On Fri, 26 Nov 2010 05:25:34 -0800 (PST), harry
wrote:

On Nov 25, 5:09*pm, Appelation Controlee wrote:
On Wed, 24 Nov 2010 11:09:53 -0800 (PST), harry
wrote:





On Nov 24, 5:53*pm, "Tim Downie" wrote:
Appelation Controlee wrote:
We had the National Grid engineer here yesterday to do a gas meter
swap-out and, in the course of this, he did a pressure test on our
installation which resulted in him giving the thumbs down to our
central heating boiler because its gas control valve seeps when
rotated (although not when it's in the service position).

So, I'm looking for a new valve.

Is it not possible to service the old valve? *I would have thought that a
bit of disassembly, cleaning and reassembly with a suitable lubricant would
fix the problem.

Alternatively, I wonder if it would be legal to fit a new isolation valve in
series with the existing one?

Tim

The above is right. *Most gas valves are not assembled dry but with a
lubricant.
It looks like vaseline (but isn't). *Your gas valve has seen little
use, it will be OK. You could illegally DIY. *Use a leak detection
spray/soapy water to check no leaks. *Clean up mating surfaces with
plastic pan scrubber.

Lube for gas valves turns out to be of a special type, presumably with
specially chained molecules, or whatever.

Anyway, the stuff I have here is a 50g tube of Rocol (R) M23660 Gas
tap lubricant. £18½ of your English pounds. (!)

Mucky stuff it is too.

Anyway, took the top off the gas valve controller and find it's a
pretty rudimentary device. I've dismantled and cleaned it, lubed the
moving bits and got as much grease as possible up the channel that the
shaft from the control knob passes through.

Re-assembled, re-fitted and there's now no "puff" of escaping gas when
the knob is depressed (which is what led the engineer to leave us in a
disconnected state).

Boiler is now running, but, lo and behold, there's a bit of a seep
from the inboard union attached to the gas meter... can't make my mind
up whether or not it's a left-hand thread. Anyone know?- Hide quoted text -

- Show quoted text -

Normal RH thread. This ia best fixed with PTFE. Use the soapy water
to detect any leaks aferwards.
You need two spanners/Stilsons whatever to undo the union to avoid
undue stress on the pipework. ie one on the union nut and one on the
union body.

Yup - all sorted now, apart from SWMBO having misgivings about safety.
:-(

I already knew about the "méthode de l'eau savonneuse" thanks. :-)