Mains Water Pressure. What is "typical"?
Vortex5
bar. About 145 PSI. About 100 metres "head"
Quite honestly I was surprised because instinctively I would have expected
it to be somewhat lower. What is normal though? Is 10 bar unusual?
It's never especially bothered me because I have an IMI pressure regulator
taking the in-house pressure down to about 3 bar....however the regulator
started playing up recently causing the in house static pressure to increase
a lot which could be quite alarming when filling a kettle.
The regulator is now fixed....and I am just curious.
Ron Lowe
That's high.
Normal is around 3-4 bar, but I've seen as high as 7. I've never seen 10.
--
Ron
Bob Minchin
Bob
Tim W
wibbled on Sunday 06 December 2009 19:46
Yes. 4+/- bar is quite common. Mine is 7.5bar, limited to 5 bar by
regulator. 7.5 bar is pretty crazy - couldn't imagine what 10 would be like.
Without a regulator, that would be right at the limit for a lot of
equipment.
--
Tim Watts
This space intentionally left blank...
Steve Walker
> Today I measured my incoming mains water pressure to be a little over 10
> bar. About 145 PSI. About 100 metres "head"
>
> Quite honestly I was surprised because instinctively I would have
> expected it to be somewhat lower. What is normal though? Is 10 bar
> unusual?
Good grief, that's at the limit of my air compressor. Your plumbing must
be made of extra-thick steel pipe.... :o)
Vortex5
"Tim W" <t...@dionic.net> wrote in message
news:hfh2ds$rhm$1...@news.eternal-september.org...
Some years ago I recall measuring the pressure at about 8 bar, but have lost
the pressure gauge.
This measurement was taken with a brand new "monument tools" gauge I
purchased recently.
I originally installed the regulator after fitting a segment of Hep2O
internally and was uncomfortable about such high pressures with plastic
(incidentally Hep2O is rated to at least 12 Bar safe pressure at room temp
so I was being paranoid).
I'm going to borrow another pressure gauge just to be sure I don't have
dodgy equipment! Will also call the waterco to see what they have to say.
Phil L
They'll tell you to turn the pressure down by partially closing the stoptap,
which is what you should have done before buying a regulator.
--
Phil L
RSRL Tipster Of The Year 2008
ephrai...@hotmail.com
I got a bit concerned about some work I was doing, 'phoned our water
provider and asked. We'll check they said.
I awaited their call.
Meanwhile I asked No 1 son, Civil Engineer in water elsewhere in UK
answered,
"Don't be daft, most are about 3bar + or -. "
Then our Co called back... The Chief Engineer of the water Co.
where I live called back. He replied it's about 3.5-4 when it leaves
our header where you live, so based on your postcode, 3 bar would be a
good number!
Ho Hum
EP
Vortex5
>> have dodgy equipment! Will also call the waterco to see what they
>> have to say.
>
> They'll tell you to turn the pressure down by partially closing the
> stoptap, which is what you should have done before buying a regulator.
>
> --
> Phil L
> RSRL Tipster Of The Year 2008
>
Why on earth would they say that? It won't make any difference to the
static pressure.
....or is there a pressure regulator at the exterior stop tap tap? (I find
that hard to believe)
Harry Bloomfield
> They'll tell you to turn the pressure down by partially closing the stoptap,
> which is what you should have done before buying a regulator.
Partially closing the stop tap, will not affect the pressure, except
when there is flow. The static pressure will remain the same as before.
--
Regards,
Harry (M1BYT) (L)
http://www.ukradioamateur.co.uk
Phil L
>
> Why on earth would they say that? It won't make any difference to the
> static pressure.
So even when the tap's just trickling, the water's at 10 bar?
what if it's turned down so low that it's just a slow drip when fully open,
is it still at 10 bar then?
>
> ....or is there a pressure regulator at the exterior stop tap tap? (I
> find that hard to believe)
--
ephrai...@hotmail.com
Turning the supply valve or tap down isn't really a solution if the
pressure is as high as you suggest.
Clamping down a valve may reduce the flow but it won't change the
pressure. When the flow stabilises, the pressure will be the same.
It's a bit like volts and amps. "Volts is pressure, Amps is flow"
Please no flames...... the OT has a pressure (volts) problem not a
flow (amps) problem so squeezing the flow won't help.
I remain curious about the pressure/head being reported in the
original post. I suspect that most providers in UK don't supply water
much above 3, 4 or 5 bar.
