The above concept should be clear enough on how this system works. To start with, this system is similar to the wet sprinkler system apart from the segregation of water and pressurized air.
In an apartment, you would normally sprinkler heads aligned per specifications to offer full coverage. Once fire emerges, the liquid that keeps the sprinkler heads closed will expand and then break the glass. Consequently, the head will open thus letting the pressurized air or nitrogen exit. This, in turn, decreases the pressure in the pipe.
What happens next? The dry pipe valve is burst open by the differential pressure because air has been discharged. Water will flow at high pressure to the open sprinkler heads and then get discharged to the adjacent fire break out.
Like in the wet sprinkler system, only the sprinkler head in proximity to the fire gets actuated while others remain closed. If the fire is hot enough in a small room, other sprinkler heads may be burst open too due to the expanding liquid.
Note that the water will get discharged continually unless deactivated manually at the valve if the fire has been extinguished. The purpose of the sprinkler is to suppress the fire until relevant firefighters arrive at the scene. In a process of discharging water, the alarm at the sprinkler riser will be triggered to alert firefighters and occupants of the building about fire.
New York Engineers always ensures that the sprinkler riser is functioning optimally with all the valves, alarms and the drains checked. The efficiency of this system lies in its design, installation, and maintenance.