So I went inside this Cuban Cafe for some breakfast. I was sitting on the counter where I can see the sink, the coffee maker and the Cuban bread press.

I looked down and noticed they have a stainless steel sink, below that three PVC sanitary tees connected to a drain.





That PVC drain just shoots over to the right side and turns vertically down and ends.



See that? On the floor is some sort of a receptor?

Also, the wall the sinks are against, there is another pipe below the sink (it's partially painted red) that comes out of that wall, and again stops, and a few inches below is a receptor.

What kind of plumbing is this? I assume below the receptor is a trap before it ties into the main drain? Is this how they solve the venting problem?

This can't be "legit" right?



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It is legit. I had to look closely because I plumbed one a few weeks ago and it looked exactly the same. Its called an indirect waste, and it prevents germs and bacteria from coming up thru the drains into the sink used for food prep and dishwashing. There should be a trap underneath the floor, I usually use a 2" trap, with a 4" X 2" reducer and make the standpipe with 4", sort of a funnel.

there must be a grease interceptor in there somewhere.
that set-up would never fly in massachusetts.
can not use PVC for a commercial application. must be copper or cast iron.

Ahhh - me encantaria un cafe Pilon y unas croquetas de jamon

The drain over the floor receptor is not air-gapped, only air-break(ed). Not legit. That drain in the background is probably a condensate drain from a walk-in refrig/ freezer on the back side of the wall.

It is an 'indirect connection" and is required for any sink used for food preparation, and can also be to protect dishes in the sink from back flow and contamination. It is legal, but only when the pipe stops at least one inch above the rim of the "receptor". Not sure what the other one is, but it is also an indirect connection.

quote; can not use PVC for a commercial application. must be copper or cast iron.

that is a "local" requirement. Here ABS, or PVC, is acceptable. But we also have to have vents on our floor drain and sink traps, the interceptor may require a flow control, and the indirect drains cannot hang "into" the hub drain/floor sink.

As a DIYer I have never seen this. Learned something new.

What is the purpose of having this "open" configuration? Since it's a restaurant I can see food waste, teabags, grease, bread crumbs all kinds of junk going down the drain it seems it would likely to stop up and the pipes get slimy...and the water dropping out of the vertical pipe will it not splash around the receptor?

And the receptor is nothing more than a floor drain right? So why not install the receptor such that the outer "lip" is flushed with the floor, so that you can mop the floor and push the dirty water into it?

Packy the reason for not allowing PVC is it due to possibility of restaurants may be emptying a bucket of 400 degree hot fryer oil into the sink and may end up melting the pipes?

Hey they used three sanitary tees to connect to the drain from the sinks, shouldn't that be three WYEs + a 1/4 bend?

one reason they give for not allowing PVC on commercial applications is that in a fire it will give off toxic fumes.

One inch separation between the top of the receptor and the bottom of the pipe would be an air gap, but that is not what is seen in the photo.

So I guess this is where the left over cuban coffee goes.

Now, why can't we do that with residential lavs? You just pipe it all the way to the toilet, and when not using the toilet, the pipe sits right over the bowl and dumps in there...

If you need to use the toilet, then the piping has a "swinging" joint that allows you to swing the pipe to one side, out of the way so you can use it, when done, swing it back.

quote; If you need to use the toilet, then the piping has a "swinging" joint that allows you to swing the pipe to one side, out of the way so you can use it, when done, swing it back

You realize that a hundred do it yourselfers just said, "What a great idea. I will have to try that for my next sink drain."

Hot water from the lavatory might crack the toilet bowl.