EP
Vortex5
"Phil L" <neverc...@hotmail.co.uk> wrote in message
news:T0WSm.12693$Ym4....@text.news.virginmedia.com...
> Vortex5 wrote:
>>
>> Why on earth would they say that? It won't make any difference to the
>> static pressure.
>
>
> So even when the tap's just trickling, the water's at 10 bar?
>
> what if it's turned down so low that it's just a slow drip when fully
> open, is it still at 10 bar then?
>
When the internal tap is off, yes.
Phil L
Yes but it wouldn't stay at that pressure for more than a second or two when
using a tap, so filling a kettle, as you mentioned in your OP, wouldn't be
'alarming'
Vortex5
<ephrai...@hotmail.com> wrote in message
news:abecb3e3-b28e-4de0...@o23g2000vbi.googlegroups.com...
What really confuses me is that there are plenty of houses around me on
higher land, none are more than about 20 metres ( - 2 bars) higher.
I could understand if pressure was (say) 5 bar, but cannot understand why I
see 10. hence the original post.
As I said previously first stop is to double-check the instrument. I'm
wondering if I can bodge up a connection to do this pneumatically at the
local garage.
js.b1
<ephraim_p...@hotmail.com> wrote:
> Please no flames...... the OT has a pressure (volts) problem not a
> flow (amps) problem so squeezing the flow won't help.
Correct.
> I remain curious about the pressure/head being reported in the
> original post. I suspect that most providers in UK don't supply
> water much above 3, 4 or 5 bar.
That's the typical range.
Water co's do play about with pressure, if works are undertaken they
drop it down noticeably, then ramp it back up once complete. The
problem with 10 bar is water hammer (flexible w/machine hoses) is
going to get brutal on the pipework.
Tim W
wibbled on Sunday 06 December 2009 21:53
> They'll tell you to turn the pressure down by partially closing the
> stoptap, which is what you should have done before buying a regulator.
>
Pardon?
Tim W
wibbled on Sunday 06 December 2009 22:27
I beg to differ...
That's not a reliable method of regulating dynamic pressure, which will now
be all over the place depending on demand.
It also doesn't help any equipment that doesn't like such high pressures as
they will be seeing the static pressure regularly. It would also be a
potential disaster if the OP had mains pressure DHW and plastic.
Looking at an offcut of JG Speedfit pipe, I see the pressure ratings are:
12bar at 20C
4 bar at 82C
3 bar at 92C
The figure for 60C isn't given but I can't see JG pipe enjoying 10bar at
much over 40C if that.
IME, certain garden hoses (hello Screwfix) fail early at 7.5bar, so for
anyone with 10bar static pressure, I would rate it as a *very good* idea to
include a pressure regulator next to the stopcock. I found 7.5 bar a big
enough pain to include a regulator in my system. No real disadvantages and a
decent device does not reduce the flow (I tested this specifically). CAme in
very handy when I wanted to install a water heater that required <6bar (the
included pressure relief valve is set to 6bar).
Cheers
Tim
Harry Bloomfield
> Vortex5 wrote:
>>
>> Why on earth would they say that? It won't make any difference to the
>> static pressure.
>
>
> So even when the tap's just trickling, the water's at 10 bar?
>
> what if it's turned down so low that it's just a slow drip when fully open,
> is it still at 10 bar then?
Note the mention of the words 'static pressure' by Vortex5. The word
static means in this case, no water flowing.
Harry Bloomfield
> Clamping down a valve may reduce the flow but it won't change the
> pressure. When the flow stabilises, the pressure will be the same.
> It's a bit like volts and amps. "Volts is pressure, Amps is flow"
>
> Please no flames...... the OT has a pressure (volts) problem not a
> flow (amps) problem so squeezing the flow won't help.
The word you are looking for is 'resistance' in the electrical sense.
A restriction to the flow of water could also be called resistance to
flow.
Phil L
> Phil L <neverc...@hotmail.co.uk>
> wibbled on Sunday 06 December 2009 21:53
>
>
>> They'll tell you to turn the pressure down by partially closing the
>> stoptap, which is what you should have done before buying a
>> regulator.
>>
>
> Pardon?
They'll tell you to turn the pressure down by partially closing the stoptap,
which is what you should have done before buying a regulator.
