more gravity fed shower fitting questions! I need to cut pipes to
branch off to the shower but have very limited space, what's the
professional's approach? the space in which to use a pipe cutter is
about 1cm from other pipework that can't be moved and obviously I'm
loath to pull the pipes about too much.

Also, I'm planning to branch off existing bathroom pipework, the
instructions for a mira realm says cold must come from a cistern, I'm
not sure if the cold is from mains or not, is that likely, or even
something to worry about? It's certainly at higher pressure than the
hot water.

lastly (ahem) anyone got experience with a waterford? I want a decent
unit, but Mira's are too expensive. Thanks.

Spat wrote:
more gravity fed shower fitting questions! I need to cut pipes to
branch off to the shower but have very limited space, what's the
professional's approach? the space in which to use a pipe cutter is
about 1cm from other pipework that can't be moved and obviously I'm
loath to pull the pipes about too much.

Also, I'm planning to branch off existing bathroom pipework, the
instructions for a mira realm says cold must come from a cistern, I'm
not sure if the cold is from mains or not, is that likely, or even
something to worry about? It's certainly at higher pressure than the
hot water.

lastly (ahem) anyone got experience with a waterford? I want a decent
unit, but Mira's are too expensive. Thanks.

I would certainly answer your second question before worrying about
your first - that is, what sort of shower you are going to end up with,
as each have different (and v. specific) requirements regarding the
type of water supply. For instance you certainly could not connect
mains cold water to a pumped shower.

Regarding the pipe cutting dilemma, if you are joining copper to copper
with soldered fittings I would have no hesitation in using a hacksaw or
other primitave cutting device, anything that doesn't distort the
roundness of the pipe basically. (Make sure you wash out swarf first
though before connecting to your new shower).

(Sits back and awaits furious admonishings...)

If you've got plastic pipe or are going to be using push-on fittings, I
would recommend the use of a proper pipe cutter, which will necessitate
(it seems) some rearranging (or further disconnecting downstream
perhaps?) of the pipes. Often if you make one cut further back in a
pipe run, the pipe will flex giving you plenty of room to get a pipe
cutter to it.

On 3 Oct 2006 05:27:48 -0700 someone who may be "Spat"
wrote this:-

more gravity fed shower fitting questions! [snip]

Also, I'm planning to branch off existing bathroom pipework, the
instructions for a mira realm says cold must come from a cistern, I'm
not sure if the cold is from mains or not, is that likely,

It depends on which part of which country the house is in and the
age of the plumbing. Perhaps 50/50 over the whole of the UK.

or even something to worry about?

It is very much something to worry about. Imagine the situation
where someone is showering under a non-thermostatic shower when the
mains water fails for some reason, but the gravity fed hot water
continues for some time. They are likely to be scalded, perhaps
killed.

It's certainly at higher pressure than the hot water.

Then it is highly likely to be from the mains. Follow the
instructions, someone went to the trouble of writing them for a
number of reasons including your safety.

If the shower is thermostatic and you wish to trust your safety to a
mechanical gadget, rather than doing the plumbing properly, then a
pressure equalising valve can be fitted to make the thermostatic
valve work somewhat better.


--
David Hansen, Edinburgh
I will *always* explain revoked encryption keys, unless RIP prevents me
http://www.opsi.gov.uk/acts/acts2000/00023--e.htm#54

Wingedcat wrote:
I would certainly answer your second question before worrying about
your first - that is, what sort of shower you are going to end up with,
as each have different (and v. specific) requirements regarding the
type of water supply. For instance you certainly could not connect
mains cold water to a pumped shower.

thanks. I'm going for thermostatic mixer from G fed water, no pump.

Regarding the pipe cutting dilemma, if you are joining copper to copper
with soldered fittings I would have no hesitation in using a hacksaw or
other primitave cutting device, anything that doesn't distort the
roundness of the pipe basically. (Make sure you wash out swarf first
though before connecting to your new shower).

(Sits back and awaits furious admonishings...)

If you've got plastic pipe or are going to be using push-on fittings, I
would recommend the use of a proper pipe cutter, which will necessitate
(it seems) some rearranging (or further disconnecting downstream
perhaps?) of the pipes. Often if you make one cut further back in a
pipe run, the pipe will flex giving you plenty of room to get a pipe
cutter to it.

