I want to thank everyone in advance for their insights. Here is the situation. I would like to renovate the kitchen of my two family home built in the 1920s to include, among other things, a dishwasher. The kitchens are stacked on top of one another and the sinks are served by the same drain and vent system. (The main waste stack is not involved here and is located in another part of the house.)
Currently, I cannot install the dishwasher because of some clearance issues caused by the drain which is connected to the drain pipe on the right as depicted in the attached photo. I would like to move the sink drain to the left pipe because it is not located behind the area proposed for the new dishwasher. In short, both drain pipes will remain, I will just be tapping into a different one. Can this be done — is there any problem with having two sinks on top of one another?