HTH
Tim W
wibbled on Sunday 06 December 2009 22:55
> Tim W wrote:
>> Phil L <neverc...@hotmail.co.uk>
>> wibbled on Sunday 06 December 2009 21:53
>>
>>
>>> They'll tell you to turn the pressure down by partially closing the
>>> stoptap, which is what you should have done before buying a
>>> regulator.
>>>
>>
>> Pardon?
>
> They'll tell you to turn the pressure down by partially closing the
> stoptap, which is what you should have done before buying a regulator.
I don;t think they will - see my other reply...
Mark
so you went to the same school of plumbing as TMH?
Doctor Drivel
> They'll tell you to turn the pressure down by partially closing the
> stoptap, which is what you should have done before buying a regulator.
The static presure will burst equiment not rated to 10 bar. You NEED a PRV.
Tim W
wibbled on Monday 07 December 2009 00:29
Sometimes the man speaks sense - and this is one such occasion :)
Doctor Drivel
You are an idiot!
geoff
<kill...@invalid.invalid> writes
One for the archives there ...
--
geoff
Tim W
wibbled on Monday 07 December 2009 00:42
Not a plantpot then?
Vortex5
>
> IME, certain garden hoses (hello Screwfix) fail early at 7.5bar, so for
> anyone with 10bar static pressure, I would rate it as a *very good* idea
> to
> include a pressure regulator next to the stopcock. I found 7.5 bar a big
> enough pain to include a regulator in my system. No real disadvantages and
> a
> decent device does not reduce the flow (I tested this specifically). CAme
> in
> very handy when I wanted to install a water heater that required <6bar
> (the
> included pressure relief valve is set to 6bar).
>
> Cheers
>
> Tim
>
> --
> Tim Watts
>
> This space intentionally left blank...
>
That's a good point on hoses.
The "spur" to my outside taps is upstream of the pressure regulator.
It's a real hassle replacing hose connectors all the time (because they get
blown off). ....and have had one "burst".
PeterC
> It also doesn't help any equipment that doesn't like such high pressures as
> they will be seeing the static pressure regularly. It would also be a
> potential disaster if the OP had mains pressure DHW and plastic.
>
> Looking at an offcut of JG Speedfit pipe, I see the pressure ratings are:
>
> 12bar at 20C
> 4 bar at 82C
> 3 bar at 92C
>
> The figure for 60C isn't given but I can't see JG pipe enjoying 10bar at
> much over 40C if that.
Much the same for washing machine hoses, but lower pressures. In the rare
case of a machine that uses hot fill from a combi, the hose will be full of
hot water when the filling ceases and mains pressure on a hot hose...!
A few years ago I installed a Miele and that hose was much higher rated
than standard ones.
--
Peter.
The head of a pin will hold more angels if
it's been flattened with an angel-grinder.
ARWadsworth
It depends what page his Ladybird Book Of Insults is randomly opened to.
Adam
Tim W
wibbled on Monday 07 December 2009 10:04
>
> "Tim W" <t...@dionic.net> wrote in message
>> Not a plantpot then?
>>
>> --
>> Tim Watts
>>
>
> It depends what page his Ladybird Book Of Insults is randomly opened to.
>
> Adam
Ah, the book with 3 pages:
Plantpot
Idiot
And something about blokes in dresses...
dennis@home
"Vortex5" <vortexvisio...@hotmail.com> wrote in message
news:7o3lsqF...@mid.individual.net...
> The "spur" to my outside taps is upstream of the pressure regulator.
>
> It's a real hassle replacing hose connectors all the time (because they
> get blown off). ....and have had one "burst".
Mine blew a watering computer to bits.
Luckily I got a new one from the shop for free.
I had to fit a pressure regulator to stop the new one breaking.
Of course turning the stop tap down as suggested earlier would have resulted
in another blown up watering computer.
Jules
>>> You are an idiot!
>>
>> Not a plantpot then?
>>
>> --
>> Tim Watts
>
> It depends what page his Ladybird Book Of Insults is randomly opened to.
And which pages haven't been chewed (or otherwise soiled).
Vortex4
"dennis@home" <den...@killspam.kicks-ass.net> wrote in message
news:hfil75$o1u$1...@news.datemas.de...
An investigation is in progress.
Dave
Where does that rank against being called a plant pot then?
Dave
Doctor Drivel
As well.
Doctor Drivel
"geoff" <ra...@kateda.org> wrote in message
news:TFmnHodb...@demon.co.uk...