Plastic would be more convenient as i need to make a few turns (2X90
degree) , but can it attach directly to the shower unit? Reading
through posts here tho, many people seem to think copper is the "right"
way and it will make cutting easier if i can get away with a hacksaw.
The pipe cutting is to put T pieces in so I guess they'll be copper
anyway. To give enough space to fit the pipes together, the chases in
the wall will have to be pretty deep though which seems an advantage of
plastic's flexibility.

David Hansen wrote:
On 3 Oct 2006 05:27:48 -0700 someone who may be "Spat"
wrote this:-

more gravity fed shower fitting questions! [snip]

Also, I'm planning to branch off existing bathroom pipework, the
instructions for a mira realm says cold must come from a cistern, I'm
not sure if the cold is from mains or not, is that likely,

It depends on which part of which country the house is in and the
age of the plumbing. Perhaps 50/50 over the whole of the UK.

or even something to worry about?

It is very much something to worry about. Imagine the situation
where someone is showering under a non-thermostatic shower when the
mains water fails for some reason, but the gravity fed hot water
continues for some time. They are likely to be scalded, perhaps
killed.

It's certainly at higher pressure than the hot water.

Then it is highly likely to be from the mains. Follow the
instructions, someone went to the trouble of writing them for a
number of reasons including your safety.

If the shower is thermostatic and you wish to trust your safety to a
mechanical gadget, rather than doing the plumbing properly, then a
pressure equalising valve can be fitted to make the thermostatic
valve work somewhat better.


Thanks. I guess the water is at mains pressure then, my question was
prompted because nearly everywhere I've read, instructions for fitting
a thermostatic mixer shower from GFed suggested tapping off from
existing bathroom piepwork was ok, just the Mira instructions stating
different. Looks like I'll have to run a huge line from my loft water
tank, a right pain!

--
David Hansen, Edinburgh
I will *always* explain revoked encryption keys, unless RIP prevents me
http://www.opsi.gov.uk/acts/acts2000/00023--e.htm#54

On 3 Oct 2006 05:27:48 -0700, "Spat" wrote:

|more gravity fed shower fitting questions! I need to cut pipes to
|branch off to the shower but have very limited space, what's the
|professional's approach? the space in which to use a pipe cutter is
|about 1cm from other pipework that can't be moved and obviously I'm
|loath to pull the pipes about too much.

I would use a hacksaw or a fine toothed hacksaw blade and some gaffer tape
round the blade to form a handle, with the cut cleaned up by a fine file. A
miniature hacksaw might also work OK again followed by a fine file.
--
Dave Fawthrop dave hyphenologist co uk Google Groups is IME the *worst*
method of accessing usenet. GG subscribers would be well advised get a
newsreader, say Agent, and a newsserver, say news.individual.net. These
will allow them: to see only *new* posts, a killfile, and other goodies.

Spat wrote:
more gravity fed shower fitting questions! I need to cut pipes to
branch off to the shower but have very limited space, what's the
professional's approach? the space in which to use a pipe cutter is
about 1cm from other pipework that can't be moved and obviously I'm
loath to pull the pipes about too much.

Thats enough to get a small rotating pipe cutter in, and don't be afraid
to bend copper pipes a bit.

Or you can use a dremel and a cutting disk..

I have often replaced quite large sections of pipe just to get around
this problem.

Don't be afraid to cut away madly to allow a job to be done, you can
always put pack stuff later.


Also, I'm planning to branch off existing bathroom pipework, the
instructions for a mira realm says cold must come from a cistern, I'm
not sure if the cold is from mains or not, is that likely, or even
something to worry about? It's certainly at higher pressure than the
hot water.

Oh. I don't like the sound of that...

lastly (ahem) anyone got experience with a waterford? I want a decent
unit, but Mira's are too expensive. Thanks.

My only complaints on chap shower units have been the plastic shower
HEADS. Our mains pressure simply blows them apart..literally. Only metal
heads seem to be able to handle it.

The mixers themselves - well some are a bit plasticky and have wobbly
taps, but they all work OK.

