Last Saturday, I spoke to the man behind the counter, of the place where
I am going to buy my wash hand basin and loo. He tells me that the
modern quarter turn taps can be difficult when supplied with low
pressure water. Water getting from the hot supply to the cold, or the
other way round.
A plumber told me today, that they should work fine on tank fed water.

Who do I believe?

Dave

On Tue, 7 Feb 2006 18:51:56 +0000 (UTC), Dave wrote:

A plumber told me today, that they should work fine on tank fed water.

They will work, but unless you have a good head, the flow may not be
very good - some don't open as far as conventional taps.

The bit about hot & cold mixing is nonsense, unless your feeds are at
different pressures.

--
Nigel M

Nigel Molesworth wrote:
On Tue, 7 Feb 2006 18:51:56 +0000 (UTC), Dave wrote:


A plumber told me today, that they should work fine on tank fed water.


They will work, but unless you have a good head, the flow may not be
very good - some don't open as far as conventional taps.

OK on that. I can understand it if the orifice is smaller than the taps
I have been used to. Kitchen mixer is much the same, but this tap is fed
from a smaller bore pipe than usual.

The bit about hot & cold mixing is nonsense, unless your feeds are at
different pressures.

I didn't like to press this home, as I had just agreed £27-00 discount
per set from him :-)

Dave

On Tue, 7 Feb 2006 22:27:16 +0000 (UTC), Dave wrote:

Kitchen mixer is much the same, but this tap is fed
from a smaller bore pipe than usual.

Kitchen taps are generally not "mixers" they just look like them.
Normally the water goes up separate channels to the spout.

--
Nigel M

In an earlier contribution to this discussion,
Dave wrote:

Last Saturday, I spoke to the man behind the counter, of the place
where I am going to buy my wash hand basin and loo. He tells me that
the modern quarter turn taps can be difficult when supplied with low
pressure water. Water getting from the hot supply to the cold, or the
other way round.
A plumber told me today, that they should work fine on tank fed water.

Who do I believe?

Dave

Some modern taps have very poor flow rates when fed with tank pressure
rather than mains pressure.

If you're feeding a tap with cold water at mains pressure and hot water at
tank pressure, it's important that the hot and cold have independent paths
all the way to the discharge nozzle - rather than mixing further back in the
tap. Maybe this was what the man behind the counter was saying? If the
mixing takes place further back, the mains pressure cold can push the low
pressure hot *backwards* up the feed pipe. I think you're supposed to fit
double check valves to prevent that sort of thing anyway - but I'm not sure
how many people do!
--
Cheers,
Roger
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Dave wrote:

Last Saturday, I spoke to the man behind the counter, of the place where
I am going to buy my wash hand basin and loo. He tells me that the
modern quarter turn taps can be difficult when supplied with low
pressure water. Water getting from the hot supply to the cold, or the
other way round.
A plumber told me today, that they should work fine on tank fed water.

Who do I believe?

I have seen quarter turn taps that dripped when turned off holding back
low presure tank fed water. However once the pressure was raised (shower
pump) they shut off perfectly.


--
Cheers,

John.

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John Rumm wrote:
I have seen quarter turn taps that dripped when turned off holding back
low presure tank fed water. However once the pressure was raised (shower
pump) they shut off perfectly.



FWIW I've a quarter turn tap which is the exact opposite1

Regards
Capitol

Roger Mills (aka Set Square) wrote:

Some modern taps have very poor flow rates when fed with tank pressure
rather than mains pressure.

Noted, thanks.

If you're feeding a tap with cold water at mains pressure and hot water at
tank pressure, it's important that the hot and cold have independent paths
all the way to the discharge nozzle - rather than mixing further back in the
tap. Maybe this was what the man behind the counter was saying?

That sounds about right from memory.

If the
mixing takes place further back, the mains pressure cold can push the low
pressure hot *backwards* up the feed pipe. I think you're supposed to fit
double check valves to prevent that sort of thing anyway - but I'm not sure
how many people do!

The counter man mentioned this as well.
Many thanks for your input to my question. It looks like I will have to
as at the plumbing supplier.

Regards

Dave