New Lever tap for kitchen query

[BobbyJoe]

Good morning,
I am not able to take photos of the following query but will describe it in as much detail as possible. At the moment I have an old style mixer tap in the kitchen (the one where you turn the handles) and the pipework seems fine (white pipes/wastepipe etc) the copper ones linked to the tap look a little green as does the bronze stopcock. valve.
Due to having trouble using the turning taps I want a lever tap installed;

I would like to know on the copper pipes should a Non Return Valve or Single Check Valves be installed?
Are flexi hose pipes okay to be attached under the sink to the copper pipes?

I would like the pipework and its fixings to be current with building regulations, so anything that should be there I would appreciate knowing about so I can tell the plumber what I want.
Any information or advice would be appreciated thank you

 

[SimonG]

What hot water system do you have? Combi? Unvented? Or Vented with an airing cupboard?

Taps need to be suitable for the pressure you have.

 

[BobbyJoe]

Hi thanks for the reply, I have a brand new combi boiler in the kitchen and the water is cold mains fed. I believe about 10 or more years ago there was a water tank in the flat but was removed ages ago as I just moved in a few months ago.
That is one of the reasons I would like to change the kitchen tap and ensure it is updated with todays regulations besides the current tap is leaking and isn't working as well as it should, thanks.

 

[moonlight]

If you have a combi, you can fit taps with ceramic or washer valves. It's good practice to fit service valves to the supply's for maintaining purposes. If you fit a tap with a pull out spout, a non return valve should be fitted. Also taps that are not bi-flow mixers, imported taps can fall into this category.

 

[BobbyJoe]

Good morning I was reading the answer in bold at the bottom of the page and wondered if it would apply to my situation and which fittings should be installed to the kitchen sink pipes.
My cold water is fed via the mains and my hot is via the combi boiler, at the moment the kitchen tap needs to be replaced the copper pipes don't have any isolation valves/check valves or NRV on them.
I read the following and would appreciate it if someone could offer advice and point me in the right direction.
For my own education what are fluid risk categories and how do they impact you? thank you.

"You require single check valves on each feed even though they are the same pressure. Section 6 R15.13.2.a second paragraph. Where a combination tap or mixer with water mixing in the body is used with balanced pressures (that is, both inlets are fed from supply pipes or both are from storage) the cold side' is now rated as fluid risk category 1, and the 'hot side' is now rated fluid risk category 2, and single check valves should therefore - according to the Regulations - be installed on both sides."

 

[moonlight]

You will only need check valves if the water mixes in the body of the tap.