Do Torbeck valves not work at very low pressure?

Reason I ask is that we just got back after a week away and the cold water tank
overflow was dribbling. Odd, I thought, as I had turned the water off before going.
It seems I hadn't turned it off completely, and a slight dribble was getting through.

But after turning the water on fully, the overflow stopped dribbling, and it's been
OK since! So the valve now seems to be functioning OK under full water pressure.

TIA

--
Andy

"Andy Pandy" wrote in message
...
Do Torbeck valves not work at very low pressure?

Reason I ask is that we just got back after a week away and the cold water
tank
overflow was dribbling. Odd, I thought, as I had turned the water off
before going.
It seems I hadn't turned it off completely, and a slight dribble was
getting through.

But after turning the water on fully, the overflow stopped dribbling, and
it's been
OK since! So the valve now seems to be functioning OK under full water
pressure.

TIA

--
Andy


Why do you turn the water off if you go away for a week if you don't when
you go out during the day?
The valve will work with whatever water pressure there is - within reason.
Maybe you need to get the main stop tap fixed first.

In article ,
"Andy Pandy" writes:
Do Torbeck valves not work at very low pressure?

Possibly not. They use the water pressure to shut off the water.
IIRC, there's a tiny let-through hole which is opened to release
the main pressure holding the valve closed. If the mains flow is
restricted such that the pressure is low with flow though the
tiny let-through hole, I could well believe it might not be able
to close off. Some of the ball-valves work the same way (but not
all).

--
Andrew Gabriel

Andrew Gabriel wrote:
In article ,
"Andy Pandy" writes:
Do Torbeck valves not work at very low pressure?

Possibly not. They use the water pressure to shut off the water.
IIRC, there's a tiny let-through hole which is opened to release
the main pressure holding the valve closed. If the mains flow is
restricted such that the pressure is low with flow though the
tiny let-through hole, I could well believe it might not be able
to close off. Some of the ball-valves work the same way (but not
all).


Same applies to the SureStop remotely operated valves. If you try to
test one by cautiously cracking an isolating valve upstream, it won't
switch off. It needs some pressure to provide the 'motive power'.


--
Ian White

On Sun, 23 Apr 2006 12:48:44 +0100, "Andy Pandy"
wrote:

Do Torbeck valves not work at very low pressure?

Reason I ask is that we just got back after a week away and the cold water tank
overflow was dribbling. Odd, I thought, as I had turned the water off before going.
It seems I hadn't turned it off completely, and a slight dribble was getting through.

But after turning the water on fully, the overflow stopped dribbling, and it's been
OK since! So the valve now seems to be functioning OK under full water pressure.

TIA


They will work over a wide pressure range. At higher pressures and
flows there is a restrictor which is a spiral gizmo that fits into the
inlet. This is to allow the valve to cope with higher pressure/flows.

The most likely reasons for what happened are that a piece of grot
entered the valve and stopped it closing against the seat properly
(unusual because normally it is flushed through), or that the
diaphragm has become stiff with age and needs to be replaced.

I would suggest turning off the water, removing the front of the valve
and then flushing the valve through in case there is more grot.

If it happens again, then try replacing the diaphragm.



--

..andy

mark wrote:
"Andy Pandy" wrote in message
...
Do Torbeck valves not work at very low pressure?

Reason I ask is that we just got back after a week away and the cold water
tank

//snip///


Why do you turn the water off if you go away for a week if you don't when
you go out during the day?

One very good reason for so doing (& likewise with other equipment) is
that if disaster strikes whilst I'm out during the day, chances are I
won't be away long or else someone will be able to track me down & I'll
be able to hotfoot it back.

If I've gone off to the ends of the earth for several days, chances are
that I'll be all but uncontactable and certainly not able to hotfoot it
back. Which could leave a 3rd party having to cope with a major
disaster such as a burst, overflow or freeze up. Certainly more cost,
more intrusion.....

"mark" wrote in message
news
Why do you turn the water off if you go away for a week if you don't when
you go out during the day?

Because a slow leak has the potential to do a lot more damage in a week than over a
few hours.

A couple of years ago my toilet tank started leaking, the valve was faulty and was
letting drips through, and the water was leaking out of the flush handle joint, which
wasn't sealed properly and was at a lower level than the overflow pipe. I noticed a
pool of water on the floor after getting back from work, no damage, but if I had been
away for a week it could have caused some damage.

The valve will work with whatever water pressure there is - within reason.
Maybe you need to get the main stop tap fixed first.

Been experimenting - just need to turn it off a bit tighter.

--
Andy

"Andy Hall" wrote in message
...
Do Torbeck valves not work at very low pressure?

Reason I ask is that we just got back after a week away and the cold water tank
overflow was dribbling. Odd, I thought, as I had turned the water off before
going.
It seems I hadn't turned it off completely, and a slight dribble was getting
through.

But after turning the water on fully, the overflow stopped dribbling, and it's
been
OK since! So the valve now seems to be functioning OK under full water pressure.

TIA


They will work over a wide pressure range. At higher pressures and
flows there is a restrictor which is a spiral gizmo that fits into the
inlet. This is to allow the valve to cope with higher pressure/flows.

Yup - fitted one of these.

The most likely reasons for what happened are that a piece of grot
entered the valve and stopped it closing against the seat properly
(unusual because normally it is flushed through),

That would make sense - it might not have been flushed through because of the very
slow flow rate. On turning the full water pressure on, it would have been flushed
through.

or that the
diaphragm has become stiff with age and needs to be replaced.

It's only a year old...

I would suggest turning off the water, removing the front of the valve
and then flushing the valve through in case there is more grot.

Well it's OK now so I guess any grot has already been flushed through.

If it happens again, then try replacing the diaphragm.

Thanks - I'll keep my eye on it...

--
Andy

In article , Andy Pandy spam8times@wonde
rful.spam.invalid writes

"mark" wrote in message
news
Why do you turn the water off if you go away for a week if you don't when
you go out during the day?

Because a slow leak has the potential to do a lot more damage in a week than
over a
few hours.

A couple of years ago my toilet tank started leaking, the valve was faulty and
was
letting drips through, and the water was leaking out of the flush handle joint,
which
wasn't sealed properly and was at a lower level than the overflow pipe. I
noticed a
pool of water on the floor after getting back from work, no damage, but if I had
been
away for a week it could have caused some damage.

The valve will work with whatever water pressure there is - within reason.
Maybe you need to get the main stop tap fixed first.

Been experimenting - just need to turn it off a bit tighter.

--
Andy

There's a gizmo called a pipeguard for folk worried about pipes
bursting, leaks etc, it detects abnormal flow and shuts the water off.

--
David