I want to replace a double kitchen sink with a single sink model that is about 4" deeper. A disposal is currently installed and will be reinstalled in the single sink. I'm concerned that the new sink will lower the drain piping such that the p-trap will need to be lowered. I am unfamiliar with a way to lower the "outlet" (wall) end of a p-trap. The traps I see at hardware stores/home centers have a factory/molded coupling with an elbow at the outlet end. Is there any way to lower the p-trap assembly? Thanks in advance.

Mike

"Is there any way to lower the p-trap assembly?"
Yes there is Mike, but you're not going to like it. First unhook the supplies and drainage from the sink. Next remove the sink and cabinet and open up the wall all the way back to the vent stack. Next you will have to cut a piece out of the vent stack and lower the horizontal arm and stubout to the desired level. Now the wall will have to be patched and the cabinet reinstalled. You may now install the new sink and run the trap, drainage and supplies. I'll bet that single compartment sink doesn't look near as attractive now as it once did. Did I mention how difficult it will be to keep the kitchen vent stack from falling down after you make the cut? Especially in a two story house.
Good luck and let me know what you decide. Regards, Tom

Thank you for your quick and understandable reply. Wow! I think I'll remain within the spec from just below the disposal elbow to the top of the outlet pipe! Thanks for the help

Mike