> In message <hfhj2b$32b$1...@news.eternal-september.org>, Doctor Drivel
> <kill...@invalid.invalid> writes
>>
>>"Tim W" <t...@dionic.net> wrote in message
>>You are an idiot!
>
> One for the archives there ...
Fantastic to hear from you Maxie! How is the Paddy band going? You do play
to many drunken audiences? People like you make this world go round and are
a breath of fresh air. You really are. I hope you have stopped swearing at
people in the street and have a handle on the flatulence. Fantastic Maxie.
Truly fantastic.
Tim W
wibbled on Monday 07 December 2009 16:46
Well, I feel aggrieved. Not special enough to get a proper name.
Have you noticed Drivel's creativity is down the pan of late. Must be the
new pills...
Doctor Drivel
> ARWadsworth <adamwa...@blueyonder.co.uk>
> wibbled on Monday 07 December 2009 10:04
>
>>
>> "Tim W" <t...@dionic.net> wrote in message
>
>>> Not a plantpot then?
>>>
>>> --
>>> Tim Watts
>>>
>>
>> It depends what page his Ladybird Book Of Insults is randomly opened to.
>>
>> Adam
>
> Ah, the book with 3 pages:
>
> Plantpot
> Idiot
> And something about blokes in dresses...
You fill all three.
Doctor Drivel
"ARWadsworth" <adamwa...@blueyonder.co.uk> wrote in message
news:Yq4Tm.12793$Ym4....@text.news.virginmedia.com...
> It depends what page his Ladybird Book Of Insults is randomly opened to.
You need tagging.
Doctor Drivel
"PeterC" <giraffe...@homecall.co.uk> wrote in message
news:ihqc28tzjyxm.26rqqy3cjfoq$.dlg@40tude.net...
> On Sun, 06 Dec 2009 22:45:08 +0000, Tim W wrote:
>
>> It also doesn't help any equipment that doesn't like such high pressures
>> as
>> they will be seeing the static pressure regularly. It would also be a
>> potential disaster if the OP had mains pressure DHW and plastic.
>>
>> Looking at an offcut of JG Speedfit pipe, I see the pressure ratings are:
>>
>> 12bar at 20C
>> 4 bar at 82C
>> 3 bar at 92C
>>
>> The figure for 60C isn't given but I can't see JG pipe enjoying 10bar at
>> much over 40C if that.
>
> Much the same for washing machine hoses, but lower pressures. In the rare
> case of a machine that uses hot fill from a combi,
Rare??????
>the hose will be full of
> hot water when the filling ceases and mains pressure on a hot hose...!
>
> A few years ago I installed a Miele and that hose was much higher rated
> than standard ones.
With these sorts of pressures, it is best to have cold fill only. Most
washing machines are these days. Cold 30C washing liquid is very good. The
have a 1/4 turn tap under the sink at the front so the machine is turned off
after each wash, or have a remote operated water tap, available from S/fix
and the likes. Just hit he switch and the cold is off.
Doctor Drivel
"Jules" <jules.rich...@remove.this.gmail.com> wrote in message
news:pan.2009.12.07...@remove.this.gmail.com...
Another pervo that needs tagging.
Grimly Curmudgeon
drugs began to take hold. I remember Ron Lowe <d...@null.com> saying
something like:
>
>That's high.
>
>Normal is around 3-4 bar, but I've seen as high as 7. I've never seen 10.
It's 10bar around here, but the main ressy is on a hillside a fair ways
up, probably 300' or more. Then there's the pumps...
Of course, the Council could put pressure regulators on the system, but
they'd rather keep their employees busy by having to repair the mains
blow-outs every few weeks. Utterly daft.
Grimly Curmudgeon
<neverc...@hotmail.co.uk> saying something like:
>They'll tell you to turn the pressure down by partially closing the stoptap,
>which is what you should have done before buying a regulator.
Utter bollocks.
Tim W
wibbled on Monday 07 December 2009 17:20
If you've been fantacising about big blokes with hairy beards, in dresses,
you really do need help.
Or a Norwegian fisherman.
Jules
>>> It depends what page his Ladybird Book Of Insults is randomly opened to.
>>
>> And which pages haven't been chewed (or otherwise soiled).
>
> Another pervo that needs tagging.
*cheers*
ARWadsworth
Must have 4 pages in the book :-)
Adam
ARWadsworth
"Doctor Drivel" <kill...@invalid.invalid> wrote in message
news:hfjdiq$7he$2...@news.eternal-september.org...
What with?
