Hi,

Just got my 27 litre feed+expansion tank, which is long and slim to fit in
the available space.

27 litres is on the small side of just about big enough - calculated
expansion is about 10 litres (upto 80C working temp on 350 litre system)
and might go as far as 15 litres if the system boiled (though at that point
I care little if it starts going out the overflow).

On my tank this equates to about 10cm height gain in the water level in the
tank going from cold to hot. Nominal cold water level will be set at aroun
8-10cm giving a working height of about 18-20cm which seems about right for
mounting the valve and overflow.

So I don't want to use a normal arm ballcock - too much rotation stress as
the ball will end up submerged at some point. I'm sure the tank will cope,
but it seems bad to engineer excessive stresses in when it's avoidable.

So the obvious answer is a vertical float valve. But which one.

Choice seems to mostly be

Torbeck side inlet : part number 18198 on
http://www.bes.co.uk/products/120.asp

Or Fluidmaster, part 15887 on same page.

Any pros or cons with either make?

Are there any other makes?

Cheers

Tim

On 11 May, 15:55, Tim S wrote:

Any pros or cons with either make?

Are there any other makes?

Yes. They're not rated for boiling water, which is why they're not
used on F&E tanks.

Onetap coughed up some electrons that declared:

On 11 May, 15:55, Tim S wrote:

Any pros or cons with either make?

Are there any other makes?

Yes. They're not rated for boiling water, which is why they're not
used on F&E tanks.

Oh.

Any other suggestions, or am I back to brass ballcocks?

I could put a metal reinforcing plate behind the valve inlet. The tank is
GRP so it's pretty strong, but like I said, no point in over stressing
it...

Ta

Tim

Tim S coughed up some electrons that declared:

Onetap coughed up some electrons that declared:

On 11 May, 15:55, Tim S wrote:

Any pros or cons with either make?

Are there any other makes?

Yes. They're not rated for boiling water, which is why they're not
used on F&E tanks.

Oh.

Any other suggestions, or am I back to brass ballcocks?

I could put a metal reinforcing plate behind the valve inlet. The tank is
GRP so it's pretty strong, but like I said, no point in over stressing
it...

Ta

Tim

Although another thought comes to mind... I was going to stick a little
electric level sensor in too - as a boiler cutoff should the tank run dry
(eg system has a minor leak and the mains water is off, like when we're on
holiday). Plenty of those in RS for surprisingly reasonable money.

I could just as well use that signal to drive an electric water valve to
fill it...

In fact that's a very good idea... Depending on the level sensor I might
even get down to only two holes in the tank - outlet and overflow. Fill
could be direct through lid and level sensor could be top mounted depending
on type.

Being a GRP tank (and not cheap), I relish not the prospect of drilling any
more holes than necessary...

I like this idea...

Cheers

Tim

On Mon, 11 May 2009 16:08:27 +0100, Tim S wrote:

Any other suggestions, or am I back to brass ballcocks?

I could put a metal reinforcing plate behind the valve inlet. The tank is
GRP so it's pretty strong, but like I said, no point in over stressing
it...

Yes, it's proper practice to put in a metal reinforcing plate. And brass
ball'ocks is the way to go IMHO :-)


--
John Stumbles -- http://yaph.co.uk

Bob the builder / it'll cost 'yer
Bob the builder / loadsa dosh

YAPH coughed up some electrons that declared:

On Mon, 11 May 2009 16:08:27 +0100, Tim S wrote:

Any other suggestions, or am I back to brass ballcocks?

I could put a metal reinforcing plate behind the valve inlet. The tank is
GRP so it's pretty strong, but like I said, no point in over stressing
it...

Yes, it's proper practice to put in a metal reinforcing plate. And brass
ball'ocks is the way to go IMHO :-)



Thank you John. I was looking through RS thinking, hmm solonoid valves are
cheap, so are optical level sensors (20 quid). But I was also thinking
about the poor sod who might have to maintain this in the future and the
fact that I have to wire a load of stuff with a relay and a PSU up before I
can even get water in...

Do you reckon a fully submerged ball (at final temperature) is likely to
cause me any problems in terms of strain?

Cheers

Tim

On Mon, 11 May 2009 21:25:20 +0100, Tim S wrote:

Do you reckon a fully submerged ball (at final temperature) is likely to
cause me any problems in terms of strain?

Any float ball in a well set up system is liable to be operating fully
submerged at maximum expansion. Shouldn't be a problem. If you're
expecting the header to run hot much of the time you might fit a copper
rather than plastic ball (I think BES do them). Probably ought to be
fitted on all systems but more observed in the breach.



