water pressure testing
 

what is the recognised way of testing mains water pressure. I am looking at
having an electric shower fitted and the pressure is affecting my choice.

"therebel" wrote in message
...
what is the recognised way of testing mains water pressure. I am looking at
having an electric shower fitted and the pressure is affecting my choice.


A web search for the word "Manometer" will show you what's needed. But an easy
test is placing your thumb over the kitchen sink cold tap, and then slowly turn
it on. At a certain point you won't be able to hold the pressure back, and this
shows a good mains water supply pressure. A good mains water supply pressure is
what's needed for a good electric instant shower.

The next thing you need to find out for an electric instant shower is the
electrical supply routing. A good shower is anything above 8.5kW and mat need
to be supplied with large cables if the routing demands it.

Hope this helps a little.

In message , therebel
writes
what is the recognised way of testing mains water pressure. I am looking at
having an electric shower fitted and the pressure is affecting my choice.

Request your local water authority to test it

--
geoff

In an earlier contribution to this discussion,
therebel wrote:

what is the recognised way of testing mains water pressure. I am
looking at having an electric shower fitted and the pressure is
affecting my choice.

To measure static pressure, you need a pressure gauge. Screwfix do one for a
tenner or so which will attach to any outside tap which has a threaded spout
to take a hose attachment.

However, static pressure (at zero flow) doesn't tell you very much because
if there are restrictions in your supply pipe (long thin pipe, etc.) the
pressure may drop dramatically when you turn a tap on. So you also need to
measure *flow* - which you can do with a bucket and stopwatch. Weigh the
bucket empty and then direct the full flow of the kitchen tap into it for a
timed period and then weigh it again. If the timed period is one minute, the
weight difference in Kg gives the flow in litres/min.
--
Cheers,
Set Square
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"BigWallop" wrote:


"therebel" wrote in message
...
what is the recognised way of testing mains water pressure. I am looking at
having an electric shower fitted and the pressure is affecting my choice.


A web search for the word "Manometer" will show you what's needed.

Which will be absolutely useless unless:

a) you use a super dense fluid

or

b) possess a huge manometer (ooh err)

Can I suggest the use of a pressure gauge that reads 0-5 bar or if
this is not available then build a manometer around 200 ft high


--

"Set Square" wrote in message
...
In an earlier contribution to this discussion,
therebel wrote:

what is the recognised way of testing mains water pressure. I am
looking at having an electric shower fitted and the pressure is
affecting my choice.

To measure static pressure, you need a pressure gauge. Screwfix do one for
a
tenner or so which will attach to any outside tap which has a threaded
spout
to take a hose attachment.

However, static pressure (at zero flow) doesn't tell you very much because
if there are restrictions in your supply pipe (long thin pipe, etc.) the
pressure may drop dramatically when you turn a tap on. So you also need to
measure *flow* - which you can do with a bucket and stopwatch. Weigh the
bucket empty and then direct the full flow of the kitchen tap into it for
a
timed period and then weigh it again. If the timed period is one minute,
the
weight difference in Kg gives the flow in litres/min.
--
Cheers,
Set Square
______
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You may also find a rather large difference in pressure between 8.00am in
the morning and 3.00pm in the afternoon!

In message , BigWallop
writes

"therebel" wrote in message
...
what is the recognised way of testing mains water pressure. I am looking at
having an electric shower fitted and the pressure is affecting my choice.


A web search for the word "Manometer" will show you what's needed.

So you have the choice - water and a very tall tower, a significant
quantity of mercury and a small tower or something in between


--
geoff

BigWallop wrote:


"therebel" wrote in message
...
what is the recognised way of testing mains water pressure. I am looking
at having an electric shower fitted and the pressure is affecting my
choice.


A web search for the word "Manometer" will show you what's needed.

You can make your own with some clear plastic tubing filled with water.
It'll need to be 30 metres or so high, though.

"BigWallop" wrote in message
. uk...

"therebel" wrote in message
...
what is the recognised way of testing mains water pressure. I am looking
at
having an electric shower fitted and the pressure is affecting my choice.


A web search for the word "Manometer" will show you what's needed. But an
easy
test is placing your thumb over the kitchen sink cold tap, and then slowly
turn
it on. At a certain point you won't be able to hold the pressure back,
and this
shows a good mains water supply pressure. A good mains water supply
pressure is
what's needed for a good electric instant shower.

The next thing you need to find out for an electric instant shower is the
electrical supply routing. A good shower is anything above 8.5kW and mat
need
to be supplied with large cables if the routing demands it.

Hope this helps a little.



Unless you have access to a Mercury Manometer at around thirty feet tall or
a water manometer at around 300 feet I would suggest you use a bourdon gauge
(Dial type) which is fairly easily obtained from a decent plumbers merchant
for around a tenner. However standing pressure is one thing, dynamic
pressure under flow conditions is entirely different as it may be that the
pipework restricts the flow at the outlet point.

In article ,
John wrote:
[snip]
.......However standing pressure is one thing, dynamic pressure
under flow conditions is entirely different as it may be that the
pipework restricts the flow at the outlet point.

Below are the quoted requirements from our electric
shower booklet.

