Presentation on theme: "Chapter 6 Portable Fire Extinguishers. 6–2 Chapter 6 Lesson Goal After completing this lesson, the student shall be able to operate portable fire extinguishers."— Presentation transcript:
Chapter 6 Portable Fire Extinguishers
6–2 Chapter 6 Lesson Goal After completing this lesson, the student shall be able to operate portable fire extinguishers effectively & safely
6–3 Portable Fire Extinguishers Intended for incipient fires Quicker to deploy than hoselines Found in most facilities, i.e. homes, businesses Require little training to use
6–4 Portable Fire Extinguishers Most common fire protection device Most are re-chargeable FFs should not rely on privately–owned fire extinguishers
6–5 Fire Extinguishment Methods Smothering Cooling Chain breaking Saponification
6–6 DISCUSSION QUESTION Has anyone in the class ever used a portable fire extinguisher to extinguish a fire?
6–7 Portable Extinguisher Discharge Mechanisms All use some form of pressure: Manual pump Stored pressure Pressure cartridge Cylinder (wheeled units)
6–8 Fire Classifications Fire extinguishers classified & rated according to their intended use Class A fires Involve ordinary combustibles Easily extinguished with water, water-based agents (foam), dry chemicals Water most common agent used by fire service (Continued)
6–9 Fire Classifications Class B fires Involve flammable/ combustible liquids, gases, greases Special fire hazards; should not be extinguished until fuel gas shut off Special-hazard fires get larger as fuel volume increases Extinguishing agents include carbon dioxide, dry chemical, Class B foam (Continued)
6–10 Fire Classifications Class C fires Involve Class A or B fires created by electrical energy Do not use water or water-based agents until electricity is shut off Recommended method is to turn off or disconnect electrical power before using appropriate extinguisher (Continued)
6–11 Fire Classifications Class D fires Involve combustible metals, alloys Can be identified by bright white sparks & emissions from fire process Class D, dry powder extinguishers work best (Continued)
6–12 DISCUSSION QUESTION Why should water-based agents not be used on Class D fires?
6–13 Fire Classifications Class K fires Involve combustible cooking oils Examples are vegetable fats that burn at extremely high temperatures Most fuels found in commercial kitchens; can also be found in private homes Wet chemicals used in extinguishing systems
6–14 Stored-Pressure Water Extinguishers Air-pressurized water extinguishers or pressurized water extinguishers Useful for all types of small Class A fires (Continued)
6–15 Stored-Pressure Water Extinguishers Often used for extinguishing hot spots Operation Water stored in tank w/air or nitrogen Gauge shows pressurization Pressure forces water up tube, out hose Class A foam concentrate sometimes added
6–16 Stored-Pressure Water Extinguishers Affected by freezing weather Loaded stream extinguishers have an anti-freeze added Not suitable for Class C & D fires Maximum size is 2A
6–17 Wet Chemical Stored-Pressure Extinguishers Specifically designed to control/extinguish Class K fires in deep fryers Contain special potassium-based alkaline agent to cool/suppress fires in unsaturated cooking oils Courtesy of Ansul Corp.
6–18 Aqueous Film Forming Foam (AFFF) Extinguishers Suitable for Class A, Class B fires Fires/vapors from small liquid fuel spills Different from stored-pressure water extinguishers Tank contains specified amount of AFFF concentrate mixed with water Air-aspirating nozzle aerates solution (Continued)
6–19 Aqueous Film Forming Foam (AFFF) Extinguishers Water/AFFF solution expelled by compressed air or nitrogen To prevent disturbance of foam blanket, do not apply directly onto fuel; allow to rain onto surface/deflect off object (Continued)
6–20 Aqueous Film Forming Foam (AFFF) Extinguishers When AFFF/water mixed, finished foam floats on fuels lighter than water Vapor seal created by film of water extinguishes flame, prevents reignition (Continued)
6–21 Aqueous Film Forming Foam (AFFF) Extinguishers Foam has good wetting, penetrating properties on Class A fuels; ineffective on polar solvents Not suitable for fires in Class C, D fuels Not suitable for flowing fuels Most effective on static pools of flammable liquids
6–22 Clean Agent Extinguishers Designed to replace halons, & use clean agents that discharge as rapidly evaporating liquids that leaves no residue Nonconductive so can be used on Class C Approved by U.S. EPA Halon replacements work by inhibiting the chemical chain