--
John Stumbles -- http://yaph.co.uk

Press any key to continue or any other key to exit

YAPH coughed up some electrons that declared:

On Mon, 11 May 2009 21:25:20 +0100, Tim S wrote:

Do you reckon a fully submerged ball (at final temperature) is likely to
cause me any problems in terms of strain?

Any float ball in a well set up system is liable to be operating fully
submerged at maximum expansion. Shouldn't be a problem. If you're
expecting the header to run hot much of the time you might fit a copper
rather than plastic ball (I think BES do them). Probably ought to be
fitted on all systems but more observed in the breach.


Thanks John, that's put my mind at rest. The one known factor with a
ballcock is I *can* bend the arm to get any desired level (in this case,
cold level needs to be as low as possible).

Excellent - can order the parts now - cheers.

Tim

"Tim S" wrote in message
...
YAPH coughed up some electrons that declared:

On Mon, 11 May 2009 16:08:27 +0100, Tim S wrote:

Any other suggestions, or am I back to brass ballcocks?

I could put a metal reinforcing plate behind the valve inlet. The tank
is
GRP so it's pretty strong, but like I said, no point in over stressing
it...

Yes, it's proper practice to put in a metal reinforcing plate. And brass
ball'ocks is the way to go IMHO :-)



Thank you John. I was looking through RS thinking, hmm solonoid valves are
cheap, so are optical level sensors (20 quid). But I was also thinking
about the poor sod who might have to maintain this in the future and the
fact that I have to wire a load of stuff with a relay and a PSU up before
I
can even get water in...

Do you reckon a fully submerged ball (at final temperature) is likely to
cause me any problems in terms of strain?

Cheers

Tim

I had never thought about the stresses on a tank wall due to the ball valve
being submerged. I have experienced the washer getting really crushed due to
this excessive pressure on the lever arm. Surely a better design is called
for which will withstand such forces better. I personally don't like the
split pin used on the old style brass ball valves - surely a weak link.

In article ,
"John" writes:
I had never thought about the stresses on a tank wall due to the ball valve
being submerged. I have experienced the washer getting really crushed due to
this excessive pressure on the lever arm. Surely a better design is called
for which will withstand such forces better.

Sealed system?

I personally don't like the
split pin used on the old style brass ball valves - surely a weak link.

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]

"Andrew Gabriel" wrote in message
...
In article ,
"John" writes:
I had never thought about the stresses on a tank wall due to the ball
valve
being submerged. I have experienced the washer getting really crushed due
to
this excessive pressure on the lever arm. Surely a better design is
called
for which will withstand such forces better.

Sealed system?

I personally don't like the
split pin used on the old style brass ball valves - surely a weak link.

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]

Agreed

On 12 May, 10:07, Tim S wrote:

The plastic floats on ball valves to the relevant BS will withstand
boiling water. Copper ones are a PITA.
The electronic level systems I've seen had at least 2 electrodes; low,
water on and high, water off. ISTR they also had additional high-high
and low-low sensors to shut off the plant and/or operate an alarm.

Solenoid valves aren't reliable for water shutting off (except washing
machine ones, for some reason). They're usually solenoid-operated
pilot valves that operate a diaphragm valve. The only one I ever used
for water shutting-off duties (a 28mm job) failed and was replaced
with an electric powered ball valve. I think the small washing machine
type are just solenoid types, but don't know the details.

The ony other variation I've seen on this was a tiny ball float valve
which operated a 6" diaphragm valve outside the tank. It was a delayed
action thing, the water was off or 100% on, no trickling through a
partially open float valve. The little float valve exerted or released
pressure on the upstream side of the diaphragm, the same principle as
combi diaphragm valves. The pipes from the float valve to diaphragm
valve were 1/4". It was an American-made thing by that lot that make
water softener valves for every softener manufacturer, Aqua summat. It
worked really well but baffled every plumber who saw it.

Onetap coughed up some electrons that declared:

On 12 May, 10:07, Tim S wrote:

The plastic floats on ball valves to the relevant BS will withstand
boiling water. Copper ones are a PITA.

Ta - I'll look into this too...

The electronic level systems I've seen had at least 2 electrodes; low,
water on and high, water off. ISTR they also had additional high-high
and low-low sensors to shut off the plant and/or operate an alarm.

I guess that will be for hysteresis - to prevent random wibblings.

I was looking at optical sensors - the internal reflection type.

Solenoid valves aren't reliable for water shutting off (except washing
machine ones, for some reason). They're usually solenoid-operated
pilot valves that operate a diaphragm valve. The only one I ever used
for water shutting-off duties (a 28mm job) failed and was replaced
with an electric powered ball valve.

