PVC to ABS Recommendations

Question

Under my kitchen sink is an ABS pipe going into the drain.

I need to shorten it, because the disposer is moving to the right side of the sink, and this pipe with Y-connector will be in the way. (the edict to move the disposer came from t'wife, so as long as I'm not against code, it has to happen)

What is the best way to attach the ABS to PVC to stay within plumbing code? I'm hearing comments about transition glue not being the best, and that I need a mechanical connection. I just want to do it the correct way.

Answer 1

I recently did something similar in my house. There was a transition from ABS to PVC already in place, and it was simply made using what I assume was regular PVC cement/glue. It held fine, the only reason I had to remove it was because I needed to move the pipes out of the way for something else.

I ended up using a coupling for the purpose with pipe clamps to make the new connection, as I felt better about it, and that is what code requires here (Minnesota):

705.11.3: Plastic Pipe to Other Materials

Where connecting plastic pipe to other types of plastic or other types of piping material; approved listed adapter or transition fittings and listed for the specific transition intended shall be used.

Watch out, as the ones home improvement stores carry (the all rubber ones) aren't usually technically approved for this, either. There is a specific listing they need to carry (UPC approval).

I've heard lots of people say it doesn't really matter in the end, glued connections will work fine, since these are non-pressurized systems. So if you want to strictly follow code, your answer is above.

Answer 2

It appears in the photo that the pipe stub coming out of the wall has some extra length that could be removed, a new "Y" installed which would give you the needed space.

It's a little difficult to judge the length but it appears there is a good 2" there.