Flow restrictor for monobloc tap unit

[Ron Gamma]

Hi,

I have purchased a monobloc tap that will be fitted to a HP cold (rising main) and LP hot (gravity) arrangement.
According to the installation instruction I need to fit a non-return valve and flow restrictor setup.

Presumably I need non-return valves on both feeds and the flow restrictor on the cold only.

What parts do I need (assume Wickes or B&Q as supplier) and how would I size the flow restrictor.

It will all be in 15mm copper with solder ring connections up to flexible, braided stainless, tap connectors with service joints. As the last 3 foot of piping will be partly visible this will be done in chromed tube so any item needs to be bright and shiny to match.

 

[Mike2007]

The non-return valves are correct, as this is mainly due to water regulations. But if you put a PRV (pressure reducing valve) into the 15mm (1/2 inch) cold supply this cures the effect of cold water pushing up the hot pipework (what the check valves are meant to prevent).
A PRV is quite chunky and would need to housed in boxing somewhere and placed as to service your bath taps as well (leave electric shower/WC full mains). They have a screw to reduce water down to low level, try Plumbworld or somewhere but not in a DIY shed!