kitchen plumbing... isolations, check valves etc

[shd1970]

Can anyone confirm please the regs for installation of single or double check valves, isolation valves, drain offs etc in a kitchen.
Also, any mandatory requirements for fitting stop cocks too
FWIW, I will be using a Philmac connector to convert from black mains down to 15mm

I am currently fitting a new kitchen so wanted to make sure my new pipe work adheres to any standards laid down

Many thanks in advance

 

[Madrab]

In short:-

• If the taps are dual flow/separate taps and have a suitable air gap then backflow protection isn't required. Mono, mix in the body, should have backflow protection.
• All outlets/fittings should have a means of isolation for servicing without the need to drain down excess water.
• Mains should have isolation, backflow protection and drain down capability.
• Any outside supply should have separate isolation, CAT5 backflow protection and drain down.

 

[shd1970]

thanks for previous reply Madrab and sorry for delay in replying....
i have a few further questions below in red...

In short:-

• If the taps are dual flow/separate taps and have a suitable air gap then backflow protection isn't required. Mono, mix in the body, should have backflow protection.

so it is a mono, so can you confirm if both H & C would require a check valve (double or single) please ?

• All outlets/fittings should have a means of isolation for servicing without the need to drain down excess water.

so i take this as meaning to have an isolation value, immediately followed by a drain-off, correct ?

• Mains should have isolation, backflow protection and drain down capability.

so immediately after my stop-cock, i need a check valve (double or single) and if so, surely this will affect pressure ?
also, i don't think that i have one already (see enclosed photo)

• Any outside supply should have separate isolation, CAT5 backflow protection and drain down.

 

[Madrab]

• If it's a typical monobloc mains mix in the body tap then by the book you'd stick a single check valve/nrv on each.

• Nope - it just means that each outlet would use it's own ISO/Service valve. That would allow individual outlet servicing without the need to isolate the mains and then possibly draining off the pipework before opening up the pipe.

• Yes, it can affect pressure and that then all depends on the dynamic pressure/flow that your mains can deliver as to how much impact to the delivery you actually notice .... but you asked about the regs and 'by the reg book' the mains should be protected against backflow using a double check valve.

Is that a snapped dual valve mains tap with the integrated drain off? I presume that the mains flows upwards and your working mains stop tap is at the top of the pic? Can't see what's above that ....anything?

 

[shd1970]

thanks for reply madrab and sorry for delay

correct - yes, the mains flows upwards
there is nothing after the stop tap

re: "is that a snapped dual valve mains tap with the integrated drain off ?"....i have no idea but here is a better photo so awaiting your advice

If it is one of those, what's its purpose and do i need one ?

My plan this weekend is to turn off the water at the end of my drive, empty the system, make a clean cut of the black akethalene pipe, attach a Philmac connector to drop it down to 15mm copper, and redirect the akethalene pipe so that its flush with the floor back to the wall (rather than just sticking up in the middle of the kitchen) and then fit a new stop tap

Well that's the plan !

so my kitchen units fit nicely over the top and rather than cutting holes and sections out of my new units

 

[Madrab]

Yes that's an old integrated valve, if you're going to cut the alkathene down and re-do it all then no bother with taking all that away and renewing. the drain off should be above the stop tap or downstream of the tap. Might be easier with a full bore WRAS approved ball lever valve, rather than a stop tap.

 

[JohnD]

I wouldn't cut it flush with the floor, it's useful to have enough to get hold of, for example if one day you need to replace the valve you're about to fit. Especially if the end needs trimming again.

 

[shd1970]

Might be easier with a full bore WRAS approved ball lever valve, rather than a stop tap.

I have a brand new/unused Pegler PB300 with the following text on the blue handle :

Pegler
GAS FAMILIES 1-2-3
PB300
WRAS EN331 + A1

and this stamped on the body of the valve itself :

15MM PN16
EN331 MOP5 DN15


Will this do nicely instead of a traditional stop cock then ?

 

[shd1970]

I wouldn't cut it flush with the floor, it's useful to have enough to get hold of, for example if one day you need to replace the valve you're about to fit. Especially if the end needs trimming again.

Thanks for the reply JohnD
To be clear, I plan to cut as little off the Akathalene as possible so i can have a nice smooth curve under the unit and leave plenty to play with and as you say, in case i need to trim it back in the future

Thanks again

 

[Madrab]

Pegler PB300

Yup, that'll be fine.