Hello again

Wonder if I dare ask another basic question?

I have 8mm microbore feeding all my rads and I really want to change
them for some new ones (the old ones are looking rough - with the odd
rust patch appearing now). I also want to fit TRVs - and until now,
didn't realise you could get them in 8mm...! The 'Honeywell VT117E
8mm' is available from a few sites, and Plumbworld (when the website
worked a few minutes ago) did a pack with a lockshield valve.

Am I correct in thinking that a nice new rad (I'll do all the kw
calcualtions to make sure I get one that matches), a 8mm TRV and 8mm
lockshield valve, a pack of 8mm couplings (with the solder built in),
a blowtorch and some patience, I could actually pull this off and fit
a new rad?

I'm assuming these 8mm couplings (with the solder rings) are 'dead
easy' to use - so long as the pipe is clean.....(any one got any links
to some good websites that can talk me through it - I've read a few
books but am a complete amateur!).

Finally, http://www.plumbworld.co.uk/1358-12702 - is a TRV pack that
says it is for 8mm/10mm pipes - how does that work then? How can it
fit both...

Thanks in advance (and sorry for the 'newbie' questions!)

Simon

On Tue, 26 Oct 2004 21:18:40 +0100, Simon Hawthorne
wrote:

Hello again

Wonder if I dare ask another basic question?

Of course :-)


I have 8mm microbore feeding all my rads and I really want to change
them for some new ones (the old ones are looking rough - with the odd
rust patch appearing now). I also want to fit TRVs - and until now,
didn't realise you could get them in 8mm...! The 'Honeywell VT117E
8mm' is available from a few sites, and Plumbworld (when the website
worked a few minutes ago) did a pack with a lockshield valve.

Am I correct in thinking that a nice new rad (I'll do all the kw
calcualtions to make sure I get one that matches), a 8mm TRV and 8mm
lockshield valve, a pack of 8mm couplings (with the solder built in),
a blowtorch and some patience, I could actually pull this off and fit
a new rad?

You could indeed.

A few suggestions.

- Get a small, good quality miniature pipe cutter - don't use a
hacksaw. Plumber's merchants sell them quite inexpensively, normally
made by Rothenberger. Make sure you get one that will cut down to
8mm, some of the large ones won't or mangle the tube.

- Get a small hand held pipebender for microbore tubes. You can get
a cheap one for about about £15 e.g. Screwfix 17898

You may need some 8mm copper tube as well. It's better to get some
that is fairly new because it is then softer to work with - it hardens
as it ages.

Don't forget to get a heat mat to put behind the work when you are
using the torch.


I'm assuming these 8mm couplings (with the solder rings) are 'dead
easy' to use - so long as the pipe is clean.....(any one got any links
to some good websites that can talk me through it - I've read a few
books but am a complete amateur!).

They are. Essentially it's a case of thorough cleaning, smear on some
flux and heat with blow torch, applying solder when the piece is hot
enough. One thing with small tubes like this is not to overdo the
solder. It can run inside the fitting and partially or completely
block the pipe. You only need a small touch - none if you use solder
ring fittings.



Finally, http://www.plumbworld.co.uk/1358-12702 - is a TRV pack that
says it is for 8mm/10mm pipes - how does that work then? How can it
fit both...

It probably comes with alternate compression olives or a reducing
ring.

How long are the pipe runs going to be? For up to a few metres (say
less than 10 total flow and return then you can run a radiator of up
to about 1500W rule of thumb. If it's longer then you will need
larger pipe - e.g. 10mm will do 2500W.




..andy

To email, substitute .nospam with .gl

On Tue, 26 Oct 2004 21:18:40 +0100, Simon Hawthorne
wrote:

Hello again

Wonder if I dare ask another basic question?

I have 8mm microbore feeding all my rads and I really want to change
them for some new ones (the old ones are looking rough - with the odd
rust patch appearing now). I also want to fit TRVs - and until now,
didn't realise you could get them in 8mm...! The 'Honeywell VT117E
8mm' is available from a few sites, and Plumbworld (when the website
worked a few minutes ago) did a pack with a lockshield valve.

Am I correct in thinking that a nice new rad (I'll do all the kw
calcualtions to make sure I get one that matches), a 8mm TRV and 8mm
lockshield valve, a pack of 8mm couplings (with the solder built in),
a blowtorch and some patience, I could actually pull this off and fit
a new rad?

I'm assuming these 8mm couplings (with the solder rings) are 'dead
easy' to use - so long as the pipe is clean.....(any one got any links
to some good websites that can talk me through it - I've read a few
books but am a complete amateur!).

Finally, http://www.plumbworld.co.uk/1358-12702 - is a TRV pack that
says it is for 8mm/10mm pipes - how does that work then? How can it
fit both...

Thanks in advance (and sorry for the 'newbie' questions!)

Simon

Do you need to solder ?

Just compression join the new vaules on the pipes in the same place as
the old ones.

If you have never soldered, then you can (shh say the quietly)
compression join, (real hush down now) or pushfit ?

If you goto a good plumbers merchant, in person, on a quiet day, and
buy the stuff, they will probably give you a soldering lesson ........

Rick

Do you need to solder ?

Just compression join the new vaules on the pipes in the same place as
the old ones.

If you have never soldered, then you can (shh say the quietly)
compression join, (real hush down now) or pushfit ?

If you goto a good plumbers merchant, in person, on a quiet day, and
buy the stuff, they will probably give you a soldering lesson ........

Rick


if you have never done it before then practice on a couple of fittings and
some offcuts of pipe first. I did it for the first time quite recently and
it was very easy, especially with solder ring fittings. If you have ever
soldered anything before (even electronics) you will have an advantage of
knowing what flowing solder should look like. As already mentioned you need
to get the joint as clean as possible - that is both the pipe end and the
inside of the fitting, I used green scotchbrite but some people use wire
wool.

