Plumbing – Can you have a 90 degree elbow going upward on drain line

drainplumbing

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.

enter image description here

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.

Best Answer

No, you should not do that. As mentioned in a comment, the drain is going to fill up with gunk and clog. Depending on use, you'll find that you have to snake this line quite often.

While traps do hold water, they are limited in the depth of water they can hold. Traps are also designed in such a way, that normal use stirs up any "sediment" and helps flush it away (self cleaning).

Uniform Plumbing Code

Chapter 10 Traps and Intercepters

1003.0 Traps - Described

1003.1 General Requirements. Each trap, except for traps within an interceptor or similar device shall be self-cleaning. Traps for bathtubs, showers, lavatories, sinks, laundry tubs, floor drains, urinals, drinking fountains, dental units, and similar fixtures shall be of standard design, weight and shall be of ABS, cast brass, cast iron, lead, PP, PVC, or other approved material.

I'm not sure how far away the vent is for this fixture. If that's 2" pipe, it has to be within 8' of the trap weir. If it's 1½" pipe, the vent has to be within 6' of the trap weir.

Related Topic