Special venting for island sink

[Marc]

I'm familiar with the return loop required on island sinks where a traditional vent is not possible. This plumber has invented something I've not seen before:

Click to Enlarge

16.65 KB

Anyone know if it's kosher? It's a three incher instead of the usual 2 inch drain paired with a 1 1/2 inch loop/return.

I've written up the missing trap.

Marc

[Jim Katen]

Someone with access to old JLC articles might find one from the late '90s on this topic. As I recall, one of the solutions that they proffered was to use a pipe two sizes larger than the fixture drain.

[Marc]

I'll check.

Marc

[mjr6550]

I'm familiar with the return loop required on island sinks where a traditional vent is not possible. This plumber has invented something I've not seen before:

Click to Enlarge

16.65 KB

Anyone know if it's kosher? It's a three incher instead of the usual 2 inch drain paired with a 1 1/2 inch loop/return.

I've written up the missing trap.

Marc

I would say that regardless of what you find in JLC, if its not in the code its not correct. Unless of course, the local AHJ says its ok. And that does not mean it is correct.

I used an AAV to vent the kitchen sink in my island. I have not had any concerns in 2+ years. I know that some plumbers and inspectors don't like them, but they meet code and seem to work.