Two drain lines into stack from opposing directions

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We’re remodeling our kitchen and it involves moving the kitchen sink. The drain line used to be on the same side of the drain stack as the bathroom sink. The new location puts it on the other side of the stack. Can I use this fitting: 3x3x1.5x1.5? Is a double wye more appropriate?

Both drain lines will be vented individually and I am thinking that same fitting (flipped upside down) would be needed to tie the vents into the stack as well. Any guidance would be much appreciated.

follow up question: my research pointed me to this Mission coupler to connect my new PVC stack to the existing copper one. Lowe’s only had the “flexible coupling” that was approved for copper. The shielded one doesn’t say it’s for copper pipe. Any advice?

A couple pictures of the current stack for reference. These were taken from inside the bathroom. The current kitchen sink drain goes through the wall. The new kitchen drain will come from the left behind the tub. (there are all sorts of issues with the existing plumbing, drain slopes the wrong way, current sanitary tee for vent is backwards, tee used to combine drain lines instead of wye, etc).


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