# 13D backflow preventers



## retire09 (Mar 4, 2011)

Does a 13D stand alone wet system with no anti freeze require the installation of a back flow preventer?

I am told that they do, but the only requirement I can find in 13D involves antifreeze.

Can anyone give me a reference section in 13D?


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## Mac (Mar 4, 2011)

My 2007 13D does not require backflow protection - however the Annex (explanatory info) advises that backflow and metering is subject to local regulation, and a diagram indicates a "rubber faced check valve" as being optional.


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## pwood (Mar 4, 2011)

none required. some ahj will require the system to have a loop that would hook up to a water closet to keep the water from stagnation.


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