Mixer taps and check valves

[Tezzer2022]

Hello,
I have a few mixer taps to install in bathrooms and kitchen. The kitchen tap also has a wondering spray arm capability. On researching something else, i stumbled across people saying that a check valve should be placed on the cold mains feed. How can I tell if the mixer taps/spray arm mix the water in the body of the taps or at the spout as I guess this would determine whether a check valve is potentially needed? This is part of a direct cylinder setup.

 

[Basher]

You can generally tell a tap that mixes at the spout outlet because there is a co-axial piped spout, the hot coming from the pipe in the middle and the cold from outside that. If you take the spout off you will see it has separate waterways for H & C and multiple O-rings for the seals.
If you are talking about a kitchen tap with a hand held spray on a hose, all the ones I've come across have a single hose that carries the mixed H & C, the mix taking place immediately after the taps, so they require the check valve.

 

[Tezzer2022]

You can generally tell a tap that mixes at the spout outlet because there is a co-axial piped spout, the hot coming from the pipe in the middle and the cold from outside that. If you take the spout off you will see it has separate waterways for H & C and multiple O-rings for the seals.
If you are talking about a kitchen tap with a hand held spray on a hose, all the ones I've come across have a single hose that carries the mixed H & C, the mix taking place immediately after the taps, so they require the check valve.

Hello Basher,
Thanks for the reply. Very helpful.
Is there such a thing as a flat faced isolation valve with a built in check valve.
The problem I can see introducing a check valve on the cold feed is the resulting end of the NRCV will have the sharp edge when connecting to my flexi tap connectors. Is there a resolution to this?

 

[plumbingservices]

Yes, there are isolation valves with built-in check valves.
Regarding your concern about the sharp edge at the end of the non-return check valve (NRCV) when connecting to flexi-tap connectors, what you can do is :
1. Ensure that you are using flexible tap connectors that are compatible with combination valves or have a design that accommodates the check valve.
2. You can install additional settings or adapters to create a smooth transition.
3. Consult with a professional plumber.

 

[Tezzer2022]

Yes, there are isolation valves with built-in check valves.
Regarding your concern about the sharp edge at the end of the non-return check valve (NRCV) when connecting to flexi-tap connectors, what you can do is :
1. Ensure that you are using flexible tap connectors that are compatible with combination valves or have a design that accommodates the check valve.
2. You can install additional settings or adapters to create a smooth transition.
3. Consult with a professional plumber.

Thankyou. I think I will go with option (2) and introduce a straight through compression brass coupler adapter. I assume a single check valve is sufficient for mixer taps.
As a side note would you be able to recommend a all in one isolation/check valve?

 

[Basher]

Is there such a thing as a flat faced isolation valve with a built in check valve.
The problem I can see introducing a check valve on the cold feed is the resulting end of the NRCV will have the sharp edge when connecting to my flexi tap connectors. Is there a resolution to this?

I know the problem. I've ended up using a flat faced isolation valve after a separate check valve, rather than an all-in-one.
I had a quick Google and I can't see any check valves, with or without isolation, with a flat face, apart from this (which might not be specifically for potable water!)

Firebird Combi Filling Loop Check Valve, 15mm, ACC015FCV | Buy at H.P.W.

Firebird Combi Filling Loop Check Valve, 15mm, ACC015FCV available to buy online, with fast tracked delivery. Heating Parts Warehouse the specialists in plumbing and heating parts and spares.

heatingpartswarehouse.co.uk

 

[Tezzer2022]

I know the problem. I've ended up using a flat faced isolation valve after a separate check valve, rather than an all-in-one.
I had a quick Google and I can't see any check valves, with or without isolation, with a flat face, apart from this (which might not be specifically for potable water!)

Firebird Combi Filling Loop Check Valve, 15mm, ACC015FCV | Buy at H.P.W.

Firebird Combi Filling Loop Check Valve, 15mm, ACC015FCV available to buy online, with fast tracked delivery. Heating Parts Warehouse the specialists in plumbing and heating parts and spares.

heatingpartswarehouse.co.uk

Thanks for having a google.
I think I’ll do something similar and take your advice. Perhaps keep the check valve after the isolation valve. If I can possibly flatten/file the check valve end. Lots of food for thought.
Thanks.

 

[fowlerboi]

Thats what you want

Tesla Brass Compression Adapting Flexible Tap Connectors 15mm x 1/2" 2 Pack - Screwfix

Order online at Screwfix.com. Flexible tap adaptors fit into standard 15mm isolating valves. Suitable for flexible hoses / monobloc tails with ½" swivel nuts. FREE next day delivery available, free collection in 1 minute.

www.screwfix.com

Personally I just file down the sharp edge, takes 5 seconds max

 

[Tezzer2022]

Thats what you want

Tesla Brass Compression Adapting Flexible Tap Connectors 15mm x 1/2" 2 Pack - Screwfix

Order online at Screwfix.com. Flexible tap adaptors fit into standard 15mm isolating valves. Suitable for flexible hoses / monobloc tails with ½" swivel nuts. FREE next day delivery available, free collection in 1 minute.

www.screwfix.com

Personally I just file down the sharp edge, takes 5 seconds max

Thank you.
Good to know that there are options as earlier my options seemed very limited.
Thanks again everyone