Fire sprinkler systems were developed to protect buildings from
fire by producing a discharge of water. The sprinkler piping is
usually run near the ceiling directing the water down on the flames.
The first automatic sprinkler system was created in England in
the early 1800s. It was made up of a pipe with several valves held
closed by counterweights attached by string. When flames burned
through the string the counterweight dropped to the floor, which
opened the valve that released the water and extinguished the fire.
Manually operated systems were developed around the turn of the
nineteenth century as well. Manual systems consisted of a number
of perforated pipes fed by a main riser, which was activated from
an adjacent area. Manual systems were effective at dousing fires.
However, water damage to the building and the contents not effected
by the flames were often more costly than the fire damage.
The Parmelee sprinkler head developed in the United States, in
the 1870s, provided a way to control which heads discharged water.
The newly designed head incorporated a heat-sensing device that
only opened the valve when a predetermined temperature was reached.
The heat of the flames activated specific heads, leaving areas unaffected
by the fire dry. Modern sprinkler heads use a bulb containing chemicals
or a fusible link, that breaks at around 160° F, opening the
valve, releasing the water.
From the days when fire sprinklers randomly sprayed water to systems
that can regulate the discharge covering an area of a few square
feet, automatic fire sprinkler systems protect property saving millions
of dollars annually. Most importantly they save lives!