""""""" """"""""""""""""""""""""""
"

It is all silly. All
pipe should be barrier pipe then there will be no problems.


Having worked with both barrier and non-barrier pipe and compared the
ease
of getting it where I want it -- especially 22mm (or even 28mm) -- I now
buy
non-barrier pipe (even though it costs more).


If you can fit copper then do so, and only fit plastic where it is
required.
If speed and ease of installtion is the point then use copper with
brass
push-fit fittings, which now are about the price of plastic fittings.


They all use 'rubber' (EPDM or some such) 'O'-rings to make the seals,
whether they're brass, copper, stainless-steel or plastic on the
outside.

As an update to the information posted previously, British Gas have
revised their internal policy and now accept Non-Barrier (Standard)
pipe as well as Barrier pipe for their service contracts. This change
took place earlier this year.

It is now considered by British Gas that central heating systems that
include plastics pipe manufactured to the appropriate British Standard
(such as Hep2O) do not represent a potential corrosion problem from
oxygen ingress where the system water includes an adequate strength of
inhibitor. This applies equally to Barrier and Non-Barrier pipes.

At the same time as this change took place, a test for inhibitor
strength and a turbidity test to check for debris/corrosion deposits
were introduced by British Gas for all systems, including those piped
in copper.

Hepworth have always advised that all central heating systems should
have inhibitors installed.

If fitting UFH and use plastic pipes without a oxygen barrier use
non-ferrous throughout the system, Such as:

- None-ferrous heat exchanger in the boiler
- Plastic pipe with ferrous pipe inserts.
- A brass or bronze pump




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