Drain crawl space tie-in question

[MTKliving]

DIYer... Wanted to add a wet bar drain for small sink. Will be using in-cabinet AAV (only one in house and code compliant for raleigh, nc). Not sure best spot to tie in to branch drain pipe in crawl space. There is a 3" vertical drain pipe entering crawl space nearby with ~45 degree bend before tie-in to 4" horizontal. Should I tie in to this 3" branch drain within the 45 degree section or to the 4" horizontal (harder to move). It would be easier for me to tie-in to the 3" 45 degree branch. Wye or sanitary tee? Is exact angle measurement required? Any issues with setup in pic? Thanks so much!!

 

[Reach4]

I am not a plumber. There may well be something better. One rule to watch for is whenever you transition from vertical to horizontal, you need a long sweep or combo.

1. 3" x 3" x 2" PVC DWV Wye (45 degrees) at the arrow.

2. 45 degree 2 inch DWV elbow somewhere to the right of that, to make the angles come out right.
3. 45 and wye combination where you transition from vertical coming down to horizontal. I am not sure that a wye would not work here

4. SanTee above the floor under the AAV and over the pipe going down.

 

[Sponsor]

 

[Terry]

On the 45 like that, it's considered vertical. You can use a santee there or a wye (wye combo) fitting. Lot's of options on that location.
Where it goes up to the sink, a combo or wye fitting.