DCV on mains AND outdoor tap?

[jpowell79]

Renovating the kitchen at the moment and thought it was a good opportunity to rip out the old water pipes that had seen better days and fit fresh ones. My main water comes up from under the stairs so I’ve fitted a pegler stopcock before it heads into the kitchen. There’s no sign of a DCV before it gets to the sink (before heading off around the house) but I can see an old check valve on the feed to the outdoor tap. Planning to cut that off and replace with a new DCV as well as single valves for the hot/cold mixer tap, washing machine and dishwasher.

so the question is, do I need another DCV on the mains feed before it even gets to the sink? Surely I’m pretty much covered for contamination with all the other check valves? I’ve heard mixed messages on sites.... some say a DCV MUST be fitted immediately after the stopcock.... some say you don’t need it with all the other valves..... so do I need it or not?

not worried about the cost or fitting it.... more worried about reduced flow, so if I don’t need it, I won’t bother fitting one.

 

[picasso]

You dont need a check valve on the incoming main.

 

[Madrab]

As far as the regs are concerned then it depends.

If you are say in a block of flats where everyone is using the same rising main then yes it is best practice that there is a double check valve installed downstream of the stop tap.

It also is dependent on whether there is a risk that the mains can drop in pressure creating the possibility of backflow, say in rural areas or areas where the mains pressure is known to fluctuate.

 

[jpowell79]

cheers!

 

[JimCrow]

It has been a requirement with Scottish Water for years now to have a DCV on all new supplies, they wont connect you otherwise.