[Brett-JDX748]

This is more of a question of how to do this and be code legal. Looking at the photo below, can I simply run a wye off the main drain line for the utility sink? Does the sink need it's own vent line?

Does that look right?

 

[coldwater]

Yup. Just make sure you keep the P trap. Because of where the line is, you should be fine as far as venting goes.

 

[Cat385B]

Yep, you can cut in a 4x4x2 wye right there, and reduce down as necessary over to the sink. Of course, they do make 2" p-traps, which are highly unlikely to clog. Whereas 1 1/2" traps on utility sinks often get some real crud run through them.

No vent needed, not far enough of a horizontal distance to warrant it.

If you use a swept tee instead of a wye, make sure to orientate it correctly. Not upside down, like the one on the next pipe over.

 

[Yamaguy]

Plumbing codes greatly vary from state to state, because in Illinois doing it that way would be against code. A single wet vent is ok, but once the second waste branch ties into the stack, you can no longer wet vent at the lower point. You can still tie into the stack, but you need to lay a tee on it's back and tie the vent into a vent 6" above the spill line of the sink (42" is used as a standard height). That other stack with the cleanout plug almost looks like a vent stack, is there a floor drain near by?

 

[LLigetfa]

The next pipe over is probably a vent.

 

[Yamaguy]

Nevermind I see that other stack is a Radon vent. How about some more pics? You can PM me if you like.

 

[Brett-JDX748]

Yep the next section over is a Radon evac system.

I don't have any other photos at the moment. This is at my Mother's place I will try to get some more photos when I take a trip up. This is in PA, I didn't look up the code to see if it needed a standalone vent, seems silly to me. If the idea is to stop Methane, isn't that part of the water trap's purpose?

 

[LLigetfa]

The purpose of a vent is so that the inertia of the water going down the drain doesn't suck the trap dry. Without enough water in the trap, sewer gasses can enter the home.

 

[Brett-JDX748]

The purpose of a vent is so that the inertia of the water going down the drain doesn't suck the trap dry. Without enough water in the trap, sewer gasses can enter the home.

That makes sense! No one gives plumbers enough credit, they **** near need a PHD in fluid dynamics