"Martin Pentreath" wrote in message
oups.com...
Hi,

I have pretty low mains water pressure (just over 1 bar) and a fairly
low flow rate to the taps. Thames Water won't do anything because they
say it is within acceptable limits. I've just been looking at these
things:
http://www.machinemart.co.uk/product...5&g=122&r=2158
It would be an easy job to put one into the incoming main in the
cellar, but would it make any worthwhile difference. Rate of flow is
more important to me than pressure, especially when more than one tap
is open. I've never quite got my head around the difference between
rate of flow and pressure, but I don't see how one of these things
could actually suck more water out of the incoming supply in order to
increase the rate of flow.

It's illegal to pump water out of the mains supply, this is so dirty water
does not get sucked in the leaking pipes.

You can however, pump water from a tank, so, if you have a tank in the loft,
you can stick a pump on the outlet from this (and the hot water cylinder, if
you have one)

Pressure is the force the water is trying to get out of the pipe, so with
everything off, the pipes and taps are holding back 1 bar of pressure, 1 bar
is like having a tank of water 10 meters high, so if you had a 15mm pipe
connected to a tank of water 10 meters in the air, the pressure would be
about 1 bar, however, if you had 22mm pipe connected, the pressure will be
the same, but the flow will be greater. 10mm pipe will still be 1 bar, but
the flow will be far less.

Have you made sure all you stopcocks are fully open?
If you have any of the silver service valves
(http://www.screwfix.com/app/sfd/cat/...29674&id=17447 or
http://tinyurl.com/mcdg7
these will reduce the flow quite a lot, as the hole in the moving ball is
only about 10mm
Your main stopcock may also be restricting the flow.

If it is causing you a big problem, I would do the following...

time how long it takes to fill a bucket from your kitchen tap, and also your
outside tap (if you have one)

Turn off the water at the stopcock
Disconnect the pipe to the rest of the house
connect a piece of pipe (plastic would be best here)
do the test again here, if there is no significant improvement, it may be
the stopcock

If this is the case, then turn the water off in the road
remove the stop cock and repeat the test - if again there is no significant
improvement, then you are stuffed!


Sparks...