Vent tee in kitchen waste line

Anyone have a blurb about using a vent tee in place of a sani tee?

That looks wrong.
May be the picture but I see no 1/4 inch per foot slope and also the drain on the left with the dishwasher waste tee should simply go over to the right hand drain up high and connect there and drop down to the horizontal run with a wye connection.
That would be much better than a straight out tee connection.

Sorry but this is just a quick sketch example.

Yea your pic is a better way for sure. I was curious about the straight tee connection, where a sani tee is more appropriate since it has directional flow (would help prevent the right sink from backing up into the left).

Tee connection is OK at top going horizontal to vertical because gravity makes it drop down but it should be angled when going from vertical to horizontal.
Hope that makes sense.

This ppt rocks if you download it.Took me some time to find it online for yo to download.

I would like too see a plumber comment but I’ll weigh in any way.
If my understanding of the plumbing code is correct because the change in direction of flow is vertical too horizontal the fitting is required to be a Wye. A sanitary tee can only be used when the flow direction is horizontal to vertical with the sink located above the fitting the flow direction is horizontal to vertical and because the change of direction is greater than 45 degrees a clean out would also be required. But to address your original point you are correct a straight tee is not permitted for the application identified in your photograph

Mark is correct - that is not an appropriate location for a sanitary-tee. A wye is required.

Simply report that improper fitting are being used in the drain line and corrections should be made by a qualified plumber.

Are you stating I am not correct?,because to me it appears Mark said the same thing as myself except I explained the actual reasoning not being a code inspector and all.:slight_smile:

Thanks Mark. Thats what I was thinking. A vent tee is not appropriate for this application.

Did you download that ppt Darin?

Getting it now Bob.

Great stuff Bob. Thanks for sharing.

Slide 66:

706.4 Vertical drainage lines, connecting with horizontal drainage lines shall enter through forty-five (45) degree wye branches, combination wye and one-eighth 1/8 bend branches, or other approved fittings of equivalent sweep. Sixty (60) degree branches or offsets may be used only when installed in a true vertical position.

So the lack of a sweep in a typical vent connection is where the “plumber” went wrong.

What you said about the water flow and I think also it has to do with being able to rod out.
Wish these codes would always explain exact reasoning as they always leave us to guess many times.

Not at all Bob, you are correct, however, Mark stated that the sanitary-tee is not allowed for this application, which is what I was referring to as being “correct.”

Code inspector or not, a sanitary-tee is only allowed to be used in the vertical position in a “horizontal-to-vertical” application. A sanitary-tee is not allowed to lay on its “back.”

OK gottya.Clarified.

Great PP…240 slides…thanks Bob.

Hope this helps.

Sanitary tee.jpg

Bob, thanks for the PP I found it to be educational. A green square and karma for you!!