On Tue, 18 Dec 2012 08:56:45 +0000 (GMT), "Dave Liquorice"
wrote:
On Mon, 17 Dec 2012 20:11:33 +0000, T i m wrote:
As an aside, I've been able to turn the isolation valves (good old
Leatherman PST II) and I've located a drain cock if it comes to it.
If the isolators do turn, ...
Make your mind up...
Yeah, sorry, I should have said 'as'. ;-)
... might they not still isolate and if so is it general practice to
change them at the same time?
Are they gate valves or ball valves?
Ball.
I'd almost put money on gate valves
either not turning and/or not shutting off enough.
Understood.
I also expect that the orginal insaller used fibre washers between the
pump body an valves as well.
Ok.
Can you see signs of that (rust on the body under the top nut) in this
pic?
https://dl.dropbox.com/u/5772409/Myson%20Unit%203a.png
These will probably have leaked just enough
to cause the pump body to corrode and weld everything together. I've had
to cut pipes above and below and remove the whole lump before now and
even with the lump held in a vice and good grip not being able to shift
the flange nuts at all.
;-(
I have blowlamp, hammer a cold chisel, Bosch 'Multitool', some 'f-off'
pump pliers, big 'F' adjustable's and possibly even a big std
adjustable that will go up to 52mm at the ready. ;-)
When refitting use ball valves (assuming that the ones there don't work),
synthetic washers and a smear of silicone grease on the mating faces and
thread.
Ok (The silicone grease was mentioned elsewhere).
http://www.screwfix.com/p/pegler-pump-valve-22mm/20850
If we do replace the valves, are these worth the extra would you say
please (I'll check her pipework is actually 22m etc).
This will ensure that you never have to replace the pump again.
LOL. Sounds about right!
Use gate valves and fibre washers and it'll fail within 2 years and the
gate valves will have siezed/not seal, again...
Understood. So I believe the pumps 'normally' come with washers. So
say I bought a Grundfos from SF this morning, would it likely come
with synth washers or would I have to buy those separately (from)?
http://www.screwfix.com/p/grundfos-u...ing-pump/50183
Cheers, T i m