Fire Extinguishers Flashcards
Class A
Ordinary combustibles
extinguished with water
class A foam
dry chemical
Green triangle
Class B
Flammable liquids
Extinguished with CO2
Dry chemical
Class B foam
Red square
Class C
Electrical
Turn power source off
Treat as Class A or B
Blue circle
Class D
Metals
Use dry powder to extinguish
Do not use dry chemical
Yellow star
Class K
Combustible cooking liquids
Extinguish with wet chemical
Portable extinguishers
Black octagon
Smothering
chain breaking
saponification
Smothering- Excludes oxygen
chain breaking- Interrupts chemical chain reaction
saponification- Forms oxygen excluding foam
Mechanisms to expel
Manual pump
Stored pressure
Pressure cartridge
Manual pump- physical pressure forces agent out nozel
Stored pressure- compressed Air or inert gas forces agent out nozzle
Pressure cartridge- external expelling forces agent out nozzle
Types of extinguishers
Pump type Stored pressure Water misted store pressure Wet chemical Aqueous film forming foam Clean agent
Pump type- use in class A Stored pressure- small class a fires Water misted store pressure-class C Wet chemical- class K Aqueous film forming foam-class B Clean agent- smothers A and B
CO2 extinguisher
Class B and C fires
dispersed by wind
limited reach
Dry chemical
Regular- B:C rated
Multipurpose- A:B:C rated
May react chemically with others
Non toxic
May reduce visibility may create respiratory problem
Cartridge operated and stored pressure
Steps- knock down flames then smother area
Dry powder
Class D metals
No single agent works on all metals
Creates smothering blanket
Steps- cover fire w powder, leave undisturbed
Class A ratings
1-A through 40-A
1-A 5L of water
2-A 10L of water
Class B ratings
1-B through 640-B
BasedOn the approximate square foot area of a flammable liquid fire a non-expert can extinguish
Class C ratings
Not extinguishing compatibility test
Tester to determine nonconductivity
Class D ratings
No Numerical rating
Based on type of combustible metal
Class K
No numerical rating
Based on capability of saponifying cooking oils
3 types of multipurpose class extinguishers
Class abc class ab class bc
2main goals of extinguishers
Minimize risk to life and property
effectively extinguish fire
Factors determing type of wxtinguisher
Fuel classification rating life hazards training atmosphere conditions ease of handling operational concerns
PASS
Pick up
approach
squeeze
sweep
Factors determining value
Serviceability
Accessibility
Simplicity
