Essentials of Fire Fighting (4th Edition-FF1)-Chapter 5 ...
Essentials of Firefighting (4th Edition)
Chapter 5-Fire Extinguishers
FF1 Test Review
What is one of the MOST COMMON fire protection appliances used today?
▪ portable fire extinguishers
▪ found in fixed facilities & on fire apparatus
What TYPE of fires are extinguishers most useful on?
▪ incipient fires
What NFPA STANDARD provides additional info on rating, placement, & use of fire extinguishers?
▪ NFPA 10
What types of extinguishers should NOT be used by FF's?
▪ ones found in occupancies
What does NFPA 1901 require of pumping apparatus?
▪ that they carry 2 approved portable fire extinguishers with mounting brackets
▪ must be suitable for Class B & C fires
▪ minimum size of Dry Chemical extinguisher is 80 B:C
▪ required rating for CO2 is 10 B:C
▪ for water extinguishers, they must be 2 1/2 gallon or larger to be used on Class A fires
How and When should WATER TYPE extinguishers be protected against freezing?
▪ temps lower than 40oF
▪ protected by adding anti-freeze or storing in a warm area
What are PUMP TANK water extinguishers used for?
▪ small Class A fires only
▪ equipped with a double-acting pump
What is a STORED-PRESSURE water extinguisher?
▪ useful for small Class A fires & extinguishing confined hot spots during overhaul
▪ may be used for chimney flue fires
▪ water pressurized by compressed air or nitrogen
▪ Class A foam is sometimes added as a wetting agent for use in deep-seated fires, vehicle fires, & wildland fires
▪ Also called Air-Pressurized Water (APW) extinguishers
What are AFFF extinguishers?
▪ Aqueous Film Forming Foam
▪ For use on Class A & B fires
▪ Useful in combating fires or suppressing vapors on small fuel spills
▪ Has an air aspirating nozzle
▪ Expelled by compressed air or nitrogen
▪ Should not be applied directly onto fuel, gently rain down or deflect off an object
How does AFFF react with FUELS?
▪ foam floats on top of fuels that are lighter than water
▪ a vapor seal extinguishes the flame & prevents re-ignition
▪ foam is ineffective on flammable liquids that are water-soluble (polar solvents) such as alcohol and acetone
▪ not suitable for Class C & D fires or 3 dimensional fires such as fuel flowing down a hill
▪ MOST EFFECTIVE on static pools of flammable liquids
What is important about the USE of HALON extinguishers?
▪ halon causes ozone depletion
▪ the Montreal Protocol on Substances that Deplete the Ozone Layer called for a complete phase out of halogens by the year 2000
▪ the US stopped production of halogens in 1993
What is HALON?
▪ a generic term for halogenated hydrocarbons
▪ defined as a chemical compound that contains carbon plus 1 or more elements from the halogen series (flourine, chlorine, bromine, or iodine)
What are the 2 MOST COMMON Halon extinguishers?
▪ Halon 1211 - bromochlorodifluoromethane
▪ Halon 1301 - bromotrifluoromethane
What is important about HALOGENATED VAPORS?
▪ nonconductive and effective in extinguishing surface fires in flammable and combustible liquids and electrical equipment
▪ not effective on self-oxidizing fuels such as combustible metals, organic peroxides, and metal hydrides
▪ long been used for protection of internal combustion engines
▪ primary modern-day application is to protect sensitive electronic equipment
What is HALON 1211 mainly used for?
▪ on Class B & C fires
▪ extinguishers greater than 9 lbs. In capacity, also have a Class A rating of 1-A to 4-A
▪ larger wheeled units may weigh up to 150 lbs.
How is HALON 1211 stored and used?
▪ stored as liquified compressed gas & nitrogen is used to boost discharge pressure
▪ discharged in a clear liquid stream giving greater reach than gas extinguishers
▪ stream may be affected by wind
What are some features of HALON 1301 extinguishers?
▪ not used by itself because gas discharge is nearly invisible
▪ highly susceptible to wind
▪ agent's volatility allows it to disperse faster that Halon
▪ it is the agent of choice in total flooding systems using halogenated agents
What are some features of CARBON DIOXIDE extinguishers?
