Free Practice Questions for NFPA CFPS Exam

According to the Consumer Products Safety Commission (CPSC), the most common type of fabric used on upholstered furniture is cellulosic. Cellulosic fabrics are made from natural fibers derived from plants, such as cotton, linen, rayon, and hemp. Cellulosic fabrics account for about 51% of the total fabric weight used on upholstered furniture in the United States1. Cellulosic fabrics are popular because they are soft, comfortable, breathable, and versatile. However, they are also highly flammable and can contribute to the spread of fire if ignited2. Therefore, the CPSC has established a flammability standard for upholstered furniture that requires cellulosic fabrics to pass a smolder resistance test3. References:

Upholstered Furniture Business Education | CPSC.gov

Fire Fighting Foams - Chemguard

Standard for the Flammability of Residential Upholstered Furniture

Acetylene

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The ignition temperature of acetylene gas is 581° F (305° C). This is the minimum temperature required to ignite a gas or vapor in air without a spark or flame being present. The ignition temperature of acetylene gas varies according to composition, initial pressure, initial temperature, and water vapor content.As a typical example, an air mixture containing 30 percent acetylene by volume at atmospheric pressure can be ignited at about 581 °F (305°C)1.

References:Fuels and Chemicals - Autoignition Temperatures - The Engineering ToolBox;Ignition Temperatures and Group Classifications for Flammable Gases and Vapors;Is Acetylene Flammable? - Firefighter Insider;Ignition temperature acetylene - Big Chemical Encyclopedia;Acetylene Gas- its Characteristics and Safety Requirements

When using water mist as an extinguishing mechanism, the effectiveness of a fine mist depends on the momentum and direction of the spray relative to the fire. The momentum and direction of the spray determine how well the mist can penetrate the fire plume and reach the flame zone, where the mist droplets can evaporate and cool the fire, displace oxygen, and dilute the fuel vapors. The mist spray should have sufficient momentum to overcome the buoyancy and entrainment of the fire plume, and the direction of the spray should be aligned with the fire plume to avoid deflection and dispersion. The ability of the mist to directly spray on the fire, how much mist diverts to the compartment boundaries, and how much conductive heat the mist system will absorb are not the main factors affecting the extinguishing effectiveness of a fine mist.

References:Water Mist Systems Overview | NFPA;Engineering Relations for Water Mist Fire Suppression Systems;Effectiveness of Swirl Water Mist Nozzles for Fire Suppression

In the plastics industry, the four broad areas of processing arepolymerization,conversion,finishing, andrecycling1.Polymerization is the process of creating plastic resins from monomers or pre-polymers, using chemical reactions such as addition, condensation, or ring-opening2.Conversion is the process of transforming plastic resins into plastic products, using various methods such as injection molding, blow molding, extrusion, rotational molding, and thermoforming3.Finishing is the process of adding value to plastic products, such as coating, printing, welding, or assembling4.Recycling is the process of recovering plastic waste and converting it into new plastic products or raw materials, using mechanical, chemical, or biological methods5. Therefore,manufacturingis not one of the four broad areas of processing in the plastics industry, as it is a general term that encompasses all the stages of producing plastic products from raw materials.References:

Plastics Manufacturing: Types of Plastic and Processes - Deskera

Plastics industry - Wikipedia

Methods of Processing Plastic - Plastics Industry

Plastic recycling - Wikipedia

Polymerization - an overview | ScienceDirect Topics

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

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

Fire alarm systems audible appliances ratings are usually stated as a sound pressure level (SPL) at 10 ft (3.05 m) from the appliance. The SPL is measured in decibels (dB) and indicates the loudness of the sound produced by the appliance. The SPL at 10 ft (3.05 m) is used as a standard reference point for comparing different audible appliances and for designing fire alarm systems to meet the required audibility levels.References:

NFPA 72: National Fire Alarm and Signaling Code, 2019 Edition, Section 18.4.3.11

Fire Protection Handbook, 20th Edition, Volume 1, Chapter 7, Section 7.8.2.12

The measurement of a fluid’s resistance to flow is calledviscosity.Viscosity is the property of a fluid that describes how easily it can deform or move when subjected to a shear stress, such as the force exerted by a pipe wall or a pump1. A fluid with high viscosity, such as honey, resists flow and requires more pressure to overcome the friction between its layers.A fluid with low viscosity, such as water, flows easily and has less frictional resistance2.Viscosity affects the hydraulic properties of water for fire protection systems, such as the flow rate, pressure loss, and pump power3. Viscosity is usually expressed in units of pascal-second (Pa s) or centipoise (cP) for liquids, and is dependent on the temperature and composition of the fluid.References:

Viscosity | Definition, Facts, Formula, Units, & Examples

Viscosity – The Physics Hypertextbook

Fire Pump Types | NFPA

[12.4: Viscosity and Laminar Flow; Poiseuille’s Law]

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.

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 performance curve. 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.