Fire Behavior and Combustion Flashcards
7 cards from real CPS practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Fire Behavior and Combustion flashcards as text
What is the fourth element added to expand the fire triangle into the fire tetrahedron?
Answer: Uninhibited chain reaction
The fire tetrahedron adds the uninhibited chemical chain reaction as a fourth element, recognizing combustion as a self-sustaining chemical process.
What is pyrolysis?
Answer: The chemical decomposition of a material by heat, producing flammable gases
Pyrolysis is the thermal decomposition of solid or liquid fuels by heat, releasing flammable vapors that then mix with oxygen and ignite.
What is rollover (flameover) in a structure fire?
Answer: When flames roll across the ceiling through accumulated unburned gases ahead of the main fire
Rollover occurs when unburned flammable gases accumulate at the ceiling level and ignite, creating flames that roll across the ceiling in advance of the main fire.
Which fire class involves fires in flammable and combustible liquids and gases?
Answer: Class B
Class B fires involve flammable liquids (gasoline, oil) and flammable gases, which require foam, CO2, or dry chemical agents for suppression.
What does the lower flammable limit (LFL) of a gas indicate?
Answer: The minimum concentration of gas in air required to sustain combustion
The lower flammable limit is the minimum concentration of a fuel gas mixed with air below which the mixture is too lean to ignite and sustain combustion.
How does convection transfer heat in a fire environment?
Answer: Through the movement of heated gases and liquids carrying thermal energy
Convection transfers heat through the physical movement of heated air and gases, which is why hot gases and smoke rise and spread fire to upper floors.
What is thermal layering (thermal balance) in a burning structure?
Answer: The stratification of hot gases near the ceiling and cooler air near the floor
Thermal layering refers to the stratification of smoke and gases by temperature, with hottest gases at ceiling level and relatively cooler air near the floor.