Portable fire extinguishers Flashcards
When is the only time that portable fire extinguishers should be used?
For incipient fires and early growth fires.
How are fire extinguishers classified?
According to the fire size that they are designed to extinguish
What are the five fire extinguisher classes?
A, B, C, D, and K
What are the combustibles of class A fire extinguishers?
Textiles, paper, plastics, rubber and wood.
-They can all be extinguished with water, foam and dry chemicals.
How many litres of water would a 30-A fire extinguisher have?
5x30=150L
What is the upper limit for class A fire extinguishers in terms of liters?
5x40 = 200L
What combustibles does class B involve?
Flammable and combustible liquids and gases such as alcohol, gas, lubricating oils and propane.
What substances are uses in class B extinguishers?
CO2, dry chemicals, Class B foam.
How many square feet can a 500-B extinguisher cover when used by a civilian?
- the upper limit is 640 square feet.
What is a class C rating?
it is able to be used to extinguish charged electrical fires.
What combustibles are involved in Class D extinguishers?
Combustible metals like lithium, sodium. potassium
Why can’t water be used to extinguish combustible metal fires?
The water will react violently with the metal and could discharge molten metal.
Can firefighters use dry chemical extinguishers on combustible metal fires?
No only class D dry powders
Can firefighters use Class D extinguishers on other types of fires?
No
What kinds of fires are Class K extinguishers used for?
Combustible cooking oils.
What is inside of Class K extinguishers?
liquid alkaline mixture, known as wet chemical systems. it smothers the vapors of oil fires.
What are the four ways in which extinguishers act upon the combustibles?
- Smothering
- Cooling
- Chemical flame inhibition
- Saponification
What are the three methods of extinguisher expelation?
Manual pump
Stored Pressure
Pressure cartridge
In what two ways do AFFF extinguishers differ from stored-pressure water extinguishers?
- AFFF has a specified amount of AFFF concentrate mixed with water to form a foam mixture.
- AFFF has an air-aspirating foam nozzle, which creates better quality foam.
True or false? you can use an AFFF extinguisher for flowing fuels.
False, you can only use them for stagnant fuels
What are halotron extinguishers?
They are used in expensive electrical circuits like airplane cockpits and computer fires. They smother the fire without damaging the technology and the ozone layer.
When are CO2 extinguishers used?
They are used for Class B and Class C fires.
What is the difference between a dry chemical extinguisher and a dry powder extinguisher?
Dry chemical are used for Class ABC and class BC, while dry powder are used for Class D
When many extinguisher options are available, how to decide which is the best?
We want to minimize damage to life and property, while still being able to extinguish the fire. We must concider:
- Classification of the burning fuel
- Hazards to protect against
- Atmospheric conditions
- Ease of handling
- Rating of extinguisher
- Size and intesity of fire
- Availability of trained personel
- Any hazards to life or operational concerns
What is the PASS application method?
Pull Aim Squeeze Sweep
What four things should be inspected on a fire extinguisher before use?
External condition
Hose/nozzle
weight
pressure gauge
