| Dictionary, Encyclopedia and Thesaurus - The Free Dictionary 3,900,595,694 visitors served. |
Dictionary/ thesaurus | Medical dictionary | Legal dictionary | Financial dictionary | Acronyms | Idioms | Encyclopedia | Wikipedia encyclopedia | ? |
Fire-Fighting System, Automatic |
0.01 sec. |
|
|
Fire-Fighting System, Automatic
a system of equipment used to prevent, extinguish, localize, or block fires in enclosed spaces. Automatic fire-fighting systems are installed in buildings and rooms where the fire hazard is comparatively high. A distinction is made between systems that are actuated automatically and operate according to a predetermined program and those that are actuated by an operator; the former are called automatic fire protection systems, the latter fire protection units. An automatic fire-fighting system includes a sensor capable of detecting combustion, alarm signaling devices, fire-extinguishing equipment, starting and stopping devices, and feeders for the fire-extinguishing substance; in some cases, it includes control equipment for the production process being protected. Atomizers, foam generators, and pipe nozzles form and direct the stream of the fire-extinguishing substance, which may be a liquid, foam, powder, or gas. Fire-extinguishing substances are fed into the system from a centralized supply, such as a water supply, or from self-contained or combined feeders. The most widely used systems employ water (sprinkler and drencher systems), carbon dioxide, aerosols, or powders. A sprinkler system consists of a grid of pipelines located on the ceiling of the room, with sprinkler heads attached to the pipes by threaded connections. The opening of a sprinkler is kept closed by a disk held in a closed position by a thermal lock. If the room temperature rises to a specified point, the lock is destroyed and the disk opens, admitting water to the room. Drencher systems, which use nozzles without thermal locks, are actuated either by a sprinkler installed in a trigger air line or by a cable-type thermal lock. Automatic fire protection systems are classified according to the time elapsed between the start of the fire and the actuation of the system as ultrahigh-speed (to 0.1 sec), high-speed (to 3 sec), and standard (to 180 sec). The fire-extinguishing substance can be applied for periods ranging from 30 sec to 60 min. A. I. VESELOV Want to thank TFD for its existence? Tell a friend about us, add a link to this page, add the site to iGoogle, or visit the webmaster's page for free fun content. |
|
| Encyclopedia |
| Free Tools: |
For surfers:
Free toolbar & extensions |
Word of the Day |
Help
For webmasters: Free content | Linking | Lookup box | Double-click lookup |
|---|