Adam
geoff
<t...@dionic.net> writes
>ARWadsworth <adamwa...@blueyonder.co.uk>
> wibbled on Monday 07 December 2009 10:04
>
>>
>> "Tim W" <t...@dionic.net> wrote in message
>
>>> Not a plantpot then?
>>>
>>> --
>>> Tim Watts
>>>
>>
>> It depends what page his Ladybird Book Of Insults is randomly opened to.
>>
>> Adam
>
>Ah, the book with 3 pages:
>
>Plantpot
>Idiot
>And something about blokes in dresses...
>
http://www.kateda.org/Kateda.org/Home.html
--
geoff
Dave
Adam, FFS I am trying to have a night cap here and my key board does not
like the spray. It copes, but it takes a week out of the shower to dry out.
Dave
Dave
Horse tranquillisers?
Dave
Jules
> Must have 4 pages in the book :-)
Ha! Doubtless a big potted Aspidistra on the front cover, too...
Doctor Drivel
Fantastic Maxie. You are half naked resplendent in a flock! What a man!!!
Doctor Drivel
Help? So you help people get these blokes.
This one needs tagging.
Tim W
wibbled on Tuesday 08 December 2009 01:04
>
> "geoff" <ra...@kateda.org> wrote in message
>> Yes, the pratt can't tell the difference between a dress and a sarong
>>
>> http://www.kateda.org/Kateda.org/Home.html
>
> Fantastic Maxie. You are half naked resplendent in a flock! What a
> man!!!
Now run along and get some kleenex and tell nursie you need new sheets...
Doctor Drivel
> Doctor Drivel <kill...@invalid.invalid>
> wibbled on Tuesday 08 December 2009 01:04
>
>>
>> "geoff" <ra...@kateda.org> wrote in message
>
>>> Yes, the pratt can't tell the difference between a dress and a sarong
>>>
>>> http://www.kateda.org/Kateda.org/Home.html
>>
>> man!!!
>
> Now run along and get some kleenex and tell nursie you need new sheets...
You are right, Maxie may need these things. What a man! And he plays in a
Paddy band dressed like that as well.
ARWadsworth
"Doctor Drivel" <kill...@invalid.invalid> wrote in message
He made a song for you
<http://www.youtube.com/watch?v=j72-_iF8F4Y&feature=PlayList&p=BC74A1405DCDB78D&index=40>
Adam
matthelliwell
> Today I measured my incoming mains water pressure to be a little over 10
> bar. About 145 PSI. About 100 metres "head"
>
> Quite honestly I was surprised because instinctively I would have expected
> it to be somewhat lower. What is normal though? Is 10 bar unusual?
>
> It's never especially bothered me because I have an IMI pressure regulator
> taking the in-house pressure down to about 3 bar....however the regulator
> started playing up recently causing the in house static pressure to increase
> a lot which could be quite alarming when filling a kettle.
>
> The regulator is now fixed....and I am just curious.
Well the taps I just bought are rated up to 6 bar so I'd certainly
have trouble. You include a turbine on the incoming mains to generates
a bit of electricity everytime you use the taps.
Matt
Roger Dewhurst
> Today I measured my incoming mains water pressure to be a little over 10
> bar. About 145 PSI. About 100 metres "head"
Very high. High enough to burst a defective hot water cylinder and LD
polyethylene pipe. Is the reservoir on a hill nearby or does the
council keep the pressure high by pumping? 5 or 6 bar is much more
reasonable.
>
> Quite honestly I was surprised because instinctively I would have
> expected it to be somewhat lower. What is normal though? Is 10 bar
> unusual?
>
> It's never especially bothered me because I have an IMI pressure
> regulator taking the in-house pressure down to about 3 bar....however
> the regulator started playing up recently causing the in house static
> pressure to increase a lot which could be quite alarming when filling a
> kettle.
Is that what we call an Ajax valve?
R
Roger Dewhurst
>
> <ephrai...@hotmail.com> wrote in message
> news:abecb3e3-b28e-4de0...@o23g2000vbi.googlegroups.com...
>> Just another thought:
>> Turning the supply valve or tap down isn't really a solution if the
>> pressure is as high as you suggest.
>> Clamping down a valve may reduce the flow but it won't change the
>> pressure. When the flow stabilises, the pressure will be the same.
>> It's a bit like volts and amps. "Volts is pressure, Amps is flow"
>>
>> Please no flames...... the OT has a pressure (volts) problem not a
>> flow (amps) problem so squeezing the flow won't help.