Wingedcat wrote:
Spat wrote:
more gravity fed shower fitting questions! I need to cut pipes to
branch off to the shower but have very limited space, what's the
professional's approach? the space in which to use a pipe cutter is
about 1cm from other pipework that can't be moved and obviously I'm
loath to pull the pipes about too much.

Also, I'm planning to branch off existing bathroom pipework, the
instructions for a mira realm says cold must come from a cistern, I'm
not sure if the cold is from mains or not, is that likely, or even
something to worry about? It's certainly at higher pressure than the
hot water.

lastly (ahem) anyone got experience with a waterford? I want a decent
unit, but Mira's are too expensive. Thanks.

I would certainly answer your second question before worrying about
your first - that is, what sort of shower you are going to end up with,
as each have different (and v. specific) requirements regarding the
type of water supply. For instance you certainly could not connect
mains cold water to a pumped shower.

Regarding the pipe cutting dilemma, if you are joining copper to copper
with soldered fittings I would have no hesitation in using a hacksaw or
other primitave cutting device, anything that doesn't distort the
roundness of the pipe basically. (Make sure you wash out swarf first
though before connecting to your new shower).

(Sits back and awaits furious admonishings...)

Only on the basis of the burrs sawing introduces, and the difficulty of
removing them in a tight area. Its bad enough cleaning up the pipes with
wire wool, in a tight place, let alone BURRS.



If you've got plastic pipe or are going to be using push-on fittings, I
would recommend the use of a proper pipe cutter, which will necessitate
(it seems) some rearranging (or further disconnecting downstream
perhaps?) of the pipes. Often if you make one cut further back in a
pipe run, the pipe will flex giving you plenty of room to get a pipe
cutter to it.

Yup.

"Spat" wrote in message
oups.com...

David Hansen wrote:
On 3 Oct 2006 05:27:48 -0700 someone who may be "Spat"
wrote this:-

more gravity fed shower fitting questions! [snip]

Also, I'm planning to branch off existing bathroom pipework, the
instructions for a mira realm says cold must come from a cistern, I'm
not sure if the cold is from mains or not, is that likely,

It depends on which part of which country the house is in and the
age of the plumbing. Perhaps 50/50 over the whole of the UK.

or even something to worry about?

It is very much something to worry about. Imagine the situation
where someone is showering under a non-thermostatic shower when the
mains water fails for some reason, but the gravity fed hot water
continues for some time. They are likely to be scalded, perhaps
killed.

It's certainly at higher pressure than the hot water.

Then it is highly likely to be from the mains. Follow the
instructions, someone went to the trouble of writing them for a
number of reasons including your safety.

If the shower is thermostatic and you wish to trust your safety to a
mechanical gadget, rather than doing the plumbing properly, then a
pressure equalising valve can be fitted to make the thermostatic
valve work somewhat better.


Thanks. I guess the water is at mains pressure then, my question was
prompted because nearly everywhere I've read, instructions for fitting
a thermostatic mixer shower from GFed suggested tapping off from
existing bathroom piepwork was ok, just the Mira instructions stating
different. Looks like I'll have to run a huge line from my loft water
tank, a right pain!

When you do so it "should* have a separate, slightly lower position than the
outlet for the hot tank. This is so (as suggested elsewhere) if the water
fails and the tank empties, the hot water runs out first so you don't get
scalded. It's standard for pumped showers too.


--
Bob Mannix
(anti-spam is as easy as 1-2-3 - not)

Spat wrote:
Wingedcat wrote:
I would certainly answer your second question before worrying about
your first - that is, what sort of shower you are going to end up with,
as each have different (and v. specific) requirements regarding the
type of water supply. For instance you certainly could not connect
mains cold water to a pumped shower.

thanks. I'm going for thermostatic mixer from G fed water, no pump.

Regarding the pipe cutting dilemma, if you are joining copper to copper
with soldered fittings I would have no hesitation in using a hacksaw or
other primitave cutting device, anything that doesn't distort the
roundness of the pipe basically. (Make sure you wash out swarf first
though before connecting to your new shower).

(Sits back and awaits furious admonishings...)

