# RP drain question



## Ptturner91 (Oct 13, 2012)

Do you have an RP backflow preventer with a air gap could you connect it directly to a drain with a ptrap? It has the air gap right below the device so would that be legal ?


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## Shoot'N'Plumber (Apr 27, 2013)

Yes, assuming nothing against yur local code, they make the RP drain adapters that are already sized for the proper air gap per size of assembly at the device. So yes the drain can be direct connected to a trapped drain line. Think of the drain adapter ( zurn makes a model) as a floor sink, which has a trap with which a commercial sink would drain into with said air gap.


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## Plumbus (Aug 4, 2008)

As long as you maintain an airgap of at least 1", it qualifies as indirect waste when discharged into the building drainage system,.


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## Ptturner91 (Oct 13, 2012)

Ok awesome thanks guys


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## newyorkcity (Nov 25, 2010)

I'm not so sure. There may be a risk of bacteria creeping up the air gap fitting in the event of a stopage.
I could be wrong, but I think you still need an air gap after the air gap.


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## Shoot'N'Plumber (Apr 27, 2013)

newyorkcity said:


> I'm not so sure. There may be a risk of bacteria creeping up the air gap fitting in the event of a stopage.
> I could be wrong, but I think you still need an air gap after the air gap.


It's easy to imagine that a double air gap would be the way to go, however it's exactly why those adapters were made as not every install location has the benefit of a floor drain or somewhere to safely discharge. I still on many occasions use a homemade air gap assembly plumbed into my drain piping, followed by a trap, then direct into the drain. The primary issue with this is the trap drying out on occasion causing odors. But if there's a trapped floor drain of some kind that can handle he discharge requirements, this will always be my first choice (double air gapped).


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## Fast fry (May 19, 2012)

Move rp to above the sink and pipe discharge into it.


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## Gargalaxy (Aug 14, 2013)

We installed a new draft tap system and we made a homemade air gap for the hoses drain (2 total, one was clear 3/4"OD clear tubing and second was a 3/8").


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