>>
>> I remain curious about the pressure/head being reported in the
>> original post. I suspect that most providers in UK don't supply water
>> much above 3, 4 or 5 bar.
>>
>> EP
>
> What really confuses me is that there are plenty of houses around me on
> higher land, none are more than about 20 metres ( - 2 bars) higher.
>
> I could understand if pressure was (say) 5 bar, but cannot understand
> why I see 10. hence the original post.
>
> As I said previously first stop is to double-check the instrument. I'm
> wondering if I can bodge up a connection to do this pneumatically at the
> local garage.
Get some hose. Fit a tyre valve at one end and connect the other to the
tap. Make sure that the hose is vertical and full of air. Turn on the
tap and measure the pressure with tyre pressure gauge.
R
Roger Dewhurst
> On Dec 6, 10:17 pm, "ephraim_p...@hotmail.com"
> <ephraim_p...@hotmail.com> wrote:
>> Please no flames...... the OT has a pressure (volts) problem not a
>> flow (amps) problem so squeezing the flow won't help.
>
>
>> I remain curious about the pressure/head being reported in the
>> original post. I suspect that most providers in UK don't supply
>> water much above 3, 4 or 5 bar.
>
>
> Water co's do play about with pressure, if works are undertaken they
> drop it down noticeably, then ramp it back up once complete. The
> problem with 10 bar is water hammer (flexible w/machine hoses) is
> going to get brutal on the pipework.
Water hammer occurs when flow is shut down suddenly. The water is not
compressible and has inertia. I believe that uPVC pipe has a safety
factor of at least 2 to protect against water hammer.
R
Doctor Drivel
>> You are right, Maxie may need these things. What a man! And he plays
>> in a Paddy band dressed like that as well.
>
> He made a song for you
>
> <http://www.youtube.com/watch?v=j72-_iF8F4Y&feature=PlayList&p=BC74A1405DCDB78D&index=40>
Fantastic. I bet Maxie sings that song on the beach in the Far East up the
tree in that frock. What a man! Truly fantastic. Such a foot tapping tune
as well. Only Maxie can do that.
Geo
>Get some hose.
ok - how long (high) is required for the vertical air-filled bit?
>Fit a tyre valve at one end
Not sure how to do this?
--
Geo
Frank Erskine
wrote:
Ingenuity...
This _is_ a diy group :-)
--
Frank Erskine
Geo
wrote:
>On Wed, 09 Dec 2009 15:55:33 GMT, Geo <hw9j...@dea.spamcon.org>
>wrote:
>
>>On Wed, 09 Dec 2009 10:23:30 +1300, Roger Dewhurst <dewh...@wave.co.nz> wrote:
>>
>>
>>>Get some hose.
>>ok - how long (high) is required for the vertical air-filled bit?
>>
>>>Fit a tyre valve at one end
>>Not sure how to do this?
>
>Ingenuity...
>
>
>This _is_ a diy group :-)
Yebbut - I wasn't sure if the duct tape would hold...
--
Geo
becks...@gmail.com
Tim+
Tim
--
Trolls and troll feeders go in my killfile
Robin
> <becks...@gmail.com> wrote:
>> 10 bar mains pressure is pretty standard now.
>
> Bravo on waiting 7 years to spout bollocks.
>
> Tim
>
supply anything like 10 bar - and a good job too given there are still
very many iron/lead communication/supply pipes.
And nice pun. Pity we can't apply 10 bar to his bollocks/her tits.
--
Robin
reply-to address is (intended to be) valid
stevi...@googlemail.com
> > news:hfh2ds$rhm$1...@news.eternal-september.org...
> >> Ron Lowe <d...@null.com>
> >> wibbled on Sunday 06 December 2009 19:46
> >>> Vortex5 wrote:
> >>>> Today I measured my incoming mains water pressure to be a little
> >>>> over 10 bar. About 145 PSI. About 100 metres "head"
> >>>>
> >>>> expected it to be somewhat lower. What is normal though? Is 10
> >>>> bar unusual?
> >>>>
> >>>> It's never especially bothered me because I have an IMI pressure
> >>>> regulator taking the in-house pressure down to about 3
> >>>> bar....however the regulator started playing up recently causing
> >>>> the in house static pressure to increase a lot which could be
> >>>> quite alarming when filling a kettle.
