The Medway Handyman wrote:
John Rumm wrote:
The Medway Handyman wrote:

Do you have to solder? For grafting bits onto an existing system, I
find that a service valve (full bore) and a pushfit fitting of some
sort (cuprofit look almost as neat as capillary) will let you cut
into a "live" system and not lose more than a cup full of water. You
can then extend at your leisure and use the valves to finally bring
the new bit online.
By 'live' do you mean full of water under header tank pressure?
Yup, or on a sealed system - just drain a little water from it to drop
the pressure before you start. (a couple of litres will normally be
enough).

My preferred technique is have the fitting and valve ready assembled,
and use a pipe cutter on the offending pipe (close to somewhere like a
rad valve so that there will only be water flow from one direction).
Once it starts to hiss, cut a bit further, and then give a sharp
wiggle to snap off the pipe, placing your thumb over the wet end as
you do. Now pick up the prepared fitting, and swap its position for
your thumb. Finally wipe your glasses to remove the splashes! ;-)

(Old towel under the work area of course!)


Who dares wins huh?

Sure - show it who is boss!

I'll bear that in mind...

Just don't do what a mate of mine did... needed to get a compression
service valve onto a rad feed and return pipes such that they could be
split to add a new rad. I had described the technique well enough I
thought - I was upstairs when I heard the yell. Came down to find one
rather wet looking chap standing next to a rad tail with service valve
attached, and a floor and ceiling covered with black gloop! He said,
"you can do the other side!". So, cut, wiggle, thumb, pre-assembled
valve on and held down to obstruct 85% of the flow, quick turn with a
spanner to halt the rest, before finally tightening into final position.
While watching he then said, "oh, I see - you put the whole valve on
in one go..."

Turns out that having cut the pipe, he then set about sliding over first
the backnut, then olive, then valve body, all the time doing the thumb
hokey-kokey before finally attempting to get them all together and doing
up the nut.

--
Cheers,

John.

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