"Arfa Daily" wrote in message
...
Bit of a long post, but stick with it ... :-)

So, today, I finally got the time to go to our burger joint to fit the
pressure reduction valve that I bought a couple of weeks back, to stop the
6 bar pressure relief valve ahead of the unvented water heater, from
lifting off its seat all the time. For those who haven't seen the valve in
my earlier posts, here it is :

http://www.plumbworld.co.uk/safeguar...cing-343-21866

It has a 22 mm through bore, and comes complete with custom 22 to 15 mm
reducing olives, as well as standard 22 mm olives, if you are going to fit
it direct to 22 mm pipe. So far, so good. Off goes the water, on go the
taps. All drained down, and three inches whipped out of the 15 mm pipe
where it's going, in no time. I then fitted the compression nuts over the
pipes, and then put the two sections of the reducing olives over the pipe
ends, after carefully studying the supplied diagram to make sure that they
were going in right. The diagram is quite clear, and the assembly order is
exactly as you would expect. Basically, the 'inner' part of the olive
comprises a 'straight' section about 5 mm long that fits into the body of
the valve. Behind this, there is a 'flare' at about 45 deg that matches a
correspondingly angled 'seat' in the valve body. Behind that is a
'conical' section of again about 45 deg, tapering down the opposite way to
a 15 mm hole to accommodate the 15 mm pipe. This is the piece of the
adaptor, that is going to grip down onto the 15 mm pipe. There is then a
completely separate piece that is a brass ring about 5 mm deep, that has a
corresponding conical seat inside its front face, and a square rear face
to go against the inside face of the compression nut. Unfortunately, the
online instruction sheet doesn't show this, so I've had to try and
describe it.

What should happen, is that as you pull up the compression nut, the
conical seat of the outer ring, presses on the conical taper of the inner
part of the adaptor, crushing it onto the 15 mm pipe. At the same time,
the 45 deg flare a little further in, should be pulling up against the
corresponding seat in the valve body, to form a seal.

Except it didn't. Both sides dripped like a good 'un. The low pressure
side was actually worse than the high. And from here on in, the day just
got worse. I had been careful not to pull the nuts up more than about a
quarter turn beyond where the adaptor had obviously gripped the pipe, as I
am fully aware that over-tightening a compression fitting can distort it
and prevent it sealing. So I carefully pulled it up a bit tighter. Not a
jot of difference. Water off again. Disassembled. Inner part of adaptor
seemed to be tightly pinched onto the pipe. I carefully examined the flare
and the seat in the valve, but both looked ok and undamaged. However, as
that was about the only place that I could see that water could be getting
past, I put a good wodge of PTFE tape around the flare, and bolted back
up. And still it leaked ...

Thinking that perhaps I was wrong then about where the water was getting
out, I then nipped to B&Q and bought a couple of end-feed 22 to 15 mm
reducers, that had nice long straight bits at the 22 mm end. As a safety
net, I also bought a pair of 15 mm straight couplers. Glad I did ...

With the valve back off, I fitted the supplied 22 mm traditional olives
over the reducers, and inserted them into the valve body. Nice fit, and
the olive is butting up to the seat in the valve nicely. Out with the
cutter again, and a bit more pipe removed to accommodate the new length of
the valve with it's reducer 'tails' fitted, and to allow the original
reducing olives to be removed, as of course, these are now firmly clamped
to the pipe, never to come off ...

Valve back in place, compression nuts pinched up, olives appear to be
clamped firmly to the 22 mm sides of the new reducers. Other ends of the
reducers soldered to incoming and outgoing 15 mm pipes. Water back on.

AND THE ******* LEAKED. BOTH EFFIN' SIDES !!!!!

No amount of additional tightening, PTFE'ing, swearing at it or kicking of
the cat that wandered past the back door, would improve it. So, with time
marching on towards opening, I gave up, and fitted a piece of 15 mm pipe
back into the gap, using those two couplers that I had fortuitously
purchased ...

As both (very different) ways that I've tried to mount this thing have
failed to work in the same way, and the fact that the low pressure side is
actually worse than the high, the only conclusion that I can come to, is
that the example that I have has been machined badly at the olive seats,
or else the product overall, is a piece of ****. During over 40 years of
DIY plumbing, I think I've seen most general problems of this type, and I
don't ever remember one defeating me before. I'm not an expert by any
means, but compression joints and adaptors, are hardly rocket science. I'm
not sure what to do now. I was thinking that I might be able to get an O
ring in between the olive and the seat, but I'm not sure that would be
successful. Anyone got any suggestions, or can think of anything that I'm
doing wrong, or missing. Incidentally, when it was in place, with the
pressure gauge fitted, it did at least seem to be working, with a steady 3
bar output.

Arfa


Oooops ! Ignore this (except for amusement at my misfortune ... )
Accidentally posted to wrong group :-\

Arfa