▪ found in handheld and wheeled units
▪ effective on Class B & C fires
▪ discharge is in gas form and has a limited reach
▪ DO NOT require freeze protection
▪ Stored under its own pressure as a liquified compressed gas
▪ Discharged through a plastic or rubber horn at end of short tube or hose
▪ Discharge usually accompanied by ice crystals
▪ Displaces oxygen and smothers fire
▪ Re-ignition is always possible due to NO vapor-suppressing film produced
Where are WHEELED CO2 units usually found?
▪ in airports or industrial facilities
▪ hose may be up to 15 feet and MUST be unwound before use
What are some features of DRY CHEMICAL extinguishers?
▪ for use either on Class A, B, & C fires and/or Class B & C fires
▪ agents are mixed with small amounts of additives to keep agents moist to prevent caking
▪ non-toxic, yet cloud of chemicals may reduce visibility & create respiratory problems
▪ some dry chemicals are compatible with foam but others degrade foam
▪ agent should be applied intermittently on any smoldering hot spots
▪ many dry chemicals are corrosive to metal
What are the 2 basic TYPES of DRY CHEMICAL extinguishers?
▪ regular B:C rated and multipurpose A:B:C rated
What are some of the chemicals used in DRY CHEMICAL extinguishers?
▪ sodium bicarbonate
▪ potassium bicarbonate
▪ urea-potassium bicarbonate
▪ potassium chloride
▪ monoammonium phosphate
What are DRY POWDER chemicals used for?
▪ ONLY Class D fires
What are the 2 TYPES of HANDHELD Dry Chemical extinguishers?
▪ Stored-Pressure - similar to air-pressurized water extinguisher and have a constant pressure of about 200 psi
▪ Cartridge-Operated - employ a pressure cartridge connected to the agent tank (not pressurized until plunger is pushed to release gas from the cartridge)
▪ Both types use nitrogen or carbon dioxide as the pressurizing gas
▪ Cartridge type uses CO2 unless subjected to freezing temps, dry nitrogen is used in freezing temps
What are some features of WHEELED Dry Chemical units?
▪ ones rated for Class A, B, & C depending on the type of chemical in the unit
▪ extinguishing agent is in one cylinder and the pressurizing gas in another cylinder
▪ hose must be unwound before use (removing hose after charged is difficult)
▪ powder can pack in sharp bend of hose
▪ pressurizing gas should be given a few seconds before opening nozzle
▪ top of extinguisher should be pointed away from FF when pressurizing
▪ significant nozzle reaction should be accounted for
How are DRY POWDERS applied?
▪ some with portable extinguishers and some with scoops and shovels
▪ no single agent will control or extinguish all combustible metal fires
▪ must be applied in sufficient depth to completely cover area by creating a smothering blanket
How must burning metal on a combustible surface be EXTINGUISHED?
▪ first cover with a powder, then a 1-2-inch layer of powder should be spread nearby and burning metal shoveled onto this layer
What is a CLASS A RATING?
▪ rated from 1-A through 40-A
▪ primarily based on the amount of extinguishing agent and duration and range of discharge
▪ for a 1-A rating, 1 1/4 gallons of water is required
▪ a 2-A rating, must have TWICE the amount of extinguishing agent (2 1/2 gallons)
What is a CLASS B RATING?
▪ rated from 1-B through 640-B
▪ based on the approximate square foot area of a flammable liquid that a NON-EXPERT operator can extinguish
▪ expected to extinguish 1 square foot for each numerical rating
What is a CLASS C RATING?
▪ receive only a letter rating
▪ fires in Class C are essentially Class A or B fires once electricity is taken away
▪ agents are tested for non-conductivity
What is a CLASS D RATING?
▪ vary with the type of combustible metal
▪ factors include: reactions between metal and agent, toxicity of agent, toxicity of fumes produced, and time allowed to let metal burn out -vs- time to extinguish it
▪ details of instruction should be printed on extinguisher face plate
▪ no numerical rating is given and cannot be given a multi-purpose rating
What are MULTIPLE MARKINGS?