> >>>>
> >>>
> >>>
> >>> Normal is around 3-4 bar, but I've seen as high as 7. I've never
> >>> seen 10.
> >>>
> >>
> >> Yes. 4+/- bar is quite common. Mine is 7.5bar, limited to 5 bar by
> >> regulator. 7.5 bar is pretty crazy - couldn't imagine what 10 would
> >> be like.
> >>
> >> Without a regulator, that would be right at the limit for a lot of
> >> equipment.
> >> --
> >> Tim Watts
> >>
> >> This space intentionally left blank...
> >>
> >
> > have lost the pressure gauge.
> >
> > This measurement was taken with a brand new "monument tools" gauge I
> > purchased recently.
> >
> > I originally installed the regulator after fitting a segment of Hep2O
> > internally and was uncomfortable about such high pressures with
> > plastic (incidentally Hep2O is rated to at least 12 Bar safe pressure
> > at room temp so I was being paranoid).
> >
> > I'm going to borrow another pressure gauge just to be sure I don't
> > have dodgy equipment! Will also call the waterco to see what they
> > have to say.
> They'll tell you to turn the pressure down by partially closing the stoptap,
> which is what you should have done before buying a regulator.
>
> Phil L
> RSRL Tipster Of The Year 2008
This is a common misconception, partially closing a stopcock down has no bearing on the water pressure, all it does is slow the flow rate down, to reduce pressure you need a pressure reducing valve set at the desired pressure on the draw of side.
The Other John
> On Sunday, December 6, 2009 at 9:53:08 PM UTC, Phil L wrote:
--
TOJ.
Brian Gaff
of people do not understand the difference between flow rate and pressure.
You can often see an initial high pressure spurt if you just close down
the tap a bit but from what I've been told pressure reducers do not have
this pressure build up issue. However thus far despite our pressure being
quite high, nothing has been damaged, though you can clearly hear the
initial spurt when the washing machine solenoid valve initially opens.
Brian
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<stevi...@googlemail.com> wrote in message
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gar...@gmail.com
Construction methods here involve a cast concrete slab with the water pipes set in the concrete. To me, this is BLOODY LUNACY as anyone knows concrete flexes and cracks. Slab leaks are not at all uncommon. Guess why?
newshound
> Here in Palm Desert California our home was built with TWO water pressure regulators. One for the house supply (set at 50psi) and one for the garden sprinkler supply. I have never bothered to determine the latter pressure. Static pressure from the street is 95psi which varies but not by much.
> Construction methods here involve a cast concrete slab with the water pipes set in the concrete. To me, this is BLOODY LUNACY as anyone knows concrete flexes and cracks. Slab leaks are not at all uncommon. Guess why?
>
Brian Gaff
in the world when it affects their bottom line profit.
Brian
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<gar...@gmail.com> wrote in message
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paul....@btinternet.com
Tim+
year old post. I think the problem may well have been resolved by now.
Tim
--
Please don't feed the trolls
whi...@gmail.com
> Today I measured my incoming mains water pressure to be a little over 10
> bar. About 145 PSI. About 100 metres "head"
>
> Quite honestly I was surprised because instinctively I would have expected
> it to be somewhat lower. What is normal though? Is 10 bar unusual?
>
> It's never especially bothered me because I have an IMI pressure regulator
> taking the in-house pressure down to about 3 bar....however the regulator
> started playing up recently causing the in house static pressure to increase
> a lot which could be quite alarming when filling a kettle.
>
> The regulator is now fixed....and I am just curious.
TOJ
> On Sunday, 6 December 2009 19:44:27 UTC, Vortex5 wrote
--
TOJ.
Brian Gaff
since the post replied to here?
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Andrew Gabriel
> The water companies have a statutory minimum pressure they have to deliver. They should also have a statutory maximum of 4 bars. 4.5 is the rated working limit for many central heating boilers etc. Above that will damage them. A fitting blew off the mains supply in my mothers flat at somewhere between 7 and 11 bars. Three flats uninhabitable for 18 months and £200k insurance bill. No liability to the water company. Partially closing the main supply valve reduces flow, (and make noise) but does nothing to reduce pressure. You need a reducer on the system if it is above 4 bars. The big step down valves on the water mains they install now are not fail safe and have a habit of failing by giving full pressure - 11 bars etc. Not good for your system. The design rating of copper pipe is 12 bars but the fittings etc are your weak point. If your system is going to see over 4 bars it needs to be properly pressure tested and certified to take max pressure + 20%. This countries standards are so bad it makes me weep, (my pipework as well).
