An automatic sprinkler is a system used to automatically extinguish a fire without manual intervention. These systems consist of water-filled piping connected to sprinkler heads, which release water when they are exposed to high temperatures. Automatic sprinkler heads may contain fluid-filled bulbs or metal links that burst or melt under high levels of heat. Once the bulb bursts on the link melts, the sprinkler valves release water to fight the fire. Because these systems operate due to heat, only heads near the fire are activated, not the entire system.
Automatic sprinkler systems are available in a number of different forms to work in various applications. The most common is a wet system, which includes pipes that are always loaded with water. Once the sprinkler valve is activated, water is released immediately. In a dry system, the pipes are kept empty to prevent freezing. Once a head is activated, the water must travel through the pipes until it reaches the location of the fire, which could result in costly delays.
Pre-action systems are another popular variety, and are often found in museums, art galleries and computer rooms. These systems are automatic, but require two signals before they begin to operate. Heat exposure will activate the valve, but water is not released until the system receives a second signal from a smoke detector or other monitoring component. Some automatic sprinkler systems are filled with foam or dry chemicals instead of water, which can help to minimize damage to sensitive property, and may be more effective at fighting chemical or grease fires.
There are a number of benefits associated with automatic sprinkler systems. They offer quick action during a fire, and do not require personnel to stay behind and activate the system. Like all sprinkler systems, these units help to minimize property damage, and may give occupants more time to safely exit the building. Many insurance companies offer discounted premiums to organizations with properly installed sprinkler systems.
The design and installation requirements for fire sprinklers is set by local building codes. These codes are often influenced by standards developed by the National Fire Protection Association (NFPA). The NFPA is an international organization that develops standards for testing and installing fire protection systems. NFPA has created standards aimed at both commercial and residential sprinkler systems. Since the start of the 21st century, many local governments have added residential sprinkler requirements to the existing commercial requirements already in the building codes.