Automatic sprinklers are a part fire extinguishing systems. Usually part of a fire protection system based on a water reservoir for the supply system and a network of pipes which are terminal elements. They usually are activated by detecting the effects of a fire since the temperature rise associated with fire, or smoke is generated by combustion (fire sprinkler hydraulic calculations).

In 1902 Frederick Grinnell patented the design Grinel alarm check valve. Water system Grinnell. A - short tube diameter of half an inch, screwed into a water pipe and closes flat bottom valve b; valve lever is held and backup c d. Backup d attached to the copper arc e apparatus with a weak solder which melts at a temperature of 73 degrees C.

It consists of a thermo-sensitive element that is designed to destroy at predetermined temperatures, automatically causing the release of plug and the outlet of a water spray, which should extinguish the flame right in area where it has started. This device can be of two types: side of a disassembled sprayer without bulb or fuse Vista.

Fuse trip. The plug is held in position by a mechanism formed by two metal plates joined with a weld, with a melting point of carefully calibrated. In a blaze, the heat generated softens the solder, causing the water pressure acting on the cap and then disarm the system to skip the plug, allowing the escape of liquid. The water goes through the hole and strikes against a sheet, designed to distribute the jet way to rain (deflector). Each spray has its own fuse, so that only those sprinklers that are in zone of influence of trigger.

Therefore, in case of fire, after the destruction of temperature sensor, the lid remains tightly spray glued to the hull and the water from the system is not received. Such cases were reported in the fire at many places in USA. After that, the producers was conducted large-scale action to recall and replace all sprinklers with rubber sealing rings. In some countries the use of sprinklers with a rubber seal is prohibited.

According to statistics in case of activated fire sprinkler-systems 40% of the time the fire was extinguished by sprinklers, 80% of flames is extinguished when triggered no more than 10 sprinklers. On this basis, taking into account the area, protected by a single sprinkler (12 square meters is determined by the area, which is needed to irrigate the maximum flow of water sprinkler-system. For the first group space area is 120 square meters.

In protected space stretching combustible cord, which when blown open locks that hold the valve, the valve is released and the water flowed to a sprinkler. The device consisted of a cylindrical sealed tanks of about 95 tys.litrov system and 10-inch (250 mm) of the distribution of the aqueduct, covering all parts of the theater. Series of pipes of smaller diameter departed from the distribution pipes and were imbued with a number of half an inch (13 mm) holes through which poured water in case of fire. But the system was not automatic.

Another advantage of such a system is that the shot can be caused by smoke detection or detection of air ionization, since there are smoke detectors these extremes, while the temperature sensing function of temperature only. Its disadvantage is that, of course, is a more expensive installation.