Critical radiant flux is used to classify interior floor finishes . Critical radiant flux is a measure of the minimum radiant heat energy required to sustain flame propagation on a floor material or covering. It is determined by exposing a specimen to a radiant heat gradient and observing the distance from the ignition point to the flame-out point. The shorter the distance, the higher the critical radiant flux and the better the fire performance of the floor material or covering 1 . Critical radiant flux is used to classify floor materials and coverings according to their fire hazard and resistance, and to specify the minimum requirements for different occupancies and applications 2 . For example, the International Building Code (IBC) requires that interior floor finishes and coverings in exit access corridors and exit enclosures have a critical radiant flux of not less than 0.45 W/cm2, while those in other spaces have a critical radiant flux of not less than 0.22 W/cm2 3 . Critical radiant flux is also used to evaluate the fire safety of floor materials and coverings in transportation vehicles, such as aircraft, trains, and buses 4 .

According to NFPA 400, Table 5.2.1.1.3, the maximum allowable quantity (MAQ) of a nonliquified oxidizing gas per control area in an unsprinklered area is 2000 ft3 (56 m3) when stored in a gas cabinet. This quantity can be increased by 100% if the area is sprinklered or by 300% if the area is also provided with a gas detection system. A gas cabinet is a ventilated enclosure for the storage of one or more compressed gas containers that provides a method of control for potential leakage or fire exposure hazards [NFPA 400, 3.3.32]. References : NFPA 400, Table 5.2.1.1.3 ; NFPA 400, 3.3.32 ; NFPA 400, 5.2.1.1.3.1 ; NFPA 400, 5.2.1.1.3.2 .

The minimum carbon dioxide design concentration for extinguishment of an ethylene fire is 43% . This is based on the cup burner method, which is a standard test to determine the flame extinguishing concentration of a gaseous agent for a liquid fuel. Ethylene is a flammable gas that can form a liquid under pressure. The cup burner method involves placing a liquid fuel in a metal cup with a central nozzle, and flowing a gaseous agent through the nozzle to create a diffusion flame. The gaseous agent is gradually increased until the flame is extinguished. The minimum concentration of the gaseous agent required to extinguish the flame is recorded as the flame extinguishing concentration 1 . According to a study by NIST, the flame extinguishing concentration of carbon dioxide for ethylene was found to be 43% 1 . This value is also consistent with the NFPA 12 standard, which specifies the minimum design concentrations of carbon dioxide for various fuels, including ethylene 2 .

A proprietary fire alarm system is a type of fire alarm system that transmits signals that are permanently recorded at a constantly attended supervising station located either at the protected premises or at another location of the property owner. A proprietary fire alarm system is owned and operated by the property owner or the owner’s agent. A proprietary fire alarm system is intended to provide fire alarm service to a single property or a campus of related properties. References :

NFPA 72: National Fire Alarm and Signaling Code, 2019 Edition, Section 3.3.105.1 1

Fire Protection Handbook, 20th Edition, Volume 1, Chapter 7, Section 7.2.1.1 2

The removal of flammable vapors by displacement for cleaning a storage tank can be accomplished by displacement with air, inert gas, and water. Water is a common method of displacing flammable vapors from tanks, as it is readily available, inexpensive, and non-reactive with most fuels. Water can be sprayed into the tank to create a water seal that prevents the vapors from escaping and reduces the oxygen concentration in the tank. Water can also be used to rinse the tank walls and remove any residual fuel. However, water displacement may not be suitable for some tanks that contain water-sensitive or water-soluble fuels, or for tanks that have limited drainage or disposal facilities.

References : ust permanent closure requirements - Nevada ; A Guide to Safety in Confined Spaces - CDC Stacks ; Fire Explosion Prevention – Visual Encyclopedia of Chemical Engineering …

The types of overspray collectors associated with spray booths can be categorized into venturi scrubbers, waterfall scrubbers, dry filter, and cartridge filter. Venturi scrubbers use a high-velocity water spray to capture the overspray particles in a turbulent zone. Waterfall scrubbers use a curtain of water flowing over a perforated plate to wash down the overspray. Dry filter collectors use a series of filters, such as paper, fiberglass, or synthetic media, to trap the overspray. Cartridge filter collectors use pleated cartridges with high surface area and efficiency to capture the overspray. These collectors also have a self-cleaning mechanism that uses compressed air to dislodge the overspray from the cartridges.

References : Spray Booth Filters: Types and Selection ; Spray Booths and Paint Finishing Operations ; Spray Booth Filters: Types and Selection ; Spray Booth Filters: Types and Selection ; Spray Booth Filters: Types and Selection

Class 3 unstable reactive gas is defined as a material that in itself is capable of detonation or explosive decomposition or reaction at normal temperatures and pressures with a strong initiating source or if heated under confinement. This class of gas readily undergoes violent chemical change at elevated temperatures and pressures.

References : NFPA 55: Compressed Gases and Cryogenic Fluids Code, 2016 Edition, Section 3.3.51.14.3 ; International Fire Code, 2015 Edition, Appendix E, Section E102.1.1