Hi All,

I want to change the ballcock on my cold water header tank in the roof with
the objective of getting greater flow. This is because my hot warter system
can drain the tank quicker than the mains can refil it.
The feed pipe is 15mm and not practical to increase to 22mm but the orifice
inside the ball valve is very scaled but even so is only about 4mm bore
which must limit the flow severely ( much more than 15mm supply pipe(?)

I see there are four types of metal ball valves all to BS1212
Part1 - like 1 already have and part 2 with a lever with a right angle bend
at the ball end which rather looks like it woul reduce the operating level
in the tank - not good for my problem anyway
Each type is available as high and low pressure options.

My mains pressure is about 2.5-3 bar. - we live on a hill top

I have been unable to find a reference as to the pressure range of each type
of valve only a suggestion that older part 1 valves ought to be replaced
with part 2 versions - http://davidkearns.co.uk/plumbingtips.asp (so why are
both types still sold?? I'm tempted to ask)

I assume that a low pressure valve part1 or Part 2 would have a larger
orifice and hence better flow.

Can i use a 'low pressure' valve on my relatively low mains water pressure.

NB I do not want to use a plastic Fordham type valve as I have had numerous
problems with these in toilet cisterns over the years and the diaphragms do
not seem to last long at all.

Happy New Year

Bob

Go to your merchants and buy a larger orifice to replace the one you have

"Bob Minchin" wrote in message
...
Hi All,

I want to change the ballcock on my cold water header tank in the roof
with
the objective of getting greater flow. This is because my hot warter
system
can drain the tank quicker than the mains can refil it.
The feed pipe is 15mm and not practical to increase to 22mm but the
orifice
inside the ball valve is very scaled but even so is only about 4mm bore
which must limit the flow severely ( much more than 15mm supply pipe(?)

I see there are four types of metal ball valves all to BS1212
Part1 - like 1 already have and part 2 with a lever with a right angle
bend
at the ball end which rather looks like it woul reduce the operating level
in the tank - not good for my problem anyway
Each type is available as high and low pressure options.

My mains pressure is about 2.5-3 bar. - we live on a hill top

I have been unable to find a reference as to the pressure range of each
type
of valve only a suggestion that older part 1 valves ought to be replaced
with part 2 versions - http://davidkearns.co.uk/plumbingtips.asp (so why
are
both types still sold?? I'm tempted to ask)

I assume that a low pressure valve part1 or Part 2 would have a larger
orifice and hence better flow.

Can i use a 'low pressure' valve on my relatively low mains water
pressure.

NB I do not want to use a plastic Fordham type valve as I have had
numerous
problems with these in toilet cisterns over the years and the diaphragms
do
not seem to last long at all.

Happy New Year

Bob

ski wrote in message ...
Go to your merchants and buy a larger orifice to replace the one you have

"Bob Minchin" wrote in message
...
Hi All,

I want to change the ballcock on my cold water header tank in the roof
with
the objective of getting greater flow. This is because my hot warter
system
can drain the tank quicker than the mains can refil it.
The feed pipe is 15mm and not practical to increase to 22mm but the
orifice
inside the ball valve is very scaled but even so is only about 4mm bore
which must limit the flow severely ( much more than 15mm supply pipe(?)

I see there are four types of metal ball valves all to BS1212
Part1 - like 1 already have and part 2 with a lever with a right angle
bend
at the ball end which rather looks like it woul reduce the operating
level
in the tank - not good for my problem anyway
Each type is available as high and low pressure options.

My mains pressure is about 2.5-3 bar. - we live on a hill top

I have been unable to find a reference as to the pressure range of each
type
of valve only a suggestion that older part 1 valves ought to be replaced
with part 2 versions - http://davidkearns.co.uk/plumbingtips.asp (so why
are
both types still sold?? I'm tempted to ask)

I assume that a low pressure valve part1 or Part 2 would have a larger
orifice and hence better flow.

Can i use a 'low pressure' valve on my relatively low mains water
pressure.

NB I do not want to use a plastic Fordham type valve as I have had
numerous
problems with these in toilet cisterns over the years and the diaphragms
do
not seem to last long at all.

