to be effective an extinguisher: must be readily accessible in working order suitable for the hazard...
TRANSCRIPT
To be effective an extinguisher:
To be effective an extinguisher:
Must be readily accessible
In working order
Suitable for the hazard
Large enough to control the size fire
Must be readily accessible
In working order
Suitable for the hazard
Large enough to control the size fire
RemoveOxygenHeatFuel
RemoveOxygenHeatFuel
EXINGUISHING PRINCIPLESEXINGUISHING PRINCIPLES
Chemical InhibitionChemical Inhibition
WATER FIREEXTINGUISHERS
Extinguisher Characteristics:
Size: 2.5 gallons
Discharge distance: 30-40 feet
Duration: 30-60 seconds
Method of expelling agent: pump or pressure
WATER FIREEXTINGUISHERS
Agent Characteristics:Freezing temperature: 32oFHigh surface tensionNeeds expellant force
Extinguishment principle: remove heat/cooling
Class A fires only
WATER FIREEXTINGUISHERS
Advantages
LimitationsConducts electricityFreezesHigh surface tensionReacts with certain chemicals
Absorbs large amounts of heat
Can be used with specialized agents
Dry Chemical ExtinguishersDry Chemical Extinguishers
Extinguisher Characteristics:
Size: 2.5 to 350 pounds
Discharge distance: 5-20 feet
Duration: 8-25 seconds
Method of expelling agent: cartridge/stored pressure
Sodium bicarbonate: ordinary
Potassium bicarbonate: Purple K
Potassium chloride: Super K
Monammonium phosphate: multipurpose, Tri-class
Sodium bicarbonate: ordinary
Potassium bicarbonate: Purple K
Potassium chloride: Super K
Monammonium phosphate: multipurpose, Tri-class
Agents:Agents:
Dry Chemical ExtinguishersDry Chemical Extinguishers
Dry Chemical ExtinguishersDry Chemical Extinguishers
Extinguishment principle:Extinguishment principle:
Uses:Uses:
Breaking chain reaction
Tri-class: smothering
Breaking chain reaction
Tri-class: smothering
Class A: Tri-class Class B & C: all types
Class A: Tri-class Class B & C: all types
Dry Chemical ExtinguishersDry Chemical ExtinguishersAdvantagesAdvantages
LimitationsLimitationsBreathing difficultiesInsulating qualitiesCorrosive propertiesNot flash back resistiveChemicals not interchangeableSome not compatible with foam
Breathing difficultiesInsulating qualitiesCorrosive propertiesNot flash back resistiveChemicals not interchangeableSome not compatible with foam
NontoxicNonconductiveQuick flame knockdown
NontoxicNonconductiveQuick flame knockdown
Carbon Dioxide ExtinguishersCarbon Dioxide Extinguishers
Extinguisher Characteristics:
Size: 2.5 to 100 pounds
Discharge distance: 3-8 feet
Duration: 8-30 seconds
Method of expelling agent: stored pressure
Carbon Dioxide ExtinguishersCarbon Dioxide Extinguishers
Agent Characteristics:
Extinguishment principle: smothering
Class B and C fires, limited effect on Class A
Normally a gas
1.5 times heavier than air
Low temperature
Can be stored as liquid
Carbon Dioxide ExtinguishersCarbon Dioxide Extinguishers
Advantages
Limitations
Visibility
Noise
Short range
Dissipates rapidly
Displaces oxygen
Nonconductive
Non-reactive
No residue
Halon: production was stopped in 1994
Halogenated Hydrocarbons
Halon replacement agents – “clean agents”
FM-110 FM-200
Inergen Haltron
May require up to 20 times as much as halon to provide an equal extinguishing capacity
Halogenated Hydrocarbons
Extinguisher Characteristics:
Size: 2.5 to 100 pounds
Discharge distance: 3-8 feet
Duration: 8-30 seconds
Method of expelling agent: stored pressure
Halogenated Hydrocarbons
Extinguishment principle: a chemical process that inhibits combustion
Class B and C fires: used in areas with sensitive electronic equipment
Halogenated Hydrocarbons
Advantages
High-expansion ratio
Needs no expellant
Nonconductive
Non-corrosive
No residue
Halon can be toxic and creates other toxic gases under fire conditions
Halon can be toxic and creates other toxic gases under fire conditions
FOAM EXTINGUISHERS
Extinguisher Characteristics:
Size: 2.5 gallons
Discharge distance: 20-25 feet
Duration: 50 seconds
Method of expelling agent: stored pressure
FOAM EXTINGUISHERSAgent Characteristics: Gas-filled bubbles Floats on flammable liquids Can be proportioned at
various concentrations
Extinguishment principle: smothering, some cooling
Class A and B fires
FOAM EXTINGUISHERS
Advantages
Limitations Not compatible with
some other agents Freezes Discharge distance Conducts electricity
Nontoxic Flow capabilities
Dry Powder Extinguishers
Extinguisher Characteristics:
Size: 30 to 350 pounds
Discharge distance: 4 - 6 feet
Duration: 20-30 seconds
Method of expelling agent: cartridge/stored pressure, shovel
Dry Powder Extinguishers
Designed for Class D fires
Agent Characteristics: Fine powder
Needs expellant force
No single agent is effective on all types of combustible metals
Dry Powder Extinguishers
No single agent is effective on all combustible metals
Limitations
Can become packed
Cannot interchange chemicals
Expensive
NA-X: for sodium and potassium MET-L-X: for sodium, potassium
and magnesium LITH-X: for sodium, lithium,
zirconium, and magnesium
Contains an agent in a cylinder with an expellant gas
Discharge handle and a gauge
Types of Extinguishers
Stored Pressure
Types of Extinguishers
Water FoamDry chemical HalonClean agents Dry powder
CO2
Stored Pressure
Cartridge Operated
Contain the explant gas in a separate cartridge from the agent
Does not have a pressure gauge
Types of Extinguishers
EXTINGUISHER OPERATIONEXTINGUISHER OPERATION
Pull pin
Aim nozzle
Squeeze handle
Sweep nozzle
Pull pin
Aim nozzle
Squeeze handle
Sweep nozzle
Check extinguisher before approaching
EXTINGUISHER SAFETYEXTINGUISHER SAFETY
Approach upwind
Don’t enter burn area
Don’t turn back on fire