People are always asking what type of duct pipe can be used to vent a dryer in a 2x4 wall.
We have the answer from our resident expert. You can use a standard 4" snap lock. It just gets compressed in a 2X4 wall (3.5" deep). The only issue is, code will disallow dryer ducting in 2X4 walls in the future. It will need to be 2X6 or 2X4 with a furring strip.
Remember that if you need a 90 degree turn with no run-length penalty, use the Dryer-Ell.