CFPS Certified Fire Protection Specialist (CFPS) Questions and Answers

Fire pump

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The correct answer is B.Safety is one of the criteria for selecting the power source for driving fire pumps, according to NFPA 20, Chapter 9.1.1.11. Reliability, adequacy, and economy are the other criteria mentioned in the same chapter. Efficiency, adaptability, and ecology are not explicitly stated as criteria in NFPA 20, although they may be considered as secondary factors in some cases.

1:Pump Installation: Everything About Electric and Diesel Driven Fire …

Fire pump

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A suction in-line fire pump has a pressure range that can exceed 300 psi (2,068 kPa). This type of pump is a centrifugal pump that is installed in a vertical position with the suction and discharge connections in the same line. The pump is designed to handle high pressures and flows, and it is suitable for high-rise buildings and other applications that require high head.According to NFPA 20, Standard for the Installation of Stationary Pumps for Fire Protection, a suction in-line fire pump can have a rated pressure of up to 360 psi (2,482 kPa)1.The other types of fire pumps mentioned in the question have lower pressure ranges, as shown in the table below2:

Type of fire pump

Pressure range (psi)

Pressure range (kPa)

Horizontal-end suction

40 to 150

276 to 1,034

Split case

40 to 150

276 to 1,034

Vertical turbine

40 to 150

276 to 1,034

Suction in-line

40 to 360

276 to 2,482

References:NFPA 20: Fire pump design | Consulting - Specifying Engineer;Understanding the Basics of Fire Pumps | Pumps & Systems

Aqueous film-forming agents (AFFF) are synthetic foam concentrates that can be proportioned into final concentrations of 1%, 3%, and 6%, depending on the type of fuel and application method12. AFFF forms a thin aqueous film on the surface of the flammable liquid, which prevents vapor release and provides rapid fire knockdown and extinguishment3. AFFF is suitable for Class B fires involving hydrocarbon fuels such as gasoline, diesel, kerosene, etc. References:

• Fire Fighting Foams - Chemguard
• Extinguishing foam: types, operation and application areas
• [NFPA 11: Standard for Low-, Medium-, and High-Expansion Foam]

The two classes of fire models arephysical and mathematical. Physical fire models are scaled-down representations of real fire scenarios, using laboratory experiments and measurements to study the fire behavior and effects.Physical fire models can be used to test hypotheses, validate mathematical models, and provide empirical data for fire analysis1. Mathematical fire models are numerical or analytical solutions of the equations that govern the fire phenomena, such as heat transfer, fluid dynamics, combustion, and chemical kinetics.Mathematical fire models can be used to simulate fire scenarios, predict fire outcomes, and optimize fire protection systems2. There are two major categories of mathematical fire models: zone models and field models. Zone models divide the fire compartment into two or more homogeneous zones, such as upper and lower layers, and apply mass and energy conservation equations to each zone.Zone models are relatively simple, fast, and easy to use, but they have limitations in accuracy and applicability3. Field models solve the partial differential equations that describe the fire-driven fluid flow and heat transfer in three dimensions, using computational fluid dynamics (CFD) techniques.Field models are more detailed, realistic, and flexible, but they require more computational resources and expertise4.References:

• Fire modelling with Computational Fluid Dynamics - BRE Group
• Fire modeling programs | NIST
• interFIRE, A site dedicated to improving fire investigation worldwide.
• Computer Fire Models for Fire Investigation and Reconstruction

Computers and other information technology equipment are particularly susceptible to heat, steam, and combustion products, which can damage their sensitive components, cause data loss or corruption, and impair their functionality.Therefore, fire protection for IT equipment should consider the potential sources of heat, steam, and combustion products, such as electrical faults, flammable liquids, dust accumulation, water-based sprinklers, or smoke from adjacent areas, and implement appropriate measures to prevent, detect, and suppress fires, as well as to minimize the exposure of IT equipment to these hazards1234.References:Standard for the Fire Protection of Information Technology Equipment;Fire Protection of Computer Rooms—Legal Obligations and Best Practices - ISACA;Exploring Requirements for Information Technology Equipment;Demystifying IT room protection requirements - Consulting.

The data of a pre-incident plan should be evaluated after an incident, as part of the post incident critique or analysis. This is to assess the accuracy, completeness, and usefulness of the pre-incident plan, and to identify any changes or updates needed based on the lessons learned from the incident.Evaluating the pre-incident plan after an incident can also help improve the emergency response performance and the fire safety management of the site.References:123

Fire pump

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A multistage centrifugal fire pump is defined as having two or more impellers on one shaft as a single unit. A multistage centrifugal pump is a type of centrifugal pump that uses multiple impellers to increase the pressure and flow of water.Each impeller acts like a single-stage pump within a chain of pumps, and the water passes through each impeller in series, gaining pressure and velocity at each stage1.A multistage centrifugal fire pump is used to provide high-pressure water for fire protection systems, especially in high-rise buildings or large industrial facilities2.A multistage centrifugal fire pump can be driven by an electric motor, a diesel engine, or a steam turbine3.References:

