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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