Fire Protection Glossary
Fire Alarm System
Alarm System: Combination of initiating devices, control panels, and indicating appliances designed to notify the occupants of a building of intrusion, fire, flood, supervisory signals, etc.
Detector: A device with a sensor that responds to heat or smoke created by a fire.
Duct Detector: Fire alarms located in your HVAC ducts are designed to detect smoke moving through your building.
Fire Alarm System: A system that monitors and annunciates the status of the fire alarm or supervisory signal–initiating devices and initiates the appropriate response to those signals.
Fire Pump: Pump that increases the pressure of a water source when that source is not adequate for the system it is supplying. It is commonly found in buildings, such as high-rise or storage warehouses.
Fire Sprinkler Components
Alarm Valve: Permits water to flow into the sprinkler system.
Alarm Test Valve: Allows you to test your fire sprinkler system under shut-off conditions.
Escutcheon Plate: A small, round shield, often made of metal, around the fire sprinkler head.
Flow Switch: Monitors the flow of water through different sections of the pipe within the automatic fire sprinkler system. If the flow switches sense sufficient water flow, they trigger an alarm.
Pressure Gauge: used in dry-pipe sprinkler systems to measure pressure.
Pressure Switch: Enables the fire sprinkler system to alert the fire department that your fire sprinkler system is going off by watching for a fall in water pressure after the alarm valve.
Stop Valve: Stops water from flowing from the city water supply into the fire sprinkler system.
Types of Fire Sprinkler Systems
Antifreeze Sprinkler System: A wet pipe fire sprinkler system that incorporates a small amount of antifreeze in its pipes to prevent the water from freezing during cold weather.
Automatic Sprinkler System: specially designed to put out fires without setting off all the sprinklers in the building, keeping the fire and the damage it causes contained.
Deluge Fire Protection System: These systems have open nozzles and release water, which is often mixed with fire retardants via a valve triggered by smoke or heat. Typically used in highly hazardous environments.
Dry Pipe Fire Sprinkler System: An automatic fire sprinkler system that stores water in a central tank instead of the pipes. Slightly increasing the sprinkler response time is useful in areas where water stored in pipes can freeze.
Fire Sprinkler System: fire protection method consisting of pipes and sprinkler heads installed in a building to control and extinguish fires.
Hydraulically Designed System: Calculated sprinkler system where pipe sizes are selected based on pressure loss to prescribe water density in gallons/min/square feet.
Pre-action Fire Sprinkler Systems: Pre-action systems feature closed sprinkler heads that only open upon the detection of fire signals, thereby reducing the chances of accidental discharge. They are often used in sensitive areas such as data centers or libraries, offering extra protection against inadvertent activation.
Sprinkler Head: A sprayer that connects to a water pipe and is activated by a fusible link or heat-sensitive bulb, with a deflector that breaks up the water into fine droplets.
Sprinkler System: Grid of water pipes and sprinkler heads installed in a building to control and extinguish fires.
Wet Pipe Fire Sprinkler System: A standard fire sprinkler system with water stored directly in the pipes held back by the fire sprinkler heads until the fire starts.
Types of Hydrants
Wall Hydrant: A hydrant mounted on the outside wall of a building that is fed from interior piping and equipped with control valves located inside the building.
Wet Barrel Hydrant: Type of fire hydrant sometimes used where there is little to no danger of freezing weather.
Organizations, Terms & Institutions
Authority Having Jurisdiction (AHJ): Organization, office, or individual responsible for approving equipment, materials, installations, and procedures.
American National Standards Institute (ANSI): Organization charged with overseeing the development of standards for products, services, processes, systems, and personnel in the United States.
Underwriters Laboratories (UL): A certification authority for many appliances and systems associated with fire protection.
Waterflow Detector: A device that detects the flow of water in a deluge system.
Fire Behavior & Safety Terms
Discharge Pressure: refers to the level of water pressure on the fire pump discharge manifold at the point of gauge attachment.
Ionization Smoke Detection: This is based on the principle of using a small amount of radioactive material to ionize the air between two differentially charged electrodes, which helps to detect the presence of smoke particles.
Photoelectric Light-Scattering Smoke Detection: relies on the use of a light source and a photosensitive sensor, arranged in such a way that the rays from the light source do not normally fall onto the sensor. When smoke particles enter the light path, some of the light is scattered onto the sensor, which then processes the signal and conveys an alarm condition when it meets certain criteria.
Water Hammer: refers to the sudden surge in pressure that occurs when fast-moving water is abruptly blocked, resulting in a pressure that can be seven or more times greater than the static pressure.
Working Pressure: The maximum allowable pressure to which a sprinkler system, pipe, or hose can be safely applied.