• Our Guide to Multistage Centrifugal Pumps | C&B Equipment
• Fire Pump Types | NFPA
• NFPA 20: Changes to the fire pump standard - Consulting

According to the web search results, titanium is the pure metal in its solid form in oxygen that has the highest ignition temperature in degrees Fahrenheit.The spontaneous-ignition temperature of titanium in the solid phase (below melting) is about 3020°F (1660°C)1.Aluminum, potassium, and zirconium have lower ignition temperatures in the solid phase, ranging from 1292°F (700°C) to 1652°F (900°C)23.References:

• IGNITION OF METALS IN HIGH PRESSURE OXYGEN2
• Combustion of Metals in Oxygen-Enriched Atmospheres3
• High-temperature oxidation and ignition of metals1

The correct answer is B. In wide-open spaces, the sound pressure level (SPL) decreases by 6 decibels (dB) every time the distance from the source is doubled. This is known as the inverse square law of sound propagation, which states that the intensity of sound is inversely proportional to the square of the distance from the source.For example, if the SPL at 1 meter from the source is 100 dB, then the SPL at 2 meters from the source is 94 dB, and the SPL at 4 meters from the source is 88 dB123

The minimum pipe diameter size for direct discharge of steam inside a water tank is 2 in. (50 mm), according to NFPA 13, Standard for the Installation of Sprinkler Systems. This is to prevent water hammer, noise, and vibration caused by the rapid condensation of steam when it contacts the water. The pipe should also be equipped with a check valve to prevent backflow of water into the steam source.References: NFPA 13, Standard for the Installation of Sprinkler Systems, 2023 Edition, Chapter 8, Section 8.16.4.5.3; NFPA Fire Protection Handbook, 21st Edition, Chapter 14, Section 14.3.4.2.

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 …

Cellulose nitrate products begin to decompose at about 300 °F (150 °C). This is the temperature at which the nitrate ester bonds start to break down and release nitric acid, which further catalyzes the decomposition. The decomposition temperature depends on the nitrogen content, the stabilizers, and the external heating rate of the cellulose nitrate. Higher nitrogen content, lower stabilizer concentration, and faster heating rate lower the decomposition temperature and increase the risk of thermal runaway.

References:Nitrocellulose - Wikipedia;Comparative analysis of stable decomposition and combustion kinetics of nitrated cellulose;Degradation of aged nitrocellulose investigated by thermal analysis methods;Nitrocellulose;Effect of stabilizers and nitrogen content on thermal properties of nitrocellulose

An as built plan review is a type of plan review that may provide information about a modification such as the removal of an abandoned underground flammable liquid tank. An as built plan review is conducted after the construction or alteration of a building orsystem is completed and before the final approval or acceptance by the AHJ. An as built plan review verifies that the building or system conforms to the approved plans and specifications and complies with the applicable codes and standards. An as built plan review may also identify any changes or deviations from the original plans that occurred during the construction or alteration process, such as the removal of an underground tank.References:

• NFPA 1: Fire Code, 2018 Edition, Section 1.12.8.1.11
• Fire Protection Handbook, 20th Edition, Volume 1, Chapter 5, Section 5.2.3.42

Two-dimensional models are not a common type of road tunnel fire models. Most road tunnel fire models are either one-dimensional, zone, or field models. One-dimensional models use a simplified approach to describe the fire and smoke behavior along the tunnel axis, assuming uniform conditions across the tunnel cross-section. Zone models divide the tunnel into two or more zones, each with uniform properties, and apply mass and energy conservation equations to each zone. Field models use computational fluid dynamics (CFD) to solve the governing equations for mass, momentum, energy, and species transport in a three-dimensional grid, capturing the spatial and temporal variations of the fire and smoke phenomena. Two-dimensional models are rarely used for road tunnel fire simulations, as they cannot account for the complex three-dimensional effects of fire and ventilation in tunnels.

References:Design Fires in Road Tunnels | The National Academies Press;CFD Modelling of Fire Ventilation in Road Tunnels - Academia.edu;Findings of the International Road Tunnel Fire Detection Research …1

Response Time Index (RTI) is a measure of thermal sensitivity of a sprinkler’s activation. It indicates how quickly the sprinkler responds to the heat from a fire. RTI is calculated by using the operating time, operating temperature, air temperature, air velocity, and conductivity factor of the sprinkler. RTI is independent of the gas velocity but depends on the properties of the sprinkler head such as mass, specific heat capacity andsurface area of the thermal sensing element. RTI is used to classify sprinklers into fast response or standard response categories.

