Heat from a fire causes the heat-actuating plug in the sprinkler to drop from the frame.
Pressurized air contained in the piping begins to flow through the open sprinkler.
After a slight drop in air pressure, the quick-opening device activates to accelerate the removal of air from the piping.
Once the air pressure is reduced sufficiently, the dry-pipe valve trips open.
Water enters the intermediate chamber of the dry-pipe valve and begins the flow of water through alarm-signaling equipment.
Water flows through the entire piping system and is discharged through the open sprinkler.