High pressure vs. low pressure ball valves.
p_te...@yahoo.co.uk
The ball valve in our cold water header tank seems to be causing some
knocking and
generally seems to be due for a change (intermittent overflow for
example). In my local
B&Q there are two varieties of valve: high and low pressure. My
Collin's DIY manual gives
no guidance on this subject so I'm wondering if there is some decisive
factor in which to use.
The house is a normal two storey semi with a good mains pressure.
Thanks in advance for any advice,
Peter.
Roger Mills
p_te...@yahoo.co.uk <p_te...@yahoo.co.uk> wrote:
High pressure are for mains input - as your header tank will be. Low
pressure are for toilets etc. fed by gravity from header tanks rather than
being directly connected to the mains.
Many modern torbeck-type valves are suitable for either - and are supplied
with 2 or more flow restrictors. You fit the appropriate restrictor
depending on the supply pressure.
--
Cheers,
Roger
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Andy Hall
<p_te...@yahoo.co.uk> wrote:
Low pressure types are intended for toilets etc. that are filled from
the roof tank.
For the mains feed to the roof tank, a high pressure valve should be
used unless the mains pressure is really low.
Since you are changing, it would be a good opportunity to fit an
equilibrium float valve such as a Torbeck.
These are quite inexpensive and as well as operating a lot more
quietly than the traditional Portsmouth type, have a clean shut off.
--
.andy
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Guy King
from Andy Hall <an...@hall.nospam> contains these words:
> These are quite inexpensive and as well as operating a lot more
> quietly than the traditional Portsmouth type, have a clean shut off.
The potential drawback is that where previously you may not have had any
resonance as the valve shuts, with a Torbeck type valve you sometimes
get a mighty slam as it closes. It's down to loose pipework, and isn't
really the fault of the valve, but it's often a bastard to track down
where it's loose.
--
Skipweasel
Pay no attention to that man behind the curtain.
Ed Sirett
> In an earlier contribution to this discussion,
> p_te...@yahoo.co.uk <p_te...@yahoo.co.uk> wrote:
>
>> Hi,
>> The ball valve in our cold water header tank seems to be causing some
>> knocking and
>> generally seems to be due for a change (intermittent overflow for
>> example). In my local
>> B&Q there are two varieties of valve: high and low pressure. My
>> Collin's DIY manual gives
>> no guidance on this subject so I'm wondering if there is some decisive
>> factor in which to use.
>> The house is a normal two storey semi with a good mains pressure.
>> Thanks in advance for any advice,
>> Peter.
>
> High pressure are for mains input - as your header tank will be. Low
> pressure are for toilets etc. fed by gravity from header tanks rather than
> being directly connected to the mains.
>
> Many modern torbeck-type valves are suitable for either - and are supplied
> with 2 or more flow restrictors. You fit the appropriate restrictor
> depending on the supply pressure.
Likewise the bog standard diaphragm type float valve only differs in the
size of the nozzle (white for high pressure with about a 3mm hole and red
for low pressure with about an 8mm hole).
--
Ed Sirett - Property maintainer and registered gas fitter.
The FAQ for uk.diy is at http://www.diyfaq.org.uk
Gas fitting FAQ http://www.makewrite.demon.co.uk/GasFitting.html
Sealed CH FAQ http://www.makewrite.demon.co.uk/SealedCH.html
Choosing a Boiler FAQ http://www.makewrite.demon.co.uk/BoilerChoice.html
p_te...@yahoo.co.uk
Thanks to everyone who replied. It's really very much appreciated.
Time to don my waders I guess :^)
Cheers,
Peter.
Chris Bacon
It's mains pressure, so use the high-pressure cone. The low
pressure ones are for gravity-fed stuff (e.g. the bathroom WC).