How to install dishwasher drain to double sink?

**TCiura** · 09-18-2007, 01:57 PM

I am remodeling my kitchen and I am adding a dishwasher. Previously there was none. I know my local ACE hardware sell's a pvc branch with tail to attach dishwasher drain. My question is with a dual sink setup how do I attach the branch tailpiece and the horizontal pvc piece that connects both sinks? Does anyone have a diagram or website where I can see a diagram of the setup? Everything I find only has examples for a single sink setup.

Thanks for your help

**geniescience** · 09-18-2007, 02:13 PM

End outlet
with
dishwasher branch connection

Search on these terms.

Also:
Center outlet
CONTINUOUS WASTE
dishwasher Wye
dishwasher Tee

-david

**Livin4Real** · 09-18-2007, 08:53 PM

If there is enough pipe after the trap (between sink trap and floor of cabinet) in the vertical section would be a good place to put a wye for the dishwasher.
That's how I plan on running the one I'm about to install in our remodel.

**wyoplumb** · 09-18-2007, 10:13 PM

do not install after the trap. It is possible to get sewer gas through your line and into your dishwasher which in turn you will get the gas in your kitchen area. You need to put the branch wye in before the trap. you may need to lower your waste outlets coming off of your sink strainer baskets.

**Livin4Real** · 09-19-2007, 02:52 AM

I was assuming there would be a trap for the dishwasher as well. The one-piece p-traps.

hj · 09-19-2007, 05:34 AM

Connecting it directly to the drain system, with or without a trap, is usually illegal because contamination in the DW could occur very easily under the right conditions.

**geniescience** · 09-19-2007, 10:43 AM

you will see diagrams aplenty, Tciura, so you will know that your trap is the last thing in the series.

what have you found so far? What material is your "tubular" made of. Tubular is one more good word to use in key word searches.

Tubular is the pipe stuff that repairpeople, handymen and handywomen are allowed to change out, without being licensed as plumbers.

david

**Livin4Real** · 09-19-2007, 02:27 PM

OK, going to try and redeem myself now, lol.

**Terry** · 09-19-2007, 05:13 PM

This picture above is legal plumbing where they use the UPC plumbing code. Uniform Plumbing Code.

S-traps that go through the bottom of the cabinet like the drawings in the post above would not be legal in UPC country.

**GrumpyPlumber** · 09-19-2007, 05:51 PM

Originally Posted by Terry

S-traps that go through the bottom of the cabinet like the drawings in the post above would not be legal in UPC country.

I don't think they're legal anywhere.

**Livin4Real** · 09-19-2007, 09:59 PM

I give up, lol.That's bad when the manufacturer's drawings aren't right.

Now, after searching the archives here, the loop system was mentioned several times as being a good alternative but also not being code since alot of areas require the airgaps, some folks complaining about airgaps and water getting under them into the countertops. What's your opinions on the loop system? I also thought the new DW's have one-way check valves on the drain to keep bad stuff from getting in? I'm glad this thread came up cause I've learned alot.

**jadnashua** · 09-20-2007, 08:32 AM

First, check with the local code people...you may not have a choice. An air gap is a guaranteed way to install it safely. A high loop is a gamble...admittedly, a long-shot, but still a gamble on overall safety.

**sparky828** · 04-18-2008, 01:30 PM

Hello all. I apologize in advance for my lack of knowledge of the correct terms. I hope my descriptions will paint an accurate picture.

I'm struggling with this issue as well. At present, I have two sinks, no disposal and a dishwasher that was draining on the wrong side of the trap. Each sink has a horizontal pipe that runs to a central piece that then sends the water vertically down to the j-bend. I tried to put the piece with the branch between the joining piece that drain from the sinks and the j-bend, but even after sawing down the bottoms of both the fitting and the branch piece, they are a maddening 1/2" too long for the j-bend to meet the . Now I see why my father-in-law put it where he did when he installed the dishwasher

Is it possible/legal to put the piece with the dishwasher branch in a horizontal position in place of one of the horizontal pieces before the join?

Here's the old configuration for reference:

Thanks!

**krow** · 04-18-2008, 05:19 PM

Originally Posted by sparky828

Is it possible/legal to put the piece with the dishwasher branch in a horizontal position in place of one of the horizontal pieces before the join?

Yes it is legal, but you will have to use a Wye instead of a T

**sparky828** · 04-18-2008, 05:55 PM

Originally Posted by krow

Yes it is legal, but you will have to use a Wye instead of a T

Thanks much for your response, and this where I further confirm my ignorance. I'm guessing the difference between a Wye and a T hinges on the angle at which the stem comes off of the tube. If that's what it is, then I think it's a Wye I have (the perspective in the picture above is misleading).

This is the piece I'm thinking of using (already partly cut in my previous attempt to fit it vertical):

Wye? Wye not?