Hello,

Possibly this is a daft question but here goes...

Can you fit more than one ball cock to a water tank?

I ask because a couple of years ago I bought a new 50 gallon (IIRC)
tank and it came with two ball cocks. At the time I thought there had
been a mistake at the warehouse and they had put two in by mistake.
The instructions only mentioned fitting one, so that's what I did.

However, I am sure I read on this group, a post by someone who had
fitted two ball cocks so that his tank filled up faster. I wonder
whether my instructions only mentioned one valve because the same
instructions would have been sent with tanks of all sizes and the
smaller tanks would only have needed one valve?

Does a second valve mean the tank fills twice as fast? I'm wondering
whether two valves on the same pipe mean that the tank fills at the
same speed as before and the flow is shared between them? IE the water
is half the speed out of each?

The pipe work to the tank is 15mm; if I add a second valve will it
make any difference or will the 15mm pipe limit the maximum flow?

Thanks,
Stephen.

In an earlier contribution to this discussion,
Stephen wrote:

Hello,

Possibly this is a daft question but here goes...

Can you fit more than one ball cock to a water tank?

I ask because a couple of years ago I bought a new 50 gallon (IIRC)
tank and it came with two ball cocks. At the time I thought there had
been a mistake at the warehouse and they had put two in by mistake.
The instructions only mentioned fitting one, so that's what I did.

However, I am sure I read on this group, a post by someone who had
fitted two ball cocks so that his tank filled up faster. I wonder
whether my instructions only mentioned one valve because the same
instructions would have been sent with tanks of all sizes and the
smaller tanks would only have needed one valve?

Does a second valve mean the tank fills twice as fast? I'm wondering
whether two valves on the same pipe mean that the tank fills at the
same speed as before and the flow is shared between them? IE the water
is half the speed out of each?

The pipe work to the tank is 15mm; if I add a second valve will it
make any difference or will the 15mm pipe limit the maximum flow?

Thanks,
Stephen.

You might get a *bit* more flow - but certainly nothing like twice the
original flow - because it all still has to come through the single 15mm
pipe.
--
Cheers,
Roger
______
Email address maintained for newsgroup use only, and not regularly
monitored.. Messages sent to it may not be read for several weeks.
PLEASE REPLY TO NEWSGROUP!

"Roger Mills" wrote

You might get a *bit* more flow - but certainly nothing like twice the
original flow - because it all still has to come through the single 15mm
pipe.
--
Have to disagree here!
My father-in-law did just this (added a second ball valve on a 15mm tank
feed).
His shower was draining the tank faster than the ball valve could fill it,
so he fitted a second one.
A lot of these ball valves have a reduced internal nozzle which will reduce
flow significantly even on a 15mm feed.

Try it - it won't cost big bucks, but make sure you measure the fill rate
(by rough check of the tank level change) with one valve open, then with 2
valves open.

HTH

Phil

On Thu, 08 Jan 2009 14:03:16 +0000, Stephen wrote:

Hello,

Possibly this is a daft question but here goes...

Can you fit more than one ball cock to a water tank?

I ask because a couple of years ago I bought a new 50 gallon (IIRC) tank
and it came with two ball cocks. At the time I thought there had been a
mistake at the warehouse and they had put two in by mistake. The
instructions only mentioned fitting one, so that's what I did.

However, I am sure I read on this group, a post by someone who had
fitted two ball cocks so that his tank filled up faster. I wonder
whether my instructions only mentioned one valve because the same
instructions would have been sent with tanks of all sizes and the
smaller tanks would only have needed one valve?

Does a second valve mean the tank fills twice as fast? I'm wondering
whether two valves on the same pipe mean that the tank fills at the same
speed as before and the flow is shared between them? IE the water is
half the speed out of each?

The pipe work to the tank is 15mm; if I add a second valve will it make
any difference or will the 15mm pipe limit the maximum flow?


With typical mains pressure and tank location etc I would expect that
you'll get the better part of twice the flow rate. If however there is
problem with the supply pressure then a second ball cock won't sort
things.




--
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

TheScullster wrote:
A lot of these ball valves have a reduced internal nozzle which will reduce
flow significantly even on a 15mm feed.

The one I was pulling apart the other day - and I think every one I've
ever seen - has a nozzle of maybe 4mm squirting water against a rubber
diaphragm a few mm away. It will be the limiting factor, not the pipe.

That's why they supply 2 nozzles - a fatter one for low pressure (from
tank) supplies.

Andy

On 8 Jan, 14:03, Stephen wrote:
Can you fit more than one ball cock to a water tank?

Yes, but why would you want to?

Cold water tanks are there as a reserve supply of water, so you don't
really care how long they take to re-fill. Toilet cisterns are there
for immediate use, so you do care. If it's a cistern, then fit a
different _type_ of valve (Torbeck etc.) that fills with the full flow
rate all the way, then shuts quickly, rather than the traditional old
Croydon float valves that closed gradually.

In an earlier contribution to this discussion,
Stephen wrote:

The tip about the overflow is a good one.


Maybe. But *both* valves would have to fail open before you needed the extra
overflow capacity - which ain't all that likely.
--
Cheers,
Roger
______
Email address maintained for newsgroup use only, and not regularly
monitored.. Messages sent to it may not be read for several weeks.
PLEASE REPLY TO NEWSGROUP!

On Tue, 13 Jan 2009 03:55:57 -0800 (PST), Andy Dingley
wrote:

Can you fit more than one ball cock to a water tank?