>
A pressure regulator only really works with a flow through it. The
static pressure (when no flow) will always be higher than the set point
(although not necessarily the fill input pressure - that depends on the
volume of pipework downstream). The downstream plumbing must be able to
handle the static pressure, not just the regulators set point pressure.
--
Andrew
The Natural Philosopher
> On 04/04/2019 18:41, whi...@gmail.com wrote:
>
>> The water companies have a statutory minimum pressure they have to
>> deliver. They should also have a statutory maximum of 4 bars. 4.5 is
>> the rated working limit for many central heating boilers etc. Above
>> that will damage them. A fitting blew off the mains supply in my
>> mothers flat at somewhere between 7 and 11 bars. Three flats
>> uninhabitable for 18 months and £200k insurance bill. No liability to
>> the water company. Partially closing the main supply valve reduces
>> flow, (and make noise) but does nothing to reduce pressure. You need a
>> reducer on the system if it is above 4 bars. The big step down valves
>> on the water mains they install now are not fail safe and have a habit
>> of failing by giving full pressure - 11 bars etc. Not good for your
>> system. The design rating of copper pipe is 12 bars but the fittings
>> etc are your weak point. If your system is going to see over 4 bars it
>> needs to be properly pressure tested and certified to take max
>> pressure + 20%. This countries standards are so bad it makes me weep,
>> (my pipework as well).
>>
>
> 4 bar is for the sealed system. Mains pressure can be higher than that.
>
> A pressure regulator only really works with a flow through it.
> The
> static pressure (when no flow) will always be higher than the set point
> (although not necessarily the fill input pressure - that depends on the
> volume of pipework downstream). The downstream plumbing must be able to
> handle the static pressure, not just the regulators set point pressure.
>
For example as I found out recently my mains pressure HW cylinder has a
regulator on the input. When the pressure rises above 2.1 bar it shuts
off flow into the tank completely. There is an air bubble pressure
maintainer so that there is 'elasticity' in the system.
The valve on your loo shuts off input completely. That does not mean the
cistern is at 10 bar!
You are thinking of flow reduction as a means to achieve pressure
reduction. Then what you say applies, but that is not what a proper
pressure reducer does.
--
"Strange as it seems, no amount of learning can cure stupidity, and
higher education positively fortifies it."
- Stephen Vizinczey
Chris B
> On 05/04/2019 10:09, Andrew Gabriel wrote:
>> On 04/04/2019 18:41, whi...@gmail.com wrote:
>
>>
>> A pressure regulator only really works with a flow through it.
>
> Not so.
>
>> The static pressure (when no flow) will always be higher than the set
>> point (although not necessarily the fill input pressure - that depends
>> on the volume of pipework downstream). The downstream plumbing must be
>> able to handle the static pressure, not just the regulators set point
>> pressure.
>>
> That is just plain WRONG.
pedantic he is being
http://www.beswick.com/basics-pressure-regulators
shows the principle of zero flow rate regulators and goes on to define
Lock Up Pressure
“Lockup pressure” is the pressure above the set-point that is required
to completely shut the regulator valve off and insure that there is no flow.
But I suspect that for domestic plumbing applications the difference
between lock up pressure and set point pressure will be lost in the noise.
>
> For example as I found out recently my mains pressure HW cylinder has a
> regulator on the input. When the pressure rises above 2.1 bar it shuts
> off flow into the tank completely. There is an air bubble pressure
> maintainer so that there is 'elasticity' in the system.
>
> The valve on your loo shuts off input completely. That does not mean the
> cistern is at 10 bar!
>
> You are thinking of flow reduction as a means to achieve pressure
> reduction. Then what you say applies, but that is not what a proper
> pressure reducer does.
>
--
Chris B (News)
mdria...@gmail.com
rab...@waitrose.com
rab...@waitrose.com
Dave Liquorice
>> Today I measured my incoming mains water pressure to be a little
over
>> 10 bar. About 145 PSI. About 100 metres "head"
device?
Most (metal) domestic plumbing bits are only rated to 10 bar. Plastic
and hot a lot lower. A little bell is ringing that says the maximum
mains pressure ought to be about 6 bar. See what the Ofwat site has
to say?
--
Cheers
Dave.
The Other John
> You are lucky we have only 1.2 Bar
still alive!)
--
TOJ.
Tim+
Brian Gaff (Sofa)
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