Moving Kitchen Sink Drain Lower, can I swap with the stand tube??

[balizadeh]

Good day!

Looking for some help. I honestly have tried to have plumbers come out and do this but no luck where I live.

I am doing a kitchen remodel and the new sink sits 3 inches lower. The current drain disposal height is just at the drain wall level so it needs to be lowered.

I figure these are my options:
-Switch the stand tube and the drain? (This will lower the drain 4+ inches and have least amount of work question is if this is okay to have the vent and stuff above the drain instead of below wherever they meet up at?
-Use only the current stand tube and put a splitter that one end goes to stand tube and other goes to drain?
-Tear some of the wall up to find where these pipes meet the vertical tube and then add a split for a new drain or stand pipe?

 

[frodo]

what is draining into that stand pipe ?

 

[balizadeh]

Dishwasher drain (only when installed) and a RO filter waste.

The house location is an island so I would guess that stand tube was installed for a reason such as a vent.

Thanks!

 

[frodo]

abandon the top pipe. remove ptrap and install a plug/ screw cap

on the bottom pipe. remove the ptrap. install a 1 1/2 trap adaptor

install a a slip joint ptrap in the adapter.

directly on top of the trap. install 2 1 1/2'' wye branch tail pieces . you will have to cut them to fit

hook ro and dishwasher to theses y branch tail piece