will one way valve cause pressure drop

[AJ16]

I'm running a new supply to two outside taps but rather than having bib taps with non return valves, I got them without and plan to fit an inline NRV in the utility room where the cold water supply is to be intercepted. One tap is about 4 metres from the valve, the other is down the garden about 25 metres or so.
Both taps fed from 25mm bore MDPE pipe. I have got 6 bar mains pressure. Will the one way valve affect the further tap greatly or should I swap to normal NRV bib taps? Thanks

 

[Mike Jackson]

NRV bib taps don't comply with the water regs so you can't use them. With 6 bar it won't make a lot of difference anyway.

Mike

 

[AJ16]

someone said in an earlier post though that NRVs need to be inside to protect them from freezing. Is this not the case then?

 

[Bernie2]

Hmm!

Double check valves are required for hose union taps. The thing is the regs do say that on new installations check valves should be inside and frost protected.

The thing is if I read you right, your proposing to make one branch connection in the 25mm MDPE main fit the NRV and then run the pipe outside supplying the first tap then on to the second tap?

There is a problem in that the first tap or second tap would not be protected from one another. So supposing back syphoning did occur the substance sucked up from say the far tap could fill the pipe and come out of the near tap.

Admittedly it would not get into the mains water supply because that would be protected by the double check valve.

But it may provide a health risk in other ways. So the official way to find out if you can do it the way you want too, is to ask your water provider.

I would have split the supply inside and put a double check valve on each tap supply myself, stops any hassle that way.