"John" wrote in message
...

Southern Water will do a free check of the water pressure at the
stopcock
and at your kitchen sink. Possibly your water board will do the same. I
think that they are obliged to ensure that the pressure is good at the
stopcock but they are not responsible for the pipe between there and
your
house.

Im thinking (back to A level physics) but not getting anywhere. Can anyone
help/

Water pressure is not the same as water flow.

i.e I could get 25ltrs a min at a very low pressure, or 1 ltr a min at
very
high pressure

If the incoming water pipe is at say 15mm an at 3 bar, and the stopcock is
partially closed the the amount of water from the tap will be reduced,
from
what I remember however the pressure will remain constant, even if the
stopcock would only be fractionally open when there is no demand for
water.

If, say the kitchen tap is fully opened (and all pipework in the house
except for the supply pipe) were 22mm then the pressure on the tap may
fall
(i.e the water flow aceheiveable from the 15mm pipe will have a larger
capacity pipe, so will reduce in pressure to compensate) - if the tap is
slighly open - i.e reducing the flow rate to below that acheiveable from
the
supply - then pressure will be the same?

Am I right?



The pressure will remain the same in any pipe connected to the supply set at
3bar and the only thing that will change is the flow rate. The only thing
to happen when you increase the pipe diameter, is that the water takes
longer to flow through it in accordance with the increase in volume of the
pipe and would seem as though you had a reduction in the pressure, but in
actual fact the water is still being supplied at 3bar.