Backflow Preventers vs Vacuum Breakers 1

[John_187]

I recently inherited a project where one of the buildings does not have a backflow preventer at the water entry room. I thought this was extremely unusual. It is a commercial building, and I've always put one in. The designer told me the reason is that each plumbing fixture in the building supposedly is intended to have vacuum breakers.

Is that permitted, to replace the function of a backflow preventer for the whole building with individual vacuum breakers at the building?

Thanks

 

[PEDARRIN2]

The requirement to install backflow preventers is relatively new (last 10-20 years). If the building predates that, it might not have one, although I believe AHJ's have required them to be retroactively installed after the fact.

But to your question, vacuum breaker cannot replace backflow preventers for building service. The use of vacuum breakers only prevents back siphonage by breaking the vacuum caused by the siphon, but will not prevent back flow. A backflow preventer (DC or RPZ) will prevent both.

 

[John_187]

Ok, thanks for the response