If you've got plastic pipe or are going to be using push-on fittings, I
would recommend the use of a proper pipe cutter, which will necessitate
(it seems) some rearranging (or further disconnecting downstream
perhaps?) of the pipes. Often if you make one cut further back in a
pipe run, the pipe will flex giving you plenty of room to get a pipe
cutter to it.

Plastic would be more convenient as i need to make a few turns (2X90
degree) , but can it attach directly to the shower unit? Reading
through posts here tho, many people seem to think copper is the "right"
way and it will make cutting easier if i can get away with a hacksaw.
The pipe cutting is to put T pieces in so I guess they'll be copper
anyway. To give enough space to fit the pipes together, the chases in
the wall will have to be pretty deep though which seems an advantage of
plastic's flexibility.


I prefer copper because it adds support to the shower mixer. If you can
solder one joint, you can solder 6-8 allright..and right angle bends are
all in the days work. Then with plastic supplementary bonding raises its
ugly head...and as you have pointed out how to attach it to the shower
unit..

David Hansen wrote:
On 3 Oct 2006 05:27:48 -0700 someone who may be "Spat"
wrote this:-

more gravity fed shower fitting questions! [snip]

Also, I'm planning to branch off existing bathroom pipework, the
instructions for a mira realm says cold must come from a cistern, I'm
not sure if the cold is from mains or not, is that likely,

It depends on which part of which country the house is in and the
age of the plumbing. Perhaps 50/50 over the whole of the UK.

or even something to worry about?

It is very much something to worry about. Imagine the situation
where someone is showering under a non-thermostatic shower when the
mains water fails for some reason, but the gravity fed hot water
continues for some time. They are likely to be scalded, perhaps
killed.

Blimey. You expect to not be able to jump out of a scalding shower AND
not be able to limit your hot water tank to an non lethal temperature.

Or are you merely a Nu Laber supporter who thinks that his intelligence
is infinitely greater than they Public At Large,, who must be cocooned
from their own stupidity as they are incapable of Getting Anything Right
without inspectors and legislation to enforce it?



It's certainly at higher pressure than the hot water.

Then it is highly likely to be from the mains. Follow the
instructions, someone went to the trouble of writing them for a
number of reasons including your safety.

You hafta larf doncha. They don't care about sfatey, just not getting sued.


If the shower is thermostatic and you wish to trust your safety to a
mechanical gadget, rather than doing the plumbing properly, then a
pressure equalising valve can be fitted to make the thermostatic
valve work somewhat better.



Yawn.
All together now

"Ring a ring of Roses
A Pocket full of Posies
Atishoo! Atishoo!
We All Fall Down!"

Spat wrote:
David Hansen wrote:
On 3 Oct 2006 05:27:48 -0700 someone who may be "Spat"
wrote this:-

more gravity fed shower fitting questions! [snip]

Also, I'm planning to branch off existing bathroom pipework, the
instructions for a mira realm says cold must come from a cistern, I'm
not sure if the cold is from mains or not, is that likely,
It depends on which part of which country the house is in and the
age of the plumbing. Perhaps 50/50 over the whole of the UK.

or even something to worry about?
It is very much something to worry about. Imagine the situation
where someone is showering under a non-thermostatic shower when the
mains water fails for some reason, but the gravity fed hot water
continues for some time. They are likely to be scalded, perhaps
killed.

It's certainly at higher pressure than the hot water.
Then it is highly likely to be from the mains. Follow the
instructions, someone went to the trouble of writing them for a
number of reasons including your safety.

If the shower is thermostatic and you wish to trust your safety to a
mechanical gadget, rather than doing the plumbing properly, then a
pressure equalising valve can be fitted to make the thermostatic
valve work somewhat better.


Thanks. I guess the water is at mains pressure then, my question was
prompted because nearly everywhere I've read, instructions for fitting
a thermostatic mixer shower from GFed suggested tapping off from
existing bathroom piepwork was ok, just the Mira instructions stating
different. Looks like I'll have to run a huge line from my loft water
tank, a right pain!

I've run showers off mains cold and tanked hot. They work,. Its illegal
though because any blockage can cause the cold water to backfill the hot
water tank and cistern. I think a non-return valve would fix that. Of
course its vile, because anyone opening taps anywhere alters the
balance, and the shower temp is all over the place. Even thermo showers
have a hard time coping.

