ASP Study Guide · Fire Prevention
Study how automatic sprinkler, water-based, and special-hazard systems detect, control, and suppress fires in workplace occupancies.
Core standard
NFPA 13
Primary system
Sprinklers
Topics covered
4 Sections
Automatic suppression systems provide early fire control when occupants are not able to respond safely or quickly enough. System selection depends on the occupancy, the hazard, water supply, and the consequences of unwanted discharge.
For the ASP exam, distinguish the operating principles, applications, and limitations of water-based and special-hazard suppression systems.
Most sprinkler systems activate at individual heads exposed to sufficient heat; they do not all discharge at once.
A sprinkler's thermal element, such as a fusible link or glass bulb, operates when it reaches its rated temperature. Heat from the fire, not smoke, normally activates the sprinkler head.
In standard wet- and dry-pipe systems, only sprinklers exposed to adequate heat operate. This concentrates water at the fire area and limits unnecessary water damage.
The system arrangement determines where it can be used and how quickly water reaches an operating head.
Wet-pipe systems keep pressurized water in the piping at all times. They provide rapid, reliable response and are the most common sprinkler arrangement, but they are not suitable where piping can freeze.
Dry-pipe systems contain pressurized air or nitrogen in the piping until a sprinkler operates. They protect spaces exposed to freezing temperatures but introduce a water-delivery delay.
Preaction systems use a separate detection event before admitting water into the sprinkler piping. They are used where accidental water discharge is a major concern, such as data centers, museums, or archives.
Deluge systems use open nozzles or sprinkler heads and release water over an entire hazard area after a detection system operates. They are used for high-hazard occupancies requiring rapid, broad application.
Some hazards require agents other than water because of sensitive equipment, fuel characteristics, or the need to protect a specific enclosure.
Carbon dioxide suppresses fires by reducing oxygen concentration. It can be effective in enclosed hazards but presents a serious asphyxiation risk, so safeguards, alarms, evacuation procedures, and occupant protection are essential.
Clean agents suppress fire without leaving residue, making them suitable for sensitive equipment and occupied enclosures when designed for the application. Review the agent's safety limits and environmental requirements.
Foam forms a blanket that helps suppress flammable-liquid vapors and separates fuel from oxygen. It is commonly used for fuel-storage, loading, and other Class B liquid hazards.
A suppression system protects only when it is designed for the hazard and kept in service.
NFPA 13 governs the installation of sprinkler systems. Occupancy and commodity hazards influence the required density, area of operation, sprinkler arrangement, and water supply.
Inspect, test, and maintain valves, alarms, water supplies, supervisory devices, and sprinkler components according to the applicable standard and site program. Document deficiencies and correct them promptly.
When a suppression system is out of service, use a formal impairment process. Notify responsible parties, control ignition sources and combustibles, provide compensatory measures such as fire watch, and restore protection as soon as possible.
Check your knowledge
Use the Fire Suppression Systems Quiz to reinforce sprinkler types, special-hazard agents, and system impairment controls.