Overview Of Fire Sprinkler Hydraulic Calculations

By Young Lindsay


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).

A fire sprinkler is a device for extinguishing fires. Consists of an armature, with a pipe connected to a water pipe pressure. The pipe is closed with a cover subject by a glass capsule filled with a liquid whose boiling point is at a certain temperature (temperature trigger) which is subject against a disperser. When a fire occurs, the liquid boils and the steam breaks the capsule; the lid bounces, exits the water and crashes into the disperser sprinkling the burned area.

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.

The spray outlet is somewhat less sharp slope of the teeth to its plane and a little more in diameter; glass valve polished, chamfered and sprinklers have higher gate outlet. For some time, some of the sprinklers manufacturers to reduce the cost structure used as a sealant rubber gasket. Thus it was not taken into account that over time the elastic properties of rubber deteriorates, and can result in loss of containment. But the worst thing that can happen to the adhesion of rubber sealing surfaces.

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.

The response time of these systems shall not exceed 300 seconds for low-temperature sprinklers (57 and 68 degrees C) and 600 seconds for the highest-temperature sprinklers. In 1806, an automatic fire extinguishing installation was patented by Englishman John Carey. He proposed to build in the protected area network of pipelines from the water head tank, and on the network to install sprinklers with small holes.

Another way to activate a sprinkler is associated with flame detector which opens the closed spray, which in this case is a solenoid valve (solenoid valve) when a flame occurs in area protected by the sprinkler. The advantage of this system is that, once the blaze is out, the water outlet is cut and, if reignite, reopens. With the system of sensitive element, it would take someone off the water supply or water damage could exceed those caused by the inferno.

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.




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