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