Yes, but why would you want to?

Perhaps our posts crossed?

"the pipes whistle for hours when the tank fills up, so I'd like it to
fill faster and go silent sooner." (edited to read better than
before!)

Re. the overflows: would you need one 21mm pipes for each ball cock or
could one manage? I thought that both failing together would be
unlikely but for the cost of a pipe against the cost of a new roof, it
doesn't seem worth taking the risk.

The only problem would be crawling to poke another pipe through the
eaves. Could I be naughty and tee a second overflow into the CH
overflow pipe. What's the likelihood of all three valves (2 in water,
one in CH) failing together?

OTOH, I think I've talked myself out of that: I suppose there's a very
slim possibility of contamination working from the CH header tank up
the overflow to the HW tank, so I guess it's against regs and I shan't
do it.

I did start a new thread but no-one seems to have noticed ;(

I was going to add a second ball cock and see what difference it made
but I am confused about type 1 and type 2 valves. I have searched
google but the sites seem to contradict each other. What are type 1
and type 2 and which is used where?

Thanks.

TheScullster wrote:
"Roger Mills" wrote

You might get a *bit* more flow - but certainly nothing like twice the
original flow - because it all still has to come through the single 15mm
pipe.
--
Have to disagree here!
My father-in-law did just this (added a second ball valve on a 15mm tank
feed).
His shower was draining the tank faster than the ball valve could fill it,
so he fitted a second one.
A lot of these ball valves have a reduced internal nozzle which will reduce
flow significantly even on a 15mm feed.

Try it - it won't cost big bucks, but make sure you measure the fill rate
(by rough check of the tank level change) with one valve open, then with 2
valves open.


Could also try using fluidmaster type float valves. They only ever open at
full flow rate and then maintain full flow until full, whereas a typical ball
valve will turn on and off gradually according to the position of the ball.
With a normal ballcock valve the tank could be half empty before the water
supply is at full flow to refill it.

In article ,
Stephen wrote:
I was going to add a second ball cock and see what difference it made
but I am confused about type 1 and type 2 valves. I have searched
google but the sites seem to contradict each other. What are type 1
and type 2 and which is used where?

Perhaps working pressure? A header tank would normally come from the mains
but older toilets using this sort of valve might be fed from that tank so
low pressure.

FWIW, they're normally called float valves these days.

--
*You are validating my inherent mistrust of strangers

Dave Plowman London SW
To e-mail, change noise into sound.

On Thu, 22 Jan 2009 13:53:26 +0000, chunkyoldcortina
wrote:

Could also try using fluidmaster type float valves.

Can you get these for water tanks? I've only ever seen them for toilet
cisterns.

Thanks.

On Thu, 22 Jan 2009 15:50:27 +0000 (GMT), "Dave Plowman (News)"
wrote:

FWIW, they're normally called float valves these days.

Is that for reasons of political correctness?

In an earlier contribution to this discussion,
Stephen wrote:

On Thu, 22 Jan 2009 13:53:26 +0000, chunkyoldcortina
wrote:

Could also try using fluidmaster type float valves.

Can you get these for water tanks? I've only ever seen them for toilet
cisterns.

Thanks.

I see no reason why a side-entry valve intended for a cistern wouldn't work
on a water tank - provided the overflow pipe isn't a lot lower than the
entry pipe. If it is, the tank will overflow before the water level reaches
the float!
--
Cheers,
Roger
______
Email address maintained for newsgroup use only, and not regularly
monitored.. Messages sent to it may not be read for several weeks.
PLEASE REPLY TO NEWSGROUP!

Stephen wrote:
On Thu, 22 Jan 2009 13:53:26 +0000, chunkyoldcortina
wrote:

Could also try using fluidmaster type float valves.

Can you get these for water tanks? I've only ever seen them for toilet
cisterns.

http://www.screwfix.com/prods/85797/...%20Valve%20%22

http://www.screwfix.com/prods/49003/...o%2 03%2F8%22

Depending on size required.

I think the torbeck ones work the same way (as in full on/full off only)

http://www.screwfix.com/prods/14716/...-Cistern-Valve

On Fri, 23 Jan 2009 14:57:24 -0000, "Roger Mills"
wrote:

I see no reason why a side-entry valve intended for a cistern wouldn't work
on a water tank - provided the overflow pipe isn't a lot lower than the
entry pipe. If it is, the tank will overflow before the water level reaches
the float!

Thank you. These always seem to be advertised for toilets so I thought
they were only for toilets and that there was a reason they could not
be used on water tanks, perhaps regulatory rather than technical.
However I guess it's just that they sell more to people for toilets
and that is why they are marketed as such. I see the SF description of
one of the links given in the other reply does say for both toilets
and tanks. Thanks.

On Jan 28, 8:39*pm, Stephen wrote:
On Fri, 23 Jan 2009 14:57:24 -0000, "Roger Mills"

wrote:
I see no reason why a side-entry valve intended for a cistern wouldn't work
on a water tank - provided the overflow pipe isn't a lot lower than the
entry pipe. If it is, the tank will overflow before the water level reaches
the float!

Thank you. These always seem to be advertised for toilets so I thought
they were only for toilets and that there was a reason they could not
be used on water tanks, perhaps regulatory rather than technical.
However I guess it's just that they sell more to people for toilets
and that is why they are marketed as such. I see the SF description of
one of the links given in the other reply does say for both toilets
and tanks. Thanks.