I have recently fitted a Torbeck valve to a toilet cistern, but
am suffering problems with a loud 'bang' from the pipework when
it shuts off. I have checked the archives and see that this
problem has been reported before, but a strange feature of my
installation is that if I dismantle and re-assemble the valve
it remains beautifully quiet for about a day, but thereafter the
hammer gradually returns to its original ferocity.

My water feed is from a tank, and no pressure reducer is fitted.
If I restrict the flow with the service valve I can stop the
noise, but the filling rate is then much slower than with the
original ball cock.

If I can make permanent whatever I am doing by dismantling and
re-assembling the valve it will solve the problem, but I have
no idea what that is.

Richard.
http://www.rtrussell.co.uk/
To reply by email change 'news' to 'richard'

On Mon, 22 Sep 2003 13:23:50 +0000 (UTC), wrote:

My water feed is from a tank, and no pressure reducer is fitted.

Try the lower of the two supplied restrictors marked "LP" IIRC. The
bang is symptom of the valve shutting off too fast which it will do
with a high flow rate. You have to strike a balance between a reduced
flow rate and the bang.

--
Cheers
Dave. pam is missing e-mail

What I have seen being done is to add a vertical stub in the pipework that
traps air in it to provide a "shock-absorbing" function !!
Might be worth a shot for a half hours work.

Rgds
Alec
wrote in message
...
I have recently fitted a Torbeck valve to a toilet cistern, but
am suffering problems with a loud 'bang' from the pipework when
it shuts off. I have checked the archives and see that this
problem has been reported before, but a strange feature of my
installation is that if I dismantle and re-assemble the valve
it remains beautifully quiet for about a day, but thereafter the
hammer gradually returns to its original ferocity.

My water feed is from a tank, and no pressure reducer is fitted.
If I restrict the flow with the service valve I can stop the
noise, but the filling rate is then much slower than with the
original ball cock.

If I can make permanent whatever I am doing by dismantling and
re-assembling the valve it will solve the problem, but I have
no idea what that is.

Richard.
http://www.rtrussell.co.uk/
To reply by email change 'news' to 'richard'

"Alec" wrote in message
...

What I have seen being done is to add a vertical stub in the pipework that
traps air in it to provide a "shock-absorbing" function !!
Might be worth a shot for a half hours work.

Dedicated shock arrestors are available. Http://www.BES.ltd.uk Not
expensive. Just fit it on the offending pipework as close to the Torbeck as
possible.



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Dave Liquorice wrote:

: Try the lower of the two supplied restrictors marked "LP" IIRC. The
: bang is symptom of the valve shutting off too fast which it will do
: with a high flow rate. You have to strike a balance between a reduced
: flow rate and the bang.

But will that have a different effect to partially closing the service
valve ? As I said, to stop the noise I have to reduce the flow rate
so far that the fill time is unacceptable (longer than the original
ball cock, which defeats the object). I'll try the restrictor if you
think it will stop the bang at a higher flow rate, but I can't really
see why it should.

Nobody has commented on my observation that dismantling and
re-assembling the valve provides total relief from the bang for about
a day, before it gradually returns. I've done this three times now
with the same effect.

Richard.
http://www.rtrussell.co.uk/
To reply by email change 'news' to 'richard'

On Tue, 23 Sep 2003 12:38:48 +0000 (UTC), wrote:

But will that have a different effect to partially closing the
service valve ?

Donno try it. Easy enough to do...

As I said, to stop the noise I have to reduce the flow rate so far
that the fill time is unacceptable (longer than the original
ball cock, which defeats the object).

Apart from the noise most ball cocks make, though I suspect your old
ballcock may have been a low pressure one rather than high pressure
so probably not very noisy anyway.

I'll try the restrictor if you think it will stop the bang at a
higher flow rate, but I can't really see why it should.

Fluid dynamics is complicated. The flow restrictor will add a
significant amount of turbulance to the flow rather than just make the
hole through which the water has to pass smaller.

Nobody has commented on my observation that dismantling and
re-assembling the valve provides total relief from the bang for
about a day, before it gradually returns.

Presumably it's just that parts settling down into their correct
operating positions and possibly any air finally being purged out.

--
Cheers
Dave. pam is missing e-mail

I have recently fitted a Torbeck valve to a toilet cistern, but
am suffering problems with a loud 'bang' from the pipework when
it shuts off.

Fit a water hammer arrestor, such as BES #11355 (www.bes.ltd.uk). You
install it next to any problematic suddenly closing valve (i.e. Torbeck,
ceramic disc tap, washing machine). It is basically a tiny pressure
expansion vessel that is capable of absorbing the flow of water that is
moving fast, but has nowhere to go when the valve closes.

Christian.

Dave Liquorice wrote:

: But will that have a different effect to partially closing the
: service valve ?

: Donno try it. Easy enough to do...

I tried it, and the flow rate was very low. There was no evidence
that the result was any different from turning down the service valve.
I *could* have tried cutting the restrictor in half, but by then I
was losing the will to live....

So I have replaced the Torbeck with a Fluidmaster. I know that is not
without its share of problems, but it seems to have entirely solved
the banging. It is slightly more noisy when filling (largely because
of all the air bubbles) but I am very happy with it so far.

It was more difficult to fit than the Torbeck. Despite appearing to
need an identical installation, it lacks the internal 'seat' for the
service valve connector to seal against. I had to fabricate a washer
from an old grommet to make it watertight.

Thanks to those people who suggested various 'plumbing' solutions such
as adding a hammer arrestor or air spring, but my DIY skills are not
up to that level of complexity !

Richard
http://www.rtrussell.co.uk/
To reply by email change 'news' to 'news2'