power showers - pipe size

[mp]

hi all.

installing a power shower but the present feed pipes to the shower mixer are

15mm, from what I've read it seems that 22mm is better, but the pump m'frs don't say whether 15mm is ok.

If possible would it be best to get a lower bar pump (eg 1 or 1.5 bar)? A higher bar pump would only put pressure on the 15mm pipe welds and might not even deliver more water - am I right?

Thanks for the advice,

MP

[John Stumbles]

15mm should be OK. The output of the pump will not be enough to strain soldered (not welded) joints. If you have a very high flow shower e.g. a whole-body panel then the higher flow will result in a greater pressure drop in the pipework than at lower flows but even so the losses in the pipework won't make much difference overall.