"John" wrote in message
...
OP he

Thanks for all the posts about how to improve flow-through in my kitchen
HW tap. I didn't realize (and certainly was never told by MFI!) that my
fancy tap should really be pressurised! I will be looking at the pump
suggested by a couple of posters, and also at the cheaper alternatives
suggested.

If it is a spray attachment tap then they usually need 1.5 bar to operate
the spray. This means a pump is around 2 bar minimum, which is usually an
expensive pump. A shower pump will not do, as they are designed for
continuous running for 15 to 30 mins 3 to 4 times a day. A kitchen tap may
be turned on for a few seconds then off then on again. This may lead to
early failure on a pump not designed for this operation.

Personally I would abandon the taps and get a non-spray attachment high or
low pressure mixer.

Just for info: I'd thought about increasing the diameter of the
feed-pipe to 22mm because I was thinking in terms of weight of water
coming to the tap.

That will not make the tap work properly.