NICET Special Hazards flashcards
NICET Special Hazards · 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.
- Clean agent total flooding
- A clean agent system discharges gaseous extinguishing agent into an enclosed space to achieve a design concentration that suppresses fire without leaving residue.
- CO2 total flooding hazard
- Carbon dioxide total flooding reduces oxygen and cools; because design concentrations can be lethal, it is generally limited to unoccupied spaces or spaces with strict safeguards.
- Wet chemical kitchen system
- Wet chemical systems use an alkaline solution sprayed on cooking oils and fats, causing saponification to form a soapy blanket that cools and smothers the fire.
- Dry chemical extinguishing
- Dry chemical agents are finely divided powders that interrupt the combustion chain reaction; they are effective on flammable liquid and gas fires but leave residue.
- Foam blanket principle
- Foam extinguishes flammable liquid fires by forming a blanket that separates the fuel surface from oxygen and suppresses vapor release, while water content provides cooling.
- Water mist system
- Water mist systems discharge fine droplets that cool the fire, displace oxygen, and wet surfaces; they use less water than conventional sprinklers and are covered by NFPA 750.
- Water spray system
- A water spray system uses fixed nozzles to apply water in a specified pattern and direction to protect a specific hazard such as a transformer or tank.
- Foam-water system
- A foam-water system combines foam concentrate with water and discharges through sprinklers or nozzles to blanket flammable liquids while providing cooling.
- Total flooding agent quantity
- The required clean agent quantity depends on enclosure volume, design concentration, agent properties, temperature, and altitude; calculations follow NFPA 2001 and manufacturer data.
- Enclosure integrity test
- A door-fan or pressurization test measures enclosure leakage to verify the space can hold the design concentration for the required hold time.
- Cross-zoning detection
- Cross-zoning requires two independent detectors to operate before agent discharge, reducing false discharges while maintaining rapid detection.
- Discharge delay
- A time delay before clean agent discharge allows occupants to evacuate and can be coordinated with alarms, doors, and HVAC shutdown.
- Nozzle placement rules
- Nozzles must be installed at listed spacing, height, and orientation for the hazard, following manufacturer coverage limits and the approved design.
- Wet chemical nozzle coverage
- Wet chemical nozzles are arranged to cover cooking appliances, hood plenums, and exhaust ducts, with listed spacing and aim points for each hazard.
- Foam application rate
- Foam application rate is the flow of foam solution per unit area, selected from NFPA 11 based on fuel type, foam concentrate, and hazard.
- Water mist pressure classes
- NFPA 750 classifies water mist systems by operating pressure: low pressure up to 175 psi, intermediate from 175 to 500 psi, and high pressure above 500 psi.
- Monthly visual inspection
- A monthly inspection checks gauges, agent cylinder condition, valve position, alarms, and obvious damage without discharging agent.
- Cylinder hydrostatic testing
- Agent cylinders must be hydrostatically tested or requalified at intervals set by NFPA and DOT, which vary by agent, cylinder type, and service.
- Wet chemical semiannual service
- NFPA 17A requires inspection and maintenance of wet chemical systems at least semiannually, including nozzles, cartridge pressure, and actuation components.
- Dry chemical semiannual service
- NFPA 17 requires dry chemical systems to be inspected and maintained at least semiannually, checking agent quantity, expellant gas, nozzles, and controls.
- Enclosure integrity retest
- Enclosure integrity should be retested after modifications to the enclosure, HVAC, or openings, and at intervals required by the adopted standard or authority.
- Foam proportioning test
- Foam proportioning tests verify the concentrate is mixed at the design percentage by measuring solution conductivity or refractivity during a flow test.
- Trip test
- A trip test verifies that a deluge or pre-action valve operates on detection signal and that alarms and interlocks function correctly.
- ITM record retention
- Inspection, testing, and maintenance records document dates, results, deficiencies, and corrective actions and must be retained for the period required by the code or AHJ.
- NFPA 2001
- NFPA 2001 is the standard for clean agent fire extinguishing systems, covering design, installation, commissioning, inspection, testing, and maintenance.
- NFPA 12
- NFPA 12 is the standard for carbon dioxide extinguishing systems, including total flooding and local application design and safety requirements.
- NFPA 17 and 17A
- NFPA 17 covers dry chemical systems, while NFPA 17A covers wet chemical systems; both address design, installation, maintenance, and testing.
- NFPA 11 and 16
- NFPA 11 covers foam extinguishing systems, and NFPA 16 covers foam-water sprinkler and spray systems for flammable liquid hazards.
- NFPA 750 and 15
- NFPA 750 covers water mist systems, and NFPA 15 covers water spray fixed systems for fire protection.
- Sequence of operations
- A sequence of operations describes detection, alarm, shutdown, discharge, and ancillary actions in the order they occur during a fire event.
- As-built documentation
- As-built drawings reflect the installed system, including pipe routing, nozzle locations, cylinder sizes, and device addresses, and support future maintenance.
- Authority having jurisdiction
- The AHJ is the organization or individual responsible for approving equipment, installations, and procedures under the adopted code.