I'm running a drain for a utility sink off of a stack in my basement. I wanted to know if it's ok to have a 90 degree elbow going up then out to the utility sink since when the water drains it's going to have to go back up the 90 degree elbow to the main drain. I've attached a picture.
The drain then runs to the left to a secondary drain line that runs vertical in my basement. Just not sure if you are allowed to drop a 90 degree angle like this since the water would have to go up when I use the utility sink.