References:The Basics of Sprinkler Thermal Characteristics | NFPA;Sprinkler Characteristics According to NFPA 13 - Fire Protection …;Response time index (RTI) - Oil and Gas Drilling Glossary;RESPONSE TIME INDEX OF SPRINKLERS - Department of Building Environment …

25%

Explosions or fires from flammable gas or oil fuel vapor-air mixtures may be prevented by ventilation and controls that keep the flammable vapor content below 25% of the lower flammable limit (LFL) of the vapor-air mixture, according to the web search results. The LFL is the lowest concentration of a gas or vapor in air that can produce a flash of fire in the presence of an ignition source. Below the LFL, the mixture is too lean to burn. The LFL varies for different gases and vapors, and it is usually expressed as a percentage by volume of air at 25°C and atmospheric pressure. For example, the LFL of methane is 4.4%, which means that a mixture of methane and air with less than 4.4% methane cannot ignite. To prevent explosions or fires, the concentration of flammable gases or vapors should be kept below 25% of their LFL, which is equivalent to 1.1% methane in this case. Ventilation, natural or mechanical, is one of the methods to achieve this by diluting the flammable gases or vapors with fresh air.Controls, such as gas detectors, alarms, valves, and interlocks, are another method to monitor and regulate the flammable gas or vapor levels and prevent them from reaching dangerous concentrations1234

The weight of items such as furnishings, people, and equipment is called dead load. Dead load is the permanent load that is applied to a structure or a component of a structure1. It includes the weight of the structure itself, as well as any fixed attachments or equipment2. Dead load is one of the factors that determines the fire resistance rating of a structure or a component3. References:

• NFPA 557: Standard for Determination of Fire Loads for Use in Structural Fire Protection Design
• An Overview of Fire Protection for Structural Engineers
• SFPE Handbook of Fire Protection Engineering, 5th edition

According to NFPA 13, Table 17.4.2.1 (a), the maximum distance between hangers for an automatic fire sprinkler system for a threaded lightwall steel pipe of 2 in. diameter is 10 ft. This is done to ensure that there are not long stretches of unsecured piping that could sag, leak, or break. The distance between hangers may vary depending on the type of pipe, the type of hanger, and the seismic design category of the building.References:NFPA 13, Table 17.4.2.1 (a);Hangers and Support of Sprinkler System Piping | NFPA | NFPA.

The answer is A. According to NFPA 30: Flammable and Combustible Liquids Code, 2021 Edition, Chapter 14, lockers used for the storage of flammable or combustible liquids shall not exceed 1500 ft2 (139 m2) gross floor area. This limit applies to both indoor and outdoor lockers.Lockers are defined as self-contained, prefabricated structures that are designed to store hazardous materials and that are equipped with fire protection features, such as fire-resistance-rated walls, doors, and roofs, automatic sprinklers, spill containment, and ventilation12

According to the web search results, the goals of the first edition of NFPA 13D were to provide sufficient time for safe egress or rescue, economic viability, and limit damage to the dwelling. The first edition of NFPA 13D was published in 1975 and was based on the concept of a “life safety” sprinkler system that was intended to protect the occupants of one- and two-family dwellings and manufactured homes from fire.The first edition of NFPA 13D stated that the system was not designed to protect the property or contents from fire damage, but rather to provide a tenable environment for escape or rescue1.The first edition of NFPA 13D also recognized the need for economic viability of the system, and therefore allowed for reduced water supply and piping requirements compared to other sprinkler standards2.The first edition of NFPA 13D did not explicitly state the goal of limiting damage to the dwelling, but it implied that the system would have some beneficial effect on the fire spread and severity by stating that the system was designed to prevent flashover in the room of fire origin1.References:

• NFPA 13D: Standard for the Installation of Sprinkler Systems in One- and Two-Family Dwellings and Manufactured Homes, 1975 Edition, Section 1-11
• Fire Protection Handbook, 20th Edition, Volume 1, Chapter 8, Section 8.2.1.22

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. According to the web search results, 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

Fire pump

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Typical fire pump drivers reach maximum brake horsepower (BHP) between 140% and 170% of rated capacity, depending on the type and size of the pump. This means that the driver must be able to provide enough power to operate the pump at its peak efficiency point, which is usually beyond the rated capacity. The rated capacity is the flow rate at which the pump is designed to deliver a certain pressure, as specified by NFPA 20, Standard for the Installation of Stationary Pumps for Fire Protection. The maximum BHP is the highest power output required by the pump at any point on its performancecurve. The driver must be sized to match the maximum BHP of the pump, with some allowance for service factor and safety margin.References:Understanding the Basics of Fire Pumps | Pumps & Systems;How are Engines and Motors Sized for Fire Pumps?; NFPA 20, Standard for the Installation of Stationary Pumps for Fire Protection, 2023 Edition, Chapter 4, Section 4.7.

According to the CDC, exposure to hydrogen fluoride at concentrations of less than 50 ppm for two minutes may cause mild eye and upper respiratory tract irritation. The severity of the effects depends on the concentration, duration, and route of exposure, as well as the individual’s susceptibility. Higher concentrations or longer exposures can cause more serious health effects, such as pulmonary edema, skin burns, or systemic toxicity.References:CDC | Facts About Hydrogen Fluoride (Hydrofluoric Acid); [Hydrogen Fluoride (HF) | Medical Management Guidelines | Toxic Substance Portal | ATSDR]2; [Hydrogen Fluoride and Hydrofluoric Acid (HF) - GOV.UK]3.