Happy New Year

Bob





Thanks Ski,

I did not realise that other sizes would be available as loose items.

Bob

On Fri, 31 Dec 2004 16:06:54 GMT, "Bob Minchin"
wrote:

Hi All,

I want to change the ballcock on my cold water header tank in the roof with
the objective of getting greater flow. This is because my hot warter system
can drain the tank quicker than the mains can refil it.
The feed pipe is 15mm and not practical to increase to 22mm but the orifice
inside the ball valve is very scaled but even so is only about 4mm bore
which must limit the flow severely ( much more than 15mm supply pipe(?)

I see there are four types of metal ball valves all to BS1212
Part1 - like 1 already have and part 2 with a lever with a right angle bend
at the ball end which rather looks like it woul reduce the operating level
in the tank - not good for my problem anyway
Each type is available as high and low pressure options.

My mains pressure is about 2.5-3 bar. - we live on a hill top

I have been unable to find a reference as to the pressure range of each type
of valve only a suggestion that older part 1 valves ought to be replaced
with part 2 versions - http://davidkearns.co.uk/plumbingtips.asp (so why are
both types still sold?? I'm tempted to ask)

I assume that a low pressure valve part1 or Part 2 would have a larger
orifice and hence better flow.

Can i use a 'low pressure' valve on my relatively low mains water pressure.

You can try. The effect if the pressure is too high for it can be
water hammer as the valve is closing.



NB I do not want to use a plastic Fordham type valve as I have had numerous
problems with these in toilet cisterns over the years and the diaphragms do
not seem to last long at all.

I've had good results with both Torbeck and Fluidmaster valves.

Another approach that you can try, that I've done with a pair of
Torbecks (could be done with any valves), is to fit two valves. This
has quite a dramatic effect on the flow.



--

..andy

To email, substitute .nospam with .gl

Bob Minchin wrote:
Hi All,

I want to change the ballcock on my cold water header tank in the roof with
the objective of getting greater flow. This is because my hot warter system
can drain the tank quicker than the mains can refil it.

Are "full bore" ballcocks available?
I'm imagining a quarter turn ballcock, with a 10:1 lever system, and
a bit of hysterisis. (sp?)

In article ,
Bob Minchin wrote:

I did not realise that other sizes would be available as loose
items.

Yes, I was in one of the sheds buying a new toilet ballcock
assembly just the other day. They also packets of ballcock
refurb parts. There were two nozzles in there, for high
pressure and low pressure..... quite a difference in the
hole diameter.

--
Tony Williams.

On Fri, 31 Dec 2004 23:18:07 +0000, Ian Stirling wrote:

Bob Minchin wrote:
Hi All,

I want to change the ballcock on my cold water header tank in the roof with
the objective of getting greater flow. This is because my hot warter system
can drain the tank quicker than the mains can refil it.

Are "full bore" ballcocks available?
I'm imagining a quarter turn ballcock, with a 10:1 lever system, and
a bit of hysterisis. (sp?)

Firstly I think you should exhaust all the posibilites of poor
flow/pressure in the mains.

If the _flow_ is poor due to poor _pressure_ then replacing the
white high pressure nozzel in the standard ball cock with a red low
pressure unit will help. If the standing pressure is high though the red
ones may not shut off 100%.

Rather cheaper than replacing the ball cock with the next size up (the
price between each size up seems to be x3). Is add another unit is
parallel.

Is the tank being emptied because you have a serious pumped shower?
In which case you may simply need to have greater capacity or more frugal
usage.


--
Ed Sirett - Property maintainer and registered gas fitter.
The FAQ for uk.diy is at 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

In article , ski
wrote:

Go to your merchants and buy a larger orifice to replace the one you have

What merchants?
What orifice?

See if this helps:

http://www.allmyfaqs.com/faq.pl?How_to_post

--
AJL Electronics (G6FGO) Ltd : Satellite and TV aerial systems
http://www.classicmicrocars.co.uk : http://www.ajlelectronics.co.uk