Anyone see anything obviously wrong....and vent size question!

[J Blow]

Here's a layout I'm planning on using for a bar sink in a basement remodel. As you can see it's a 1.5" sink drain and that dumps directly into the main stack that first runs through a 2 x 2 x 1.5 fitting and then a medium 90 (I think). Or does the 90 need to be a long sweep?

Now the vent question...it eventually joins a 1.5" vent that comes from the shower and then to the 2" vent from the ceiling. Is it ok to go to 1.5? Would it be better if it stayed 2" and the 1.5 from the shower joined with a fitting like in the picture? Can I convert it to a 1.5 right out of the top of the fitting pictured above? Are there venting restrictions based on size combinations?

 

[Daniel Collick]

Yes, a long sweep would be the correct fitting underneath your 2"x 2"x 1-1/2" sanitary tee.
If reducing down to 1-1/2" out of the top of your "san-tee" helps you sneak by something else in the wall, then ok. You're not doing anything wrong. They actually make a 2"x 1-1/2"x 1-1/2" san-tee for future reference so you don't have to purchase the additional bushing.
When you tie the two vent lines together using a similar fitting the orientation of the fitting is reversed from the position in your picture. Now, if you're planning on connecting to the toilet vent, which should be 2", it's important to increase your 1-1/2" vent at the point where it connects to your 2" toilet vent.
Hope this helps, and sorry for the long read.

 

[Sponsor]

 

[hj]

Just get a tee with a 1 1/2" top opening, and a long radius 90.