Do you have a lead for the electric ball valve? Or was it just a regular
zone valve? I'm looking for something to control rads with (15mm would be
OK). Cheapest 24v (I really want 12v, but 24 is OK, mains is not) solution
seems to be a thermal wax valve, but as the valves will go in the roof
voids, I'm free to use anything.

I think the small washing machine
type are just solenoid types, but don't know the details.

The ony other variation I've seen on this was a tiny ball float valve
which operated a 6" diaphragm valve outside the tank. It was a delayed
action thing, the water was off or 100% on, no trickling through a
partially open float valve. The little float valve exerted or released
pressure on the upstream side of the diaphragm, the same principle as
combi diaphragm valves. The pipes from the float valve to diaphragm
valve were 1/4". It was an American-made thing by that lot that make
water softener valves for every softener manufacturer, Aqua summat. It
worked really well but baffled every plumber who saw it.

That's interesting - thanks

Cheers

Tim

On Tue, 12 May 2009 22:55:28 +0100, Tim S wrote:

Do you have a lead for the electric ball valve? Or was it just a regular
zone valve? I'm looking for something to control rads with (15mm would
be OK). Cheapest 24v (I really want 12v, but 24 is OK, mains is not)
solution seems to be a thermal wax valve, but as the valves will go in
the roof voids, I'm free to use anything.

If you're into a bit of DIY (:-)) Sunvic's mains MOMO valves actually have
24V (IIRC) relays driving the motor. They're driven off the mains by small
bridge rectifier + capacitor circuits which you could remove and rewire so
that all the control side was 24V, with only mains powering the actual
motors. Being MOMO they don't keep consuming power when open, only when
moving from open to closed or v/v.



--
John Stumbles -- http://yaph.co.uk

Who's *really* behind all these conspiracy theories?

On 12 May, 22:55, Tim S wrote:

Do you have a lead for the electric ball valve? Or was it just a regular
zone valve? I'm looking for something to control rads with (15mm would be
OK). Cheapest 24v (I really want 12v, but 24 is OK, mains is not) solution
seems to be a thermal wax valve, but as the valves will go in the roof
voids, I'm free to use anything.

It was a Belimo 1/4 turn ball valve with an actuator on it on the
mains water supply. It wouldn't be suitable for LTHW. A 2-port zone
valve would be cheapest for your application.
If you're shutting off rads you should have a variable speed pump or
a pressure control valve.

Onetap coughed up some electrons that declared:

On 12 May, 22:55, Tim S wrote:

Do you have a lead for the electric ball valve? Or was it just a regular
zone valve? I'm looking for something to control rads with (15mm would be
OK). Cheapest 24v (I really want 12v, but 24 is OK, mains is not)
solution seems to be a thermal wax valve, but as the valves will go in
the roof voids, I'm free to use anything.

It was a Belimo 1/4 turn ball valve with an actuator on it on the
mains water supply.

OK - I found some references.

It wouldn't be suitable for LTHW. A 2-port zone
valve would be cheapest for your application.

Unfortunately, 12 or 24V seem rare as hen's teeth and expensive (12v=marine
use = stupid markup, Honeywell make a 24V version but buggered if I can
find a supplier). Because the room stats are incapable of switching mains,
I don't really want to have a relay box and another cable loop everywhere
(and the extra design hassle of keeping mains and SELV provably separated
at each point). The stats (Heatmiser) are 12V supply, but their tech said
I'd be fine switching 24V, which sounds like a -12/0/+12V supply to me

If you're shutting off rads you should have a variable speed pump or
a pressure control valve.

Indeed. I'll either use a Grundfos Alpha+ or a Wilo Smart (latter is
cheaper).

Cheers

Tim

On Wed, 13 May 2009 09:57:17 +0100, Tim S wrote:

Unfortunately, 12 or 24V seem rare as hen's teeth and expensive

Don't forget the old resistor-glued-to-a-TRV trick. Labour intensive to
make and you have to be able to get into the TRV to get at the temp
sensing element, and of course it operates arse-about-tit: apply power to
shut it off (but about 1 Watt will do IIRC). But cheap as chips,
materials-wise.


--
John Stumbles -- http://yaph.co.uk

YAPH coughed up some electrons that declared:

On Wed, 13 May 2009 09:57:17 +0100, Tim S wrote:

Unfortunately, 12 or 24V seem rare as hen's teeth and expensive

Don't forget the old resistor-glued-to-a-TRV trick. Labour intensive to
make and you have to be able to get into the TRV to get at the temp
sensing element, and of course it operates arse-about-tit: apply power to
shut it off (but about 1 Watt will do IIRC). But cheap as chips,
materials-wise.



