NICET Special Hazards Level I flashcards

32 cards. Read the term and the definition here. The deck at the top of this page is optional.

Design area reduction quick-response

NFPA 13 permits a 25% reduction of the remote-area size for wet systems with quick-response sprinklers under flat ceilings of 10 ft or less, with a 1,500 sq ft minimum.

Sloped ceiling design area

Design area increases 30% for ceiling slopes over 2/12 up to 4/12, and an additional 30% per 2 in of slope beyond 4/12, per NFPA 13.

NFPA 13R scope

Covers automatic sprinkler systems in residential occupancies up to and including four stories, allowing reduced densities and omission of sprinklers in certain closets and bathrooms.

NFPA 13D scope

Applies to one- and two-family dwellings and manufactured homes, with a design goal of allowing occupants time to escape rather than protecting the structure.

NFPA 15 water spray

Covers fixed water spray systems using nozzles that produce specific spray patterns to protect hazards such as transformers, tanks, and flammable gas cylinders.

NFPA 16 foam-water systems

Covers the installation of foam-water sprinkler and foam-water spray systems, including discharge devices, piping, and foam concentrate supply.

NFPA 17A wet chemical

Standard for wet chemical extinguishing systems protecting commercial cooking appliances, hoods, and ducts; requires fuel and appliance shutdown upon actuation.

NFPA 2001 clean agent

Covers total flooding and local application clean agent systems using halocarbon or inert gases; design concentration includes safety factors over extinguishment values.

NFPA 11 foam systems

Standard for low-, medium-, and high-expansion foam systems; low-expansion foam is typical for hydrocarbon storage tanks and dike areas.

NFPA 750 water mist

Covers water mist systems, categorized by operating pressure: low below 175 psi, intermediate 175 to 500 psi, and high above 500 psi.

NFPA 12 CO2 systems

Covers carbon dioxide extinguishing systems for total flooding and local application; CO2 displaces oxygen, so occupied-area discharge requires pre-discharge alarm and delay.

NFPA 12A halon systems

Covers halon 1301 total flooding systems; halon production is phased out, so existing systems are maintained and replacements are considered at retrofit.

NFPA 17 dry chemical

Covers dry chemical extinguishing systems for total flooding and local application, commonly used for flammable liquid and gas hazards.

Remote area definition

The hydraulically most demanding area of sprinkler operation, whose size depends on occupancy classification and construction type under NFPA 13.

Density-area method

Sprinkler design method in which a discharge density in gpm per sq ft is applied over a specified remote area, determined from the occupancy hazard curve.

Hydraulic calculation purpose

Determines required pipe sizes and water supply by summing friction loss, elevation change, and discharge pressure to confirm adequate supply at the base of riser.

Safety factor in clean agent

Design concentration is set above the agent's extinguishment value by a factor to account for leakage and mixing uncertainty in the protected enclosure.

Hold time in clean agent

The period the design concentration must be maintained in the enclosure, typically 10 minutes, to allow occupant egress and prevent re-ignition.

Agent concentration calculation

Uses the enclosure volume, agent weight, and agent specific volume at the design temperature to confirm the required concentration is achieved.

Pre-discharge alarm requirement

Clean agent and CO2 total flooding systems in occupied spaces require audible and visual alarms before discharge, with a time delay for egress.

Foam expansion ratio

Ratio of finished foam volume to foam solution volume; low expansion is under 20:1, medium is 20:1 to 200:1, and high exceeds 200:1.

Foam concentrate proportioning

Mixing of foam concentrate with water at a specified percentage, commonly 3% or 6%, achieved by bladder tanks, pumps, or eductor systems.

Water mist droplet size

Water mist is defined by droplets with a Dv0.99 of 1,000 microns or less, distinguishing it from conventional sprinkler spray.

Wet chemical saponification

Chemical reaction between alkaline wet chemical agent and hot cooking oils that forms a soap-like foam, cooling the surface and sealing vapors.

Hood plenum protection

NFPA 17A requires protection of the cooking appliance, hood, and exhaust duct, with nozzles positioned per the manufacturer's listed design.

Manual pull station location

Required at a means of egress from the protected area, mounted at a listed height, and clearly identified for the cooking equipment system.

Dry chemical agent

Typically sodium bicarbonate or potassium bicarbonate based; extinguishes by interrupting the combustion chain reaction, not by cooling alone.

Total flooding application

Discharge of agent into an enclosed space to achieve a specified concentration throughout the volume, used for clean agent, CO2, and foam systems.

Local application

Agent is discharged directly onto the hazard rather than the entire enclosure, used for dip tanks, quench baths, and similar localized hazards.

Plan review submittal

Requires hydraulic calculations, agent quantity calculations, manufacturer data sheets, and nozzle layout drawings for approval before installation.

Acceptance test

Verifies system installation, including flow test, alarm operation, agent discharge test where permitted, and documentation of results for the authority having jurisdiction.

Inspection and maintenance

Periodic checks per NFPA 25 and system-specific standards, including agent weight verification, container pressure checks, and nozzle inspection.