Thanks again all. I'm off to buy a bag of bits, and as suggested,
have a go on some bits of pipe away from the 'work'. Might end up
with a really nice sculpture that I could sell the local council for
£10,000 - so they could erect it on a roundabout near here!!

Seriosuly though, thanks. This newsgroup really is the best.

Kind regards

Simon

Simon Hawthorne wrote in message . ..
Thanks again all. I'm off to buy a bag of bits, and as suggested,
have a go on some bits of pipe away from the 'work'.

Emm, just to counteract the more positive replies already received here,
in my experience I have had "problems" with 8mm microbore and TRVs.

I still use 8mm in the house (I used it in a self-designed "underfloor
take the chill of the floor tiles" project, with much success).

With the 8mm TRV I found that it was a reasonably standard TRV with a fancy
olive to reduce from 15mm to 8mm.

The olive was "special" such that when you fitted the TRV the wrong way round
(yes, I appreciate my mistake) then removing it proved problematic.
No need to lecture me on the amount of compression required please - I made
the mistake and I paid for it.

So the eventual conclusion (apart from some consideration of my own
competence) was to use 8mm piping where it was warranted but fit 8mm-to-15mm
converters and just buy standard 15mm fittings for the connection to the
radiator.
When someone accidentally whacks a vacuum cleaner against an 8mm pipe it may
suffer more damage than if it were to be a 15mm pipe.

Your Mileage May Vary.



Seriosuly though, thanks. This newsgroup really is the best.


Seriosuly (!) I thoroughly agree with you. Just remember that when you
gain some expertise in an area then please consider sharing your knowledge
with all the other readers of this newsgroup.
Mungo :-)

On 27 Oct 2004 06:27:46 -0700, (Mungo Henning)
wrote:

Simon Hawthorne wrote in message . ..
Thanks again all. I'm off to buy a bag of bits, and as suggested,
have a go on some bits of pipe away from the 'work'.

Emm, just to counteract the more positive replies already received here,
in my experience I have had "problems" with 8mm microbore and TRVs.

I still use 8mm in the house (I used it in a self-designed "underfloor
take the chill of the floor tiles" project, with much success).

With the 8mm TRV I found that it was a reasonably standard TRV with a fancy
olive to reduce from 15mm to 8mm.

The olive was "special" such that when you fitted the TRV the wrong way round
(yes, I appreciate my mistake) then removing it proved problematic.
No need to lecture me on the amount of compression required please - I made
the mistake and I paid for it.

So the eventual conclusion (apart from some consideration of my own
competence) was to use 8mm piping where it was warranted but fit 8mm-to-15mm
converters and just buy standard 15mm fittings for the connection to the
radiator.
When someone accidentally whacks a vacuum cleaner against an 8mm pipe it may
suffer more damage than if it were to be a 15mm pipe.

Your Mileage May Vary.


These are good points.

In some cases I've used 15mm x 8mm reducers - i.e. 8mm female socket
with solder ring (or not) and 15mm male tail. The tail goes into a
standard 15mm TRV.

e.g. BES part number 9213.

The reducing sets that I think you are talking about are indeed
questionnable IMHO.
Firstly it is non-obvious how to fit them together, and secondly they
seem to have a propensity to leak, even if you do use a tube cutter
and not a hack saw.







Seriosuly though, thanks. This newsgroup really is the best.


Seriosuly (!) I thoroughly agree with you. Just remember that when you
gain some expertise in an area then please consider sharing your knowledge
with all the other readers of this newsgroup.
Mungo :-)

..andy

To email, substitute .nospam with .gl

On Tue, 26 Oct 2004 21:18:40 +0100, Simon Hawthorne
wrote:

I'm assuming these 8mm couplings (with the solder rings) are 'dead
easy' to use - so long as the pipe is clean.....(any one got any links
to some good websites that can talk me through it - I've read a few
books but am a complete amateur!).

These sites are aimed at soldering small electronic parts but the
principles are similar.

http://www.mtechnologies.com/building/atoz.htm
(click on Soldering 101)

http://www.epemag.wimborne.co.uk/solderpix.htm

Others have given most of the advice you'll need; there's just a couple
of other things I can think of:

The test of a good joint is a narrow continuous ring of shiny solder all
around the pipe at the pipe/coupling junction. Any gaps in the ring are
usually due to inadequate cleaning. It is said that a modern 'active'
flux copes well with uncleaned pipe, though I always polish up the pipe
and coupling inside with fine wire wool.

You could use 15mm valves with 15/10 or 15/8 reducers to adapt to your
pipe if that gives a cheaper overall solution.

Phil
The uk.d-i-y FAQ is at http://www.diyfaq.org.uk/
Remove NOSPAM from address to email me

On Wed, 27 Oct 2004 06:27:46 -0700, Mungo Henning wrote:

Simon Hawthorne wrote in message . ..
Thanks again all. I'm off to buy a bag of bits, and as suggested,
have a go on some bits of pipe away from the 'work'.

Emm, just to counteract the more positive replies already received here,
in my experience I have had "problems" with 8mm microbore and TRVs.

I still use 8mm in the house (I used it in a self-designed "underfloor
take the chill of the floor tiles" project, with much success).

That's interesting - I'm considering underfloor heating.

I note that there are various kits available using plastic pipe to bury in
the screed. But what about copper? I would think it's more durable.

Could you enlighten me on how you did it, Simon? Did you bury 8mm in the
screed and leave the tails above ground - or did you wrap the pipe with
anything first?

Ta

Timbo