Swapping kitchen drains?

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DanDz

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Hi all, new to this forum.
I am planning to replace an existing double sink with a new deeper double one.
I currently have the garbage disposal running over to the second drain and then to the P trap.
There is also an open pipe with a trap running under my counter top that has the dishwasher drain run into it, that drain is lower then the sink drain.
Since I only have one drain pipe coming down into the basement, I assume these 2 are running into a single pipe behind the wall.
With the new deeper sink can I swap the dishwasher drain with the sink drain, since the dishwasher drain is lower?
If yes, suggestions on how to connect the new sink drain since I will have to cut the existing elbow at the back of the cabinet to install the new cabinet?
I would then reinstall the elbow trap on the upper connection for the dishwasher drain. Does that one need to be glued vs. screwed?
Thanks in advance for your response.
Dan
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Reach4

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Since I only have one drain pipe coming down into the basement, I assume these 2 are running into a single pipe behind the wall.
With the new deeper sink can I swap the dishwasher drain with the sink drain, since the dishwasher drain is lower?
Disposals have a knock-out that lets you drain the dishwasher into the disposal.

You should run the dishwasher drainage through an air gap, and you should have the new sink have a hole for that air gap.

You would run the dishwasher drainage to one of your pipes, and cap the other.
 

DanDz

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Thanks!
Doing some research, I found that Colorado allows for 2 options;
1. an air gap above the counter top or
2. separately trapped with the airgap located on the stand pipe.

Not wanting another hole in the counter top I would prefer to stay with what I have which seems to be within code, though it does appear I need to add a wye at the top.

In a previous house, the dishwasher was drained into the garbage disposal. The draw back (in my opinion) was it seemed noisier when it drained since it's open to the sink vs. in a pipe in a cabinet behind the sink


My original question still stands though; can I swap position of the drains?
Is there any reason the sink drain needs to be above the dishwasher drain?

"STATE OF COLORADO EXAMINING BOARD OF PLUMBERS RULES AND REGULATIONS 3 CCR 720-1 SEPTEMBER 1, 2011 P6.00 DISHWASHER DRAIN DETAIL - IPC Section 802.1.6 Addition of a New Section 802.1.6 No domestic dishwashing machine shall be directly connected to a drainage system or food waste disposer without the use of an approved dishwasher airgap fitting on the discharge side of the dishwashing machine. Listed airgaps shall be installed with the flood level (FL) marking at or above the flood level of the sink or drainboard, whichever is higher, or separately trapped with the airgap located on the stand pipe."



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DanDz

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Thanks Wayne.
I read through the links and still think I'm good - after adding a wye with the min 3-inch air gap.
From what I read and see in the illustration for 802.1.8, the 3 inch air gap is created using the wye as shown in the illustration in the box.
In the illustration below I do not see an above counter air gap device.

However, every picture I see has the sink drain above the dishwasher standpipe, is that a requirement or just an example?


"Domestic dishwashing machines may be connected to a separately trapped stand pipe provided with an air break (with drain hose secured to the underside of the counter top) or air gap as shown in the illustration below."

Thanks, Dan.
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wwhitney

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409.4 says that you can connect the dishwasher to the garbage disposer inlet, and that instead of an above counter air gap, it's enough to do a high loop and secure the dishwasher to the underside of the counter. So that, along with Reach4's suggestion of using the lower wall entry and capping the upper wall entry, would be simplest.

If things were ever to back up into the sink, with a high loop it could back into the dishwasher if the level in the sink reaches that high point of the loop on the underside of the counter, as I understand it. So that's not quite as safe as an above counter air gap or a standpipe under the sink, but the idea is that you'd see it in the sink and have some warning before it got that high.

Cheers, Wayne
 

DanDz

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Wayne,
I agree with all.
From what I can see, the side port of the Wye would drain out (into the cabinet) before it reached the dishwasher hose. I think that is why they specify the gap between the side port and top of the wye of 3 inches (or 1 inch, hard to read).
Thanks, Dan.
 

Jeff H Young

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Dandz I dont think you are prohibited from putting the D/W standpipe on upper santee. Also we dont use the standpipe metod here. but they been doing that for decades other places. Many Many Californians hate the airgap showing and illegaly connect to the disposal directly.
If you think the stand pipe is quieter go for it ! I see no reason not to if you like that. Im not crazy about an open pipe inside my cabinet it could spill over
 
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