AL Fire Sprinkler flashcards
AL Fire Sprinkler · Build recall with a focused review session.
32 cards. Read the term and the definition here. The deck at the top of this page is optional.
- Design density
- The amount of water in gallons per minute per square foot (gpm/ft²) that must be applied over the design area; it is determined by the occupancy hazard classification.
- Remote area
- The hydraulically most demanding area of sprinkler operation used for calculating water demand; its size depends on hazard and system type.
- Light hazard occupancy
- An occupancy where the amount of combustibles is low and fire severity is expected to be low, such as offices, churches, and schools; design density is typically 0.10 gpm/ft².
- Ordinary hazard Group 1
- An occupancy with moderate combustibles and stockpiles up to 8 ft high, such as parking garages and restaurants; design density is 0.15 gpm/ft² over 1,500 ft².
- Ordinary hazard Group 2
- An occupancy with moderate to high combustibles and stockpiles up to 12 ft high, such as mercantile and manufacturing; design density is 0.20 gpm/ft² over 1,500 ft².
- Extra hazard occupancy
- An occupancy with high combustibles, flammable liquids, or high-piled storage where fire severity is high; design densities start at 0.30 gpm/ft² and require larger remote areas.
- Sprinkler temperature rating
- The temperature at which a sprinkler's heat-responsive element operates; ordinary ratings are 135–170°F, intermediate 175–225°F, and high 250–300°F.
- Response time index (RTI)
- A measure of sprinkler thermal sensitivity; quick-response sprinklers have RTI ≤ 50 (m·s)^0.5 and standard-response have RTI ≥ 80 (m·s)^0.5.
- Quick-response sprinkler
- A sprinkler with a fast-acting heat-responsive element (RTI ≤ 50) that activates sooner, allowing a smaller design area and often reducing water demand.
- Standard spray sprinkler
- A sprinkler with a defined spray pattern, available as upright or pendent, typically listed for a minimum operating pressure of 7 psi.
- Sidewall sprinkler
- A sprinkler mounted on a wall or side of a pipe that discharges water outward and downward; spacing and placement rules differ from pendant and upright sprinklers.
- Hose allowance
- The additional water flow (gpm) added to sprinkler demand for manual hose streams; typically 100 gpm for light hazard, 250 gpm for ordinary hazard, and 500 gpm for extra hazard.
- Sprinkler spacing maximum
- The maximum distance between sprinklers on a branch line or between branch lines, generally 15 ft for light and ordinary hazards, with area limits per sprinkler.
- Obstruction rule
- Sprinklers must be positioned relative to walls and obstructions; obstructions up to 4 ft wide may require additional sprinklers depending on distance and depth.
- Dry-pipe system
- A sprinkler system where the piping is normally filled with air or nitrogen under pressure; water enters after a sprinkler opens, increasing the remote area by 30%.
- Preaction system
- A dry-pipe system that requires a separate detection event to admit water into the piping before sprinkler activation, reducing water damage risk.
- Deluge system
- A system where all sprinklers are open and water discharges simultaneously upon activation of a detection system; used for high-hazard occupancies.
- Main drain test
- A test that flows water from the main drain to verify the water supply and control valve status; results are compared to previous tests to detect changes.
- Waterflow alarm test
- A test that verifies the waterflow alarm activates within a specified time when a sprinkler or test valve is opened; required periodically per NFPA 25.
- Fire pump churn pressure
- The pressure produced by a fire pump at zero flow; it must not exceed 140% of the rated pressure to prevent overpressure of the system.
- Fire pump 150% flow
- At 150% of rated flow, a fire pump must produce at least 65% of its rated pressure; this ensures adequate performance during high-demand conditions.
- Net pump pressure
- The difference between discharge pressure and suction pressure across a fire pump; used to calculate the actual pressure added by the pump.
- Brake horsepower (BHP)
- The power required by a fire pump, calculated as (gpm × psi) / (1,714 × pump efficiency); used to size the driver and ensure adequate power.
- Suction pressure requirement
- The minimum residual pressure at the pump suction flange, typically 20 psi, that must be maintained under all flow conditions to avoid cavitation and ensure reliable operation.
- Fire pump controller
- A device that starts and stops the fire pump automatically or manually; it must be listed for fire pump service and sized per NFPA 20.
- Automatic transfer switch
- A switch that transfers the fire pump power source to an emergency generator within 10 seconds of a power loss, ensuring continuous pump operation.
- Weekly fire pump test
- A no-flow (churn) run of the fire pump for at least 10 minutes each week to verify automatic starting, alarms, and general condition.
- Annual fire pump flow test
- A test that flows water at multiple points (e.g., 100% and 150% of rated flow) and compares results to the manufacturer's curve to verify pump performance.
- Test header
- A piping arrangement with valves and hose connections used to flow water during fire pump testing; it must be capable of flowing at least 150% of rated capacity.
- Water supply curve
- A graph showing available pressure versus flow from a water source; the system demand point must fall below this curve for an adequate design.
- Static pressure
- The pressure in a water supply system when no water is flowing; it is used with residual pressure to determine the available water supply for fire protection.
- Residual pressure
- The pressure remaining in a water supply system when water is flowing at a given rate; it indicates the available pressure for firefighting operations.