That's a good idea. Basically a TWA in reverse. TWA (Thermal Wax) seem to be
the mostly likely component for the job:

It's certainly a fallback - advantages, the thermal head is still available
as a fallback if the fancy bits break (big override switch on pump) and
it's doable directly from 12V, so I'd need about an amp or so spare on the
PSU to handle 8 rooms.

Reckons the Honeywell TRV head looks a possibility - plastic and even slots
to bring cable out of. Definately the cheapest, with that head being 10-15
quid + valve.

I have come across a couple of hard to get 24V TWAs (Emmeti Topway was one
IIRC). Not too expensive, more like 30 quid. Have to go hunting again for
them..

Cheers

Tim

On Wed, 13 May 2009 13:24:20 +0100, Tim S wrote:

Reckons the Honeywell TRV head looks a possibility - plastic and even
slots to bring cable out of. Definately the cheapest, with that head
being 10-15 quid + valve.

Those were the ones I used, for precisely that reason. Prolly even got
some kicking around (I never got the Tuits installed to make the system
work as envisaged :-(). My posting on how I did it is still kicking around
on th'interwub somewhere ...

--
John Stumbles -- http://yaph.co.uk

Just because you're paranoid doesn't mean they're not out to get you.

YAPH coughed up some electrons that declared:

On Wed, 13 May 2009 13:24:20 +0100, Tim S wrote:

Reckons the Honeywell TRV head looks a possibility - plastic and even
slots to bring cable out of. Definately the cheapest, with that head
being 10-15 quid + valve.

Those were the ones I used, for precisely that reason. Prolly even got
some kicking around (I never got the Tuits installed to make the system
work as envisaged :-(). My posting on how I did it is still kicking around
on th'interwub somewhere ...


Did you go for a metal clad resistor or just something normal in the couple
of watt range?

It would probably take less time to make these up than to source a sensibly
priced TWA. And I could dispense with the -12V supply and the extra wire in
the loop.

Need a relay to invert the signal (Heatmisers are SPST call for heat) but
that would be a weedy little thing and all SELV - can go in the junction
box.

I did ring Heatmiser. They couldn't recommend a 12 or 24v valve - they said
use a mains relay or their fancy wiring centre (which is quite nice and
gives you the 12V supply). I said as much, but pointed out I'd have a star
topology which meant a lot of cable going to one corner of the house - my
scheme is a bus topology with local drops of 12V/GND and RS485 and a tiny
junction box to connect the local programmer valve - much less bulk of
cables.

On Wed, 13 May 2009 14:23:04 +0100, Tim S wrote:

Did you go for a metal clad resistor or just something normal in the
couple of watt range?

Little square surface-mount type from Farnell, IIRC. Soldered wires to the
connection pads and epoxied it onto the wax pot. I think I found about 10
ohm did the trick, but if you google this group for my name plus TRV and
resistor you may find the original article - late 90s-ish. (Thought I had
a copy kicking around but can't lay my hands on it ATM.)

--
John Stumbles -- http://yaph.co.uk

Thank God I'm an atheist

On Wed, 13 May 2009 13:34:43 +0000, YAPH wrote:

Little square surface-mount type from Farnell, IIRC. Soldered wires to
the connection pads and epoxied it onto the wax pot. I think I found
about 10 ohm

give or take a zero, durrr....

--
John Stumbles -- http://yaph.co.uk

I can't stand intolerance

In article ,
YAPH writes:
On Wed, 13 May 2009 14:23:04 +0100, Tim S wrote:

Did you go for a metal clad resistor or just something normal in the
couple of watt range?

Little square surface-mount type from Farnell, IIRC. Soldered wires to the
connection pads and epoxied it onto the wax pot. I think I found about 10
ohm did the trick, but if you google this group for my name plus TRV and
resistor you may find the original article - late 90s-ish. (Thought I had
a copy kicking around but can't lay my hands on it ATM.)

Before I installed central heating, I had a number of gas wall
heaters, with proportional control thermostat philes (Drugasar).
I taped about 3 1/4W resistors around the phile, and ran them
from one of those little wall-warts with switch-selectable output
voltage. The switch selection effectively adjusted the setback
temperature, by varying the resistor power. I can't recall the
values I used now (it was ~10 years ago), but they would in any
case be different in different circumstances. You will need to
do some experimentation to so how many degrees setback you get
from each 1W of power.

The original version used plug-in X10 switches to switch the wall
wart on/off, but that was later changed to use programmable alarm
outputs driving a relay, when the alarm/home-automation cabling
went in.

As Tim says, the logic is inverted, which in my case meant that if
there was a power cut, the heaters all came on (not requiring any
mains power themselves), but that didn't happen often enough to
worry about.

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]