NFPA CFPS - Certified Fire Protection Specialist (CFPS)

Wet chemical extinguishing agents, such as potassium acetate and potassium citrate, when sprayed on a grease fire, extinguish the fire by smothering and cooling. The wet chemical agent reacts with the hot grease and forms a layer of soap-like foam on the surface of the fat, which acts as an insulation between the hot grease and the atmosphere, preventing the escape of combustible vapors and oxygen supply.The wet chemical agent also absorbs heat from the grease and lowers its temperature below the ignition point12

References:

What is the Difference Between a Wet and Dry Chemical Fire …

Wet Chemical (Class K) Fire Extinguisher - Portable - WFX

0.62

The discharge coefficient of a solid stream nozzle for a standard orifice with sharp edges is a dimensionless number that indicates the ratio of the actual flow rate to the theoretical flow rate of the nozzle. The discharge coefficient depends on the geometry and the flow conditions of the nozzle.the typical discharge coefficient of a solid stream nozzle for a standard orifice with sharp edges is about 0.62, which means that the actual flow rate is about 62% of the theoretical flow rate.This value is based on the experiments conducted by the National Bureau of Standards (now NIST) and reported in the paper “Discharge Coefficients of Fire Nozzles”1.The paper also provides a formula to calculate the discharge coefficient for different nozzle diameters and pressures123

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

A Class I standpipe system provides 2 1/2 in. (65 mm) hose connections at designated locations in a building for use by the fire department. A Class I standpipe system is intended to supply water for fire fighting operations by trained personnel using hoses of 1 1/2 in. (40 mm), 1 3/4 in. (45 mm), or 2 in. (50 mm) nominal diameters. A Class I standpipe system is required to deliver a minimum flow rate of 250 gpm (946 L/min) at a minimum residual pressure of 100 psi (6.9 bar) at the most remote hose connection.References:

NFPA 14: Standard for the Installation of Standpipe and Hose Systems, 2019 Edition, Section 3.3.4.11

Fire Protection Handbook, 20th Edition, Volume 1, Chapter 8, Section 8.2.1.12

The ratio of the weight of a solid or a liquid substance to the weight of an equal volume of water is referred to asspecific gravity. Specific gravity is a dimensionless quantity that is defined as the ratio of the density of a substance to the density of the water at a specified temperature.The density of water at 4 0C is commonly used as a reference point1. Specific gravity can be calculated using the following formula:

SG=fracrhosubstance​rhoH2​O​

where rhosubstance​ is the density of the substance and rhoH2​O​ is the density of water. Specific gravity can be used to compare the relative densities of different substances and to determinewhether a substance will sink or float in water.A substance with a specific gravity less than 1 will float in water, while a substance with a specific gravity greater than 1 will sink in water2.

For example, the specific gravity of gold is 19.3, which means that gold is 19.3 times denser than water. Therefore, gold will sink in water. The specific gravity of ice is 0.92, which means that ice is 0.92 times denser than water. Therefore, ice will float in water.

References:

Specific gravity | Formula, Units, & Equation | Britannica

Specific Gravity - Definition, Calculation, Solved Examples, FAQs - BYJU’S

According to NFPA 230: Standard for the Fire Protection of Storage, 2015 Edition, building codes should limit the size of an unsprinklered facility used for the processing and storage of Municipal Solid Waste (MSW) built of type V construction to 7,500 ft2 (697 m2). This is based on the assumption that the MSW has a heat release rate of 18,000 Btu/ft2-min (200 kW/m2) and a fire growth rate of 0.046 min-1.Type V construction is defined as a type of construction in which the structural elements, exterior walls, and interior walls are of any materials permitted by the code123

References:

NFPA 230: Standard for the Fire Protection of Storage

5 Types of Construction per the IBC | Building Code Trainer

2.4 MUNICIPAL SOLID WASTE LANDFILLS - U.S. Environmental Protection Agency

According to NFPA 70: National Electrical Code (NEC) 2020 Edition, Article 230.71(A), each service shall have only one disconnecting means unless the requirements of 230.71(B) are met, which provide four specific service configurations. In each configuration, there shall be not more than six switches or sets of circuit breakers, or acombination of not more than six switches and sets of circuit breakers, per service grouped in any one location. Therefore, the maximum number of additional switches or circuit breakers allowed for a separate service is six.References:

NFPA 70: National Electrical Code (NEC) 2020 Edition, Article 230.71(A) and (B)12

ElectricalLicenseRenewal.com, 230.71 Maximum Number of Disconnects3

According to NFPA 72-2023, the National Fire Alarm and Signaling Code, sound meters used to test notification appliances in fire alarm systems shall comply with ANSI S1.4-1983 (R2006), Specification for Sound Level Meters, or ANSI S1.42-2001 (R2007), Design Response of Weighting Networks for Acoustical Measurements. These standards are equivalent to IEC 61672-1:2002, Electroacoustics – Sound Level Meters – Part 1: Specifications. The sound meters shall also have a frequency range that includes at least 100 Hz to 10 kHz and a dynamic range that includes at least 45 dB to 120 dB12

References:

NFPA 72-2023: National Fire Alarm and Signaling Code, Section 18.4.5.21

Testing fire alarm sounders to BS EN 5839 - NoiseNews2