In fact you can get curious effects like this on full pressure systems too.

As I discovered when I installed a mixer on ours, before fitting the
shower head. I left the head blanked off, but forgot to switch the
shower off after leak testing..it became a matter of pure luck as to
whether any given hot or cold tap would deliver hot, or cold water..in
fact most did both, at different times..

I prefer copper because it adds support to the shower mixer. If you can
solder one joint, you can solder 6-8 allright..and right angle bends are
all in the days work. Then with plastic supplementary bonding raises its
ugly head...and as you have pointed out how to attach it to the shower
unit..

Supplementary bonding is easier with plastic. It doesn't need any.

However, I still agree that showers are best done in copper, purely because
of mechanical strength.

Christian.

Christian McArdle wrote:
I prefer copper because it adds support to the shower mixer. If you can
solder one joint, you can solder 6-8 allright..and right angle bends are
all in the days work. Then with plastic supplementary bonding raises its
ugly head...and as you have pointed out how to attach it to the shower
unit..

Supplementary bonding is easier with plastic. It doesn't need any.

However, I still agree that showers are best done in copper, purely because
of mechanical strength.

Christian.


Ah. Thats good news then.

On 3 Oct 2006 06:17:34 -0700 someone who may be "Spat"
wrote this:-

my question was
prompted because nearly everywhere I've read, instructions for fitting
a thermostatic mixer shower from GFed suggested tapping off from
existing bathroom piepwork was ok,

It can be done with a thermostatic mixer. However, it is still
better to have a separate cold feed.

Looks like I'll have to run a huge line from my loft water
tank, a right pain!

If the shower is some way away from the tank.


--
David Hansen, Edinburgh
I will *always* explain revoked encryption keys, unless RIP prevents me
http://www.opsi.gov.uk/acts/acts2000/00023--e.htm#54

On Tue, 03 Oct 2006 14:41:15 +0100 someone who may be The Natural
Philosopher wrote this:-

Blimey. You expect to not be able to jump out of a scalding shower

What I can or cannot do is irrelevant. Not everyone can jump out of
scalding water.

AND
not be able to limit your hot water tank to an non lethal temperature.

People have died at modest temperatures. It is not just water at say
120C that is lethal.

Or are you merely a Nu Laber supporter who thinks that his intelligence
is infinitely greater than they Public At Large,, who must be cocooned
from their own stupidity as they are incapable of Getting Anything Right
without inspectors and legislation to enforce it?

Excellent, a personal attack. Always mildly reassuring.


--
David Hansen, Edinburgh
I will *always* explain revoked encryption keys, unless RIP prevents me
http://www.opsi.gov.uk/acts/acts2000/00023--e.htm#54

"David Hansen" wrote in message
...
On Tue, 03 Oct 2006 14:41:15 +0100 someone who may be The Natural
Philosopher wrote this:-

Blimey. You expect to not be able to jump out of a scalding shower

What I can or cannot do is irrelevant. Not everyone can jump out of
scalding water.

AND
not be able to limit your hot water tank to an non lethal temperature.

People have died at modest temperatures. It is not just water at say
120C that is lethal.


I now it's been a long time since I went to school ... and perhaps with the
nu-Labor modular exams, things have changed; -- but IIRC "water at say 120C
" used to be called 'steam'! [at Standard Atmosphere and Pressure for the
pedantic!]


--

Brian

David Hansen wrote:
On Tue, 03 Oct 2006 14:41:15 +0100 someone who may be The Natural
Philosopher wrote this:-

Blimey. You expect to not be able to jump out of a scalding shower

What I can or cannot do is irrelevant. Not everyone can jump out of
scalding water.

AND
not be able to limit your hot water tank to an non lethal temperature.

People have died at modest temperatures. It is not just water at say
120C that is lethal.

Which is why it is pretty much regulation to set your tank stat at no
more than 60C.


Or are you merely a Nu Laber supporter who thinks that his intelligence
is infinitely greater than they Public At Large,, who must be cocooned
from their own stupidity as they are incapable of Getting Anything Right
without inspectors and legislation to enforce it?

