The concept of automatic fire sprinkler systems dates back to the 1800s, most notably to English inventor John Carey. He developed a heat-operated system that distributed water through perforated pipes to extinguish fire. In 1864, Major Stewart Harrison of London’s 1st Engineer Volunteers improved on Carey’s idea by introducing the automatic sprinkler. Meanwhile, in the United States, Henry S. Parmelee harnessed the technology by creating the first commercially successful closed sprinkler system.
The central idea of the automatic fire sprinkler system is to have a steady supply of fire extinguishing material (usually water, but in some cases specially formulated foam) ready to burst into action when the need arises and to automatically turn off when the need has ended. Automatic fire sprinkler systems are of two types: residential and commercial. The modes of delivering the extinguishing material are the wet pipe, dry pipe, pre-action and deluge.
Among the four types, the wet pipe arrangement is simplest, least expensive and most common. Wet pipe is the choice for homes, stores, warehouses, dormitories and nursing homes.
The dry pipe arrangement is the best choice in environments subject to freezing temperatures. Examples of use include loading docks, unheated warehouses and attics.
The pre-action arrangement typically does not activate until fire is confirmed by detection equipment such as heat and smoke detectors. Use is appropriate in computer rooms, art galleries and other places containing high-value assets.
In the deluge arrangement, as the name suggests, the extinguishing material is delivered by all sprinklers simultaneously with maximum volume. Deluge is preferred in factories, petrochemical plants and aircraft hangars.
Source: American Fire Sprinkler Association at www.afsascholarship.org.