Simple one - Banded Couplers inside Wall ?

I searched around, but didn't get a direct answer in the forums...

Is it code compliant to put a banded coupler inside a wall without an inspection panel? I need to increase a drain from 1.5" to 2" for a washing machine. My plan was to insert PVC into a 3" copper main stack. I'm putting a washing machine where a lav previously occupied.

Is the correct fitting a 3x3x2 combo or san-t ?

isn't the end of the world if i cann't, just trying to save opening a wall for a new vent..

thanks! as always....

hj caught this, I didn't, this post has now been changed to read
No hub couplings dont work with copper, they are for no-hub cast iron.
They do make couplings that transistion between copper pipe and plastic in the Proflex line.

Thanks Terry.

coupling

No-Hub couplings WILL NOT work on a copper pipe. You need material specific transition couplings. Assuming this is a vertical pipe you need a sanitary tee, and unless the pipe itself is a vent, the washer would need its own vent.

hj caught this, I didn't, this post has now been changed to read
No hub couplings dont work with copper, they are for no-hub cast iron.
They do make couplings that transistion between copper pipe and plastic in the Proflex line.
They must read on the label, that they "are" for copper. If they don't, they don't work.