Excellent, a personal attack. Always mildly reassuring.


Less an attack, than a random observation.

Its widely known that hot water should be between 45 and 65C..and should
be at the lower end of the scale where elderly and physically disabled
people are likely to use it.

Its widely known that the reasons that its not good to mix high and low
pressure cold and hot water in any kind of tap except one where the
mixing is done externally to the device, is because if the problems of
backfilling header tanks.

You are also far more likely to jump into a bath of scalding hot water
than be able to physically walk into a shower, have it go scalding on
you, and not be able to walk out,.

In short your arguments don't stack up, you are merely parading silly
ideas as if they meant something and are in fact a total tosser.

Ergo, you probably voted Laber.

Brian Sharrock wrote:
"David Hansen" wrote in message
...
On Tue, 03 Oct 2006 14:41:15 +0100 someone who may be The Natural
Philosopher wrote this:-

Blimey. You expect to not be able to jump out of a scalding shower
What I can or cannot do is irrelevant. Not everyone can jump out of
scalding water.

AND
not be able to limit your hot water tank to an non lethal temperature.
People have died at modest temperatures. It is not just water at say
120C that is lethal.


I now it's been a long time since I went to school ... and perhaps with the
nu-Labor modular exams, things have changed; -- but IIRC "water at say 120C
" used to be called 'steam'! [at Standard Atmosphere and Pressure for the
pedantic!]


Oh don't be silly. Like Humpty Dumpty, his words mean what HE wants them
to mean.

On Tue, 03 Oct 2006 21:53:25 GMT someone who may be "Brian Sharrock"
wrote this:-

I now it's been a long time since I went to school ... and perhaps with the
nu-Labor modular exams, things have changed; -- but IIRC "water at say 120C
" used to be called 'steam'! [at Standard Atmosphere and Pressure for the
pedantic!]

The bit in brackets is the important bit. While one is unlikely to
come across water at more then 100C in domestic circumstances that
does not mean it doesn't exist. It is found (in pipes) in some
commercial/industrial settings. If the water escapes from the pipe
then obviously it turns into steam and a little boiling water. This
sort of thing is best thought of as liquid steam and treated with as
much respect.


--
David Hansen, Edinburgh
I will *always* explain revoked encryption keys, unless RIP prevents me
http://www.opsi.gov.uk/acts/acts2000/00023--e.htm#54

On Wed, 04 Oct 2006 01:23:49 +0100 someone who may be The Natural
Philosopher wrote this:-

You are also far more likely to jump into a bath of scalding hot water
than be able to physically walk into a shower, have it go scalding on
you, and not be able to walk out,.

I'll ignore the parts of your posting that are another personal
attack. Readers can make up their minds about how to treat your
postings.

The bit that is worth replying to is quoted above. It assumes that
everyone who uses a bath or shower is sprightly. However, not
everyone is.


--
David Hansen, Edinburgh
I will *always* explain revoked encryption keys, unless RIP prevents me
http://www.opsi.gov.uk/acts/acts2000/00023--e.htm#54

On Tue, 03 Oct 2006 14:46:38 +0100, The Natural Philosopher
wrote:

As I discovered when I installed a mixer on ours, before fitting the
shower head. I left the head blanked off, but forgot to switch the
shower off after leak testing..it became a matter of pure luck as to
whether any given hot or cold tap would deliver hot, or cold water..in
fact most did both, at different times..

Thereby simulating a combi boiler.


--

David Hansen wrote:
On Tue, 03 Oct 2006 14:41:15 +0100 someone who may be The Natural
Philosopher wrote this:-

Blimey. You expect to not be able to jump out of a scalding shower

What I can or cannot do is irrelevant. Not everyone can jump out of
scalding water.

AND
not be able to limit your hot water tank to an non lethal temperature.

People have died at modest temperatures. It is not just water at say
120C that is lethal.

You can't have *water* coming out of a shower at 120C, it becomes
steam at 100C at atmospheric pressure.

--
Chris Green

You can't have *water* coming out of a shower at 120C, it becomes
steam at 100C at atmospheric pressure.

Yes you can. When it is in the pipe, it is pressurised. It takes a finite
time for it to evaporate when it emerges into atmospheric pressure.

