Sprinkler head

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A fire sprinkler head is the part of a fire sprinkler system that allows the extinguishing medium to discharge. A fire sprinkler system consists of a network of overhead pipes that release a fluid, foam or gas automatically through sprinkler heads when a predetermined temperature has been reached. Most sprinkler systems extinguish with water. They are called wet systems which use pipes filled with water.

Contents 1 History 2 US regulatory requirements 3 Operation 4 Types 5 Sources

[edit] History

In the 1870s, the Parmelee sprinkler head, was introduced in the United States. Heat from a fire opens the normally closed orifice releasing the water. Modern sprinkler head versions use a fusible link or a bulb containing chemicals, which breaks at about 160° F (70° C) to open the orifice.

[edit] US regulatory requirements

Sprinkler systems and sprinkler heads are regulated by the National Fire Protection Association (NFPA) 13. NFPA 13 requires a minimum water pressure of 7 psi at the sprinkler head.

[edit] Operation

Sprinkler head seals may be broken by melting (fusing) of metals with a low melting point (often bismuth alloys), or may be glass bulbs filled with fluid that expands and breaks when heated. An activated sprinkler head, generally discharges around 14 US gallons per minute (1 L/s).

[edit] Types

Sprinkler bulbs are colour-coded to indicate their operating temperature. Typical activation temperatures vary and correspond to the type of hazard the sprinkler system protects against. Life safety hazards, such as residential occupancies, use a lower (therefore quicker) activation temperature.

Modern sprinkler heads are designed to direct a spray downward. When one fire sprinkler head goes off to fight a fire, the entire sprinkler system does not activate unless the system is a special deluge system. Sprinklers heads react to temperatures in individual rooms.

[edit] Sources

• American Fire Sprinkler Association