best way to measure mains flow rates/pressure?

[Jennie]

Hi all,
I'd be interested to hear how you all measure mains flow rates/pressure in a house.
I'm soon to install a 10kw electric shower in a friend's house. I'm a student plumber. My tutor has advised me to check the house's flow rates and pressure are enough for the shower.
I've got a flow rate cup and pressure gauge, which I tried out in my own home.
My kitchen tap measured 8 litres/minute, less than the outside tap at 18 litres/minute. I'm aware that iso valves, pipe bends and fittings, and taps themselves can affect the readings.
Ideally, I'm after a quick, easy way to take accurate measurements (without needed to access a bare pipe).
How do you all take these measurements?
Jennie

 

[Avatar]

Get one of these and bang in it on the washing machine tap ideally to get a reading in bar:

Monument Tools Mains Water Pressure Test Gauge | NoLinkingToThis

For an electric shower you need a min of 1 bar usually. Do not worry about flow rate for this!

Also you really need to check the electrical side of the installation for a job like this:

- How far from the consumer unit are you? The type of cable needed will cost an arm and a leg and you will need to have a mind to how it will be routed . . ..
- Does the consumer unit have an RCD? Does it have a spare 'way' on it? if the answer is no to either of these then a new consumer unit could be needed which is £££!

Also you will need to put a 'full bore' isolation valve on the feed for the shower so not to reduce pressure at the point of use . . .

 

[lame plumber]

then turn on a tap to read what the dynamic water pressure is, rather than seeing the standing pressure youll get if you dont, quite a difference normally

 

[SimonG]

I have a pressure gauge that goes onto a washing machine valve. Flow is normally a pop bottle and stopwatch.

 

[AWheating]

be careful when testing pressure at washing machine taps or bib taps. If they have a check valve built in it may give you a false reading.

 

[dancinplumba]

Strugglling with this, flow yes, but pressure ??

 

[Phil_Plumb]

the same tool sold by screwfix is 4 quid cheaper at toolstation

 

[lame plumber]

Google Image Result for http://www.schofields.ltd.uk/blog/wp-content/uploads/2010/05/iStock_000006909815XSmall1-300x235.jpg

should have checked the pressure, probably had a good flow though

 

[dancinplumba]

Google Image Result for http://www.schofields.ltd.uk/blog/wp-content/uploads/2010/05/iStock_000006909815XSmall1-300x235.jpg

should have checked the pressure, probably had a good flow though

Am talking about AW's comment silly boy

 

[lame plumber]

Am talking about AW's comment silly boy

oooh no offense, just found this lovely phot and thought it might cause concern amongst the plastic brigade, probably iced up if they are worrying

 

[dancinplumba]

Do like the link tho