▪ Suitable for more than one type of fire
▪ three MOST COMMON combinations are Class A-B-C, Class A-B, and Class B-C
▪ any extinguisher NOT properly marked should NOT be used
What are the 2 SYSTEMS of LABELING extinguishers?
▪ geometric shapes: Class A = Green Triangle with A, Class B = Red Square with B,
▪ Class C = Blue Circle with C, & Class D = Gold Star with D
▪ NFPA pictographs - depicting the type of fires the extinguisher can be used on and also shows fires which it cannot be used on
What are the FACTORS for the proper selection of a fire extinguisher?
▪ classification of burning fuel
▪ rating of extinguisher
▪ hazards to be protected
▪ severity of fire
▪ atmospheric conditions
▪ availability of trained personnel
▪ ease of handling
▪ any life hazard or operational concerns
What is the BEST extinguisher for sensitive electronic equipment?
▪ halon or carbon dioxide
What things should be CHECKED before use?
▪ external condition - no apparent damage
▪ Hose/Nozzle - in place
▪ Weight - feels as though it contains agent
▪ Pressure Gauge - in operable range
How should fires be APPROACHED with extinguishers?
▪ from the windward side
▪ must be sure extinguishing agent reaches the fire
▪ radiant heat may prevent getting close enough for agent to reach fire
▪ winds may also affect or limit reach of agent
▪ discharging agent directly onto fire can sometimes scatter lightweight solid fuels or penetrate surface of liquid fuels
▪ apply from a point where it reaches but does not disturb the fuel
▪ after fire is knocked down, move in closer for final extinguishment
How should FINAL EXTINGUISHMENT be accomplished?
▪ when reduced to smoldering phase, overhaul with appropriate tool and use charged hoseline to complete extinguishment
▪ on fires in liquid fuels, apply appropriate foam or simultaneously attack with more than one extinguisher
What does an extinguisher on its SIDE mean?
▪ signals an empty cylinder
▪ reduces the chance of a FF trying to approach a fire with an empty extinguisher
Who is responsible for SERVICING fire extinguishers?
▪ property owner or building occupant
What should fire inspectors include in their BUILDING INSPECTION and pre-incident planning?
▪ fire extinguisher inspections
What 3 important FACTORS determine the VALUE of a fire extinguisher?
▪ serviceability, accessibility, and user's ability to operate it
What NFPA STANDARD explains the procedures for hydrostatic testing of extinguishers?
▪ NFPA 10
Where should extinguisher TEST RESULTS be recorded?
▪ on the extinguisher
▪ hydrostatic test results on low-pressure and high-pressure cylinders are recorded differently
What are the PROCEDURES for fire extinguisher inspections?
▪ ensure proper location and accessibility
▪ inspect discharge nozzle or horn for obstructions
▪ check for cracks, dirt, and grease accumulation
▪ operating instructions on nameplate legible
▪ lock pins and tamper seals secure
▪ full of agent and fully pressurized (check gauge, weigh extinguisher, or inspect agent level)
▪ extinguishers deficient on weight by 10% should be removed from service and replaced
▪ check inspection tag for last inspection, maintenance, or re-charging
▪ examine condition of hose and fittings
What should REPLACEMENT extinguishers be?
▪ of equal or greater rating
What should be done with LEAKING, CORRODED, or DAMAGED cylinders?
▪ discarded or returned to manufacturer for repair
▪ never attempt to repair a cylinder or shell
What if an extinguisher shows SLIGHT DAMAGE or CORROSION?
▪ have it hydrostatically tested by manufacturer or qualified testing agency
When were INVERTED-TYPE tanks no longer manufactured?
▪ American manufacturers stopped in 1969
▪ Included soda-type, foam, internal cartridge-operated water and loaded stream, and internal cartridge dry chemical extinguishers
▪ Also included cylinders made of copper or brass
What TOXIC CHEMICALS used in extinguishers were discontinued due to OSHA 29 CFR 1910.157, subpart L?
▪ carbon tetrachloride and chlorobromomethane
▪ removed from service by January, 1982
DON'T FORGET TO STUDY THE PICTURES!!!
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