" ... a mains water supply with a minimum running
pressure of 1 bar (14.5psi) at a minimum flow
rate of 8 litres per minute and a maximum static
pressure of 10 bar (145 psi)."

" ..... can be taken from a cold water storage cistern
provided there is a minimum head of 30m above the
sprayhead. It must be an independant supply to the
shower only."

That second possibility is a little unrealistic for
most houses.

--
Tony Williams.

In an earlier contribution to this discussion,
Tony Williams wrote:


Below are the quoted requirements from our electric
shower booklet.

" ... a mains water supply with a minimum running
pressure of 1 bar (14.5psi) at a minimum flow
rate of 8 litres per minute and a maximum static
pressure of 10 bar (145 psi)."

" ..... can be taken from a cold water storage cistern
provided there is a minimum head of 30m above the
sprayhead. It must be an independant supply to the
shower only."

That second possibility is a little unrealistic for
most houses.

It's cobblers, anyway! 1 bar requires a head of about 30 feet - *not* 30
metres!
--
Cheers,
Set Square
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"Set Square" wrote in message
...
In an earlier contribution to this discussion,
Tony Williams wrote:


Below are the quoted requirements from our electric
shower booklet.

" ... a mains water supply with a minimum running
pressure of 1 bar (14.5psi) at a minimum flow
rate of 8 litres per minute and a maximum static
pressure of 10 bar (145 psi)."

" ..... can be taken from a cold water storage cistern
provided there is a minimum head of 30m above the
sprayhead. It must be an independant supply to the
shower only."

That second possibility is a little unrealistic for
most houses.

It's cobblers, anyway! 1 bar requires a head of about 30 feet - *not* 30
metres!
--
A water manometer must be taller than a house as:-

1. The water must get into loft storage tanks in many properties.
2. I have hosed down the moss in my last house using house pipe on the roof
and had no water pressure problems up there.

John Stumbles wrote:

You can make your own with some clear plastic tubing filled with water.
It'll need to be 30 metres or so high, though.

So if it squirts out the end you have more than 3 bar pressure ?

--
http://gymratz.co.uk - Best Gym Equipment & Bodybuilding Supplements UK.
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In an earlier contribution to this discussion,
Ian_m wrote:

"Set Square" wrote in message
...
In an earlier contribution to this discussion,
Tony Williams wrote:


Below are the quoted requirements from our electric
shower booklet.

" ... a mains water supply with a minimum running
pressure of 1 bar (14.5psi) at a minimum flow
rate of 8 litres per minute and a maximum static
pressure of 10 bar (145 psi)."

" ..... can be taken from a cold water storage cistern
provided there is a minimum head of 30m above the
sprayhead. It must be an independant supply to the
shower only."

That second possibility is a little unrealistic for
most houses.

It's cobblers, anyway! 1 bar requires a head of about 30 feet -
*not* 30 metres!
--
A water manometer must be taller than a house as:-

1. The water must get into loft storage tanks in many properties.

True. For a typical 4 bar pressure, it would need to be at least 120 feet
tall.

But that's not the point of this part of the thread. I was commenting on the
fact that the shower spec is wrong in implying that you need a 30 metre head
to get 1 bar at the shower.
--
Cheers,
Set Square
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So if it squirts out the end you have more than 3 bar pressure ?

Yes, and if you turn on a tap and it still squirts, the dynamic pressure is
pretty good, too!

Christian.

In article ,
Set Square wrote:

In an earlier contribution to this discussion,
Tony Williams wrote:
[snip]
provided there is a minimum head of 30m above the


It's cobblers, anyway! 1 bar requires a head of about 30 feet -
*not* 30 metres!

My typo. Try 10m.

--
Tony Williams.

In an earlier contribution to this discussion,
Tony Williams wrote:

In article ,
Set Square wrote:

In an earlier contribution to this discussion,
Tony Williams wrote:
[snip]
provided there is a minimum head of 30m above the


It's cobblers, anyway! 1 bar requires a head of about 30 feet -
*not* 30 metres!

My typo. Try 10m.


That's better!

--
Cheers,
Set Square
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On Wed, 18 May 2005 21:32:14 GMT, "therebel"
wrote:

what is the recognised way of testing mains water pressure. I am looking at
having an electric shower fitted and the pressure is affecting my choice.

Contact the water board. Southern water will test your pressure for
free.

sponix

On Thu, 19 May 2005 15:00:14 +0100, "Set Square"
wrote:

It's cobblers, anyway! 1 bar requires a head of about 30 feet - *not* 30
metres!

Correct. 1 bar is 10 metres or 14.2 psi.

sponix

In article ,
s--p--o--n--i--x wrote:
On Thu, 19 May 2005 15:00:14 +0100, "Set Square"
wrote:

It's cobblers, anyway! 1 bar requires a head of about 30 feet - *not* 30
metres!

Correct. 1 bar is 10 metres or 14.2 psi.

Crikey - that's an old post you're replying to? ;-)

--
*A closed mouth gathers no feet.*

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

"s--p--o--n--i--x" wrote in message
...
On Thu, 19 May 2005 15:00:14 +0100, "Set Square"
wrote:

It's cobblers, anyway! 1 bar requires a head of about 30 feet - *not* 30
metres!

Correct. 1 bar is 10 metres or 14.2 psi.

14.7 psi