View Full Version : Kitchen Sink... No Vent? Plus Moving Plumbing

05-26-2011, 09:41 AM
Hi Everyone,

The below pictures are of my (old) kitchen sink setup. To me there appears to be no vent. The picture from below the house seems to show the same thing because the 3" pipe that continues to the left connects to the plumbing that leads to the sewer...

http://farm4.static.flickr.com/3083/5762324928_4deb020940_z.jpg (http://www.flickr.com/photos/61765654@N05/5762324928/)

http://farm6.static.flickr.com/5182/5761780797_4b1980546f_z.jpg (http://www.flickr.com/photos/61765654@N05/5761780797/)

From the inside of the kitchen picture I plan on moving the sink to the right and using it as a corner sink.

I want to me sure I do everything right and it is correctly vented. What is the best way to do this?

Should I just copy the ABS setup that I have and connect it to the main pipe under the house?



05-26-2011, 09:57 AM
I haven't seen a sink plumbed that way before.

If you have a vent somewhere between the kitchen sink and the other plumbing, I would think you would be okay.
In a sense, using the oversized pipe is like having a loop vent without the loop.
I don't know how an inspector would view it there.
I personally wouldn't install one that way unless I had talked to a local inspector first.
And if I did, I would want a vent included like the picture below has.

An island vent looks more like this

The santee on the vent below the floor should have been a combo.

05-26-2011, 10:19 AM

My kitchen is hooked up just like the original posters.

I am on my own septic system, and I have the kitchen sink going into a grease trap.

Should I have a vent also ? I guess we have no codes here in the sticks.

You Expert Plumbers have a lot to keep in your brain, and I am out of memory.

Enjoy your Day, Take time to play.


05-26-2011, 01:08 PM
I think with the 3" line, and the fact that you must have already had an inspection, that it will be fine.
The oversized 3" line allows for air over the flowline.
In Japan, that's how they do a lot of the plumbing. Oversized trunk lines to provide venting.