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36 Cards in this Set

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The components of the fire triangle and the fire tetrahedron and are necessary for combustion to occur
(1) oxygen, (2) fuel, (3) Heat, (4) self-sustaining chemical reaction
(1) oxygen
being 21% in normal air this is usually plenty as approximately 16% is required for free burning and visible flame. Combustions will stop at 8%. Oxygen is also not flammable it just support combustion.
(2) Fuel
is the material being oxidized or burned in the combustion process.
(3) Heat
is the form of energy that raises temperature.
(4) Self-sustaining chemical reaction
allows for the continuous heating of a fuel mass and the production of vapors which join with oxygen to continue combustion. An example of a slow oxidation is rust which does not produce enough heat to reach ignition.
The three physical stages of fuels
The three physical stages of fuels are gas, liquid, and solid.
Flash point
the lowest temperature at which flammable or combustible products sufficient vapors to form a flammable mixture near the surface. Enough temp to get it to flash.
Fire point
is the temp at which a liquid fuel produces sufficient vapors to continuous bunting once ignited. Enough temp to get it to burn.
Ignition temp
is the lowest temp that a substance must be raised to start self-sustaining combustion.
Flammable limits/range
is the percentage of vapor in air that will burn once ignited. Most substances have an upper and lower flammable limit.
Boiling point
is the temp at which the evaporation rate exceeds the rate of condensation.
Specific gravity
is the weight of a substance compared to an equal weight of water (water=1). Less than one will float on water.
Vapor density
is the weight of a gas compared to an equal weight of air (air=1)
The different sources of heat energy are
Chemical, electrical, mechanical, nuclear, and solar
Chemical heat
is four things heat of combustion, spontaneous heating, heat of decomposition, and heat of a solution (heat release when a substance is dissolved in a liquid).
Electrical heat
is 6 things including resistance heat, induction heat, dielectric heat, heat from arcing, stat electricity, and lightning.
Resistance heat is electrical hat passing through a cord or appliance.
Induction heat is the heat of a electrical conductor.
Dielectric heat results from pulsating current on a nonconductive materials, like a microwave oven.
Heat from arching is when heat is interrupted ranging from 2000˚ to 7000˚ F.
Static electricity builds up of positive charge on one side and negative on the other.
Lighting is a huge form of electrical heat.
Mechanical heat
consist of Friction, friction sparks, and heat of compression-any time gas is compress.
Nuclear heat
consist of either Fission or Fusion. Fission is atoms splitting apart and fusion is atoms combining
● Solar heat
is generated by the sun.
the different units by which heat is measured are
Fahrenheit scale, Centrigrade/Celsius scale, BTU-British thermal unit, and Calorie.
Fahrenheit scale
1) 32˚F freezing temp of water
2) 212˚F boiling temp of water
Centigrade/Celsius scale
1) 0˚C freezing temp of water
2) 100˚C boiling temp of water
BTU-British Thermal Unit
is the Heat is require to raise one pound of water 1˚F.
Calorie
is the heat require to raise one gram of water 1˚C.
Class A Fire
ordinary combustibles (wood, trash, cloths, furniture) where cooling is the normal extinguishment method.
Class B Fire
flammable liquid and gases which is extinguish oxygen exclusion, cooling, fuel removal, and chemical flame inhibition.
Class C Fire
energize electrical equipment which is extinguish by pulling the plug and opening electrical circuit.
Class D Fire
combustible metals which is extinguish by special agents normally required for specific fuels (these may have no pressure to the extinguisher, as pressure would make it worse)
Class K Fire
cooking oil used for commercial operations
How does heat transfer?
Conduction, convection, and radiation.
Conduction
is when heat is transfer by direct contact from one body to another, point to point transfer of heat energy.
Convection
is when heat is transfer by movement of heated liquid or gases.
Radiation
is when heat is transfer by heat energy giving off of a structure and absorb by another, no point to point transfer.
Signs of a potential flashover are:
Heat build up
Rollover: when flames move through the unburned gases at ceiling level.
Thick dark smoke
Free burning of the fire
Survival Techniques with flashover
Recognize warning signs
Avoid disorientation remain calm and think
Full PPE on
Know the point of return-get out-escape is possible if 5 feet from exit as a firefighter can travel 2.5 feet a second without a hose and has only 2 seconds to exit when a flashover occurs.
Get as low as possible
Open the nozzle on full fog overhead
Backdraft indicators
Smoke under pressure.
Black smoke becoming thick dense gray-yellow.
Confinement and excessive heat
Little or no visible flame
Smoke leaves structure in puffs or intervals, looks like it is breathing
Smoke stained windows
Muffled sounds
Sudden inrush of air when opening is made.