Christian.

Christian McArdle wrote:
You can't have *water* coming out of a shower at 120C, it becomes
steam at 100C at atmospheric pressure.

Yes you can. When it is in the pipe, it is pressurised. It takes a finite
time for it to evaporate when it emerges into atmospheric pressure.

Christian.


But the issue here is one of using a hot water TANK on UNPRESSURISED hot
water supply from a CISTERN type header tank.

As usual we have weaseling from those who realise what asses they are
making of themselves.

You can't have *water* coming out of a shower at 120C, it becomes
steam at 100C at atmospheric pressure.

Yes you can. When it is in the pipe, it is pressurised. It takes a finite
time for it to evaporate when it emerges into atmospheric pressure.

But the issue here is one of using a hot water TANK on UNPRESSURISED hot
water supply from a CISTERN type header tank.

Well that's what you're thinking of. I'm thinking of a malfunctioning system
that has boiled and gone overpressure with a malfunctioning vent. After all,
why else would the water be at 120C?

Christian.

"Christian McArdle" wrote in message
.. .
You can't have *water* coming out of a shower at 120C, it becomes
steam at 100C at atmospheric pressure.

Yes you can. When it is in the pipe, it is pressurised. It takes a
finite time for it to evaporate when it emerges into atmospheric
pressure.

But the issue here is one of using a hot water TANK on UNPRESSURISED hot
water supply from a CISTERN type header tank.

Well that's what you're thinking of. I'm thinking of a malfunctioning
system that has boiled and gone overpressure with a malfunctioning vent.
After all, why else would the water be at 120C?


Have you any idea what pressure you need to maintain water at 120C?

The Natural Philosopher wrote:
Christian McArdle wrote:
You can't have *water* coming out of a shower at 120C, it becomes
steam at 100C at atmospheric pressure.

Yes you can. When it is in the pipe, it is pressurised. It takes a finite
time for it to evaporate when it emerges into atmospheric pressure.

Christian.


But the issue here is one of using a hot water TANK on UNPRESSURISED hot
water supply from a CISTERN type header tank.

As usual we have weaseling from those who realise what asses they are
making of themselves.

ok ;-) Never realised what my post would start, anyway, thanks for the
replies. It looks like however unlikely, a sensible way is to cold from
the header tank. Should this be in 22mm pipes like the hot? I'll have
to lay pipes in the loft, above or below insulation?

On Wed, 4 Oct 2006 11:35:47 +0100 Fred wrote :
Have you any idea what pressure you need to maintain water at 120C?

About 28 psi or 2 bar according to

http://www.engineeringtoolbox.com/bo...ter-d_926.html

--
Tony Bryer SDA UK 'Software to build on' http://www.sda.co.uk

On 04 Oct 2006 08:20:36 GMT someone who may be
wrote this:-

You can't have *water* coming out of a shower at 120C, it becomes
steam at 100C at atmospheric pressure.

Look at my original posting and note that I didn't claim any such
thing.

What I did say is that it is not just water at 120C that kills
people. Water at more modest temperatures has killed people.


--
David Hansen, Edinburgh
I will *always* explain revoked encryption keys, unless RIP prevents me
http://www.opsi.gov.uk/acts/acts2000/00023--e.htm#54

Have you any idea what pressure you need to maintain water at 120C?

Yes 2 bar, i.e. 1 bar more than atmospheric pressure, which is approximately
the maximum allowed working pressure for many vented hot water cylinders, so
would be unlikely to cause rupture in itself.

Christian.

On 4 Oct 2006 04:13:05 -0700 someone who may be "Spat"
wrote this:-

It looks like however unlikely, a sensible way is to cold from
the header tank. Should this be in 22mm pipes like the hot?

Yes, especially if the shower has a minimal head. It reduces
pressure losses and so gives a better shower. While gravity showers
with 15mm piping can be made satisfactory it is best to use 22mm.

I'll have to lay pipes in the loft, above or below insulation?

Depends on the way the joists run, pipe length, insulation depth,
insulation type and a few other things. However, generally they are
run above the insulation. Make sure the pipe itself is insulated.


--
David Hansen, Edinburgh
I will *always* explain revoked encryption keys, unless RIP prevents me
http://www.opsi.gov.uk/acts/acts2000/00023--e.htm#54

David Hansen wrote:
On 04 Oct 2006 08:20:36 GMT someone who may be
wrote this:-

You can't have *water* coming out of a shower at 120C, it becomes
steam at 100C at atmospheric pressure.

Look at my original posting and note that I didn't claim any such
thing.

What I did say is that it is not just water at 120C that kills
people. Water at more modest temperatures has killed people.

:-)

You're stretching things a bit there, if I say it's "not just
smorfolideonge" that kills people then there is at least an
implication that there is such a thing as smorfolideonge.

--
Chris Green

The message
from contains these words:

You can't have *water* coming out of a shower at 120C, it becomes
steam at 100C at atmospheric pressure.

You could pressurise the shower stall.

--
Skipweasel
Pay no attention to that man behind the curtain.

Christian McArdle wrote:
You can't have *water* coming out of a shower at 120C, it becomes
steam at 100C at atmospheric pressure.
Yes you can. When it is in the pipe, it is pressurised. It takes a finite
time for it to evaporate when it emerges into atmospheric pressure.
But the issue here is one of using a hot water TANK on UNPRESSURISED hot
water supply from a CISTERN type header tank.

Well that's what you're thinking of. I'm thinking of a malfunctioning system
that has boiled and gone overpressure with a malfunctioning vent. After all,
why else would the water be at 120C?


I don't see how a pipe connected to a cylinder connected to a header
tank which is open at the top CAN go 'overpressure'

Christian.

Spat wrote:
The Natural Philosopher wrote:
Christian McArdle wrote:
You can't have *water* coming out of a shower at 120C, it becomes
steam at 100C at atmospheric pressure.
Yes you can. When it is in the pipe, it is pressurised. It takes a finite
time for it to evaporate when it emerges into atmospheric pressure.

Christian.


But the issue here is one of using a hot water TANK on UNPRESSURISED hot
water supply from a CISTERN type header tank.

As usual we have weaseling from those who realise what asses they are
making of themselves.

ok ;-) Never realised what my post would start, anyway, thanks for the
replies. It looks like however unlikely, a sensible way is to cold from
the header tank. Should this be in 22mm pipes like the hot? I'll have
to lay pipes in the loft, above or below insulation?

Yup 22mm.

Below insulation probably simply to avoid possible freezing.

David Hansen wrote:
On 04 Oct 2006 08:20:36 GMT someone who may be
wrote this:-

You can't have *water* coming out of a shower at 120C, it becomes
steam at 100C at atmospheric pressure.

Look at my original posting and note that I didn't claim any such
thing.

What I did say is that it is not just water at 120C that kills
people. Water at more modest temperatures has killed people.


I would thing that the 2 bar pressure necessary to get the water to 120C
and in contact with someones skin without turning to vapour would be
pretty debilitating if maintained for any length of time.

Guy King wrote:
The message
from contains these words:

You can't have *water* coming out of a shower at 120C, it becomes
steam at 100C at atmospheric pressure.

You could pressurise the shower stall.


You could live in a yellow submarine too.

On 04 Oct 2006 13:23:23 GMT someone who may be
wrote this:-

You're stretching things a bit there,

I'm not stretching things at all.


--
David Hansen, Edinburgh
I will *always* explain revoked encryption keys, unless RIP prevents me
http://www.opsi.gov.uk/acts/acts2000/00023--e.htm#54

David Hansen wrote:
On 04 Oct 2006 13:23:23 GMT someone who may be
wrote this:-

You're stretching things a bit there,

I'm not stretching things at all.

I think you're snipping a bit much, the above isn't enough context
to see what it was about:-

Look at my original posting and note that I didn't claim any such
thing.

What I did say is that it is not just water at 120C that kills
people. Water at more modest temperatures has killed people.

:-)

You're stretching things a bit there, if I say it's "not just
smorfolideonge" that kills people then there is at least an
implication that there is such a thing as smorfolideonge.


You even went to the extent of cutting one of my lines in half to try
and make your point.

It's all a bit silly anyway, hardly a serious risks discussion any
more IMHO.

--
Chris Green