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How to vent a floor sink when the nearest wall is ~10' away?

Michael.L

Michael.L

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May 10, 2018
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206
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Boulder County, CO
I'm laying out the floor plan for a small cafe. There will be a coffee bar at the service counter with a 3-compartment sink. The 3-comp sink's drain will be indirectly plumbed to a floor sink below with a required air gap. But the closest wall is 9.6 feet from the location of this floor sink. Is it acceptable for the vent to be that far from the floor sink trap? Do I just upsize the fixture arm drain pipe to ensure that the vent connection opening remains above the trap weir?
 
mtlogcabin said:
If the 3 compartment sink is also being used as a food prep sink then it should be going to a grease interceptor
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It's not a food prep sink, but it will be used to wash out milk steaming jugs and blender jars. It will be drained to our grease interceptor.

mtlogcabin said:
3 " drain will allow 12 feet from the trap to the vent
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Are you sure? According to this graphic, a 3" drain will only allow a max trap arm length of 6 feet, and that I'd need a 4" or larger to get the max trap arm length to 10 feet.

0235deebbcb5528113ebc320714b1b48.jpg
 
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Michael.L said:
One reason is that they tend to make a noise like a "whoopie cushion." Not exactly what you want customers to hear at your cafe's service bar.
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I can understand that.

mtlogcabin is spot on, if your using local jurisdiction uses IPC then you will be okay. Chapter 9, Venting from the IPC allows up to 12ft when using 3" drain at 1/8" slope.
 
James Davis said:
the majority of inspectors don`t like/allow AAV`s
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The UPC does not allow the use of an AAV. However they can be permitted under alternate materials and methods which we have done on a case by case decision for existing buildings

The IPC does allow them so unless the AHJ amended that section of the IPC to not allow them then inspector is not following the code and acting upon his personal wants and desires
 
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MT is correct on both accounts. The IPC does allow AAV, but you have to have access. The 3" drain should work just fine, if you want to be on the safe side go to 4" and you will have plenty of air.
 
AAVs are not included in the UPC or the CA Plumbing Code But does not prohibit the use.
Just because they are not included does not mean they are prohibited.

CA allows the AHJ, to use discretion, on a case by case basis. This however, does not extend to commercial use.

upload_2018-8-11_7-41-6.png
 
Air admittance valves let air in but do not let air out. A plumbed vent will prevent air pressure from pushing the water out of the trap. Now I don't know if that is reason enough to ban them but I get the feeling that my jurisdiction is less than impressed.

As an aside, I don't know but I've been told that they do fail.....there was a mold buildup....some colorful stuff of the genus IMUS (It'll Make Us Sick).
I wonder what became of Don.
 
GEEZ. Commercial kitchens with floor sinks have been connected to combination waste and vent systems for decades. You are making this toooo complicated. A single sink can be on a CWV system. The horizontal pipe of a CWV is unlimited in length.
 
We have a drinking fountain in CA that we were supposed to run a loop vent for and forgot/overlooked. The 1.5” drain line cannot be vented conventionally because of a window directly above it’s structural steel building posts on either side. We submitted an RFI (Request For Information) asking for an AAV to be plumbed above the flood plane with an access panel (We’ll see if the architect interprets the “Not for commercial use” in this application).
Saw cutting concrete is sometimes more preferable than a discussion and hen party with the brass...
As a side note, ICE / Sawhorse (because I like your smart-ass frank responses in the few forum threads I’ve read here), how often have you checked for these while inspecting plumbing:
1. Weir of trap to vent wye distances?
2. Vent wye roll to 45 degree offset from waste line?
3. And trap weirs being below the centerline of vertical san-tee inlet?
I can only recall one inspector with knowledge of these items in 20 years ...
 
Bill Ernst said:
As a side note, ICE / Sawhorse (because I like your smart-ass frank responses in the few forum threads I’ve read here), how often have you checked for these while inspecting plumbing:
1. Weir of trap to vent wye distances?
2. Vent wye roll to 45 degree offset from waste line?
3. And trap weirs being below the centerline of vertical san-tee inlet?
I can only recall one inspector with knowledge of these items in 20 years ...
Click to expand...
If you convert those strange terms into English I'll try to answer the question.
 
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