The evacuation checklist on the 737NG:
Parking brake …SET
Speedbrake lever … DOWN
FLAP lever ….40
Pressurization mode selector… MAN
Outflow valve switch… OPEN
Hold until the outflow valve is fully open.
If time allows, verify that the flaps are 40 before the engine start levers are moved to CUTOFF.
Engine start levers (both) … CUTOFF
To be continued….
The reason for the flaps is set to 40 is to assist the evacuation from the overwing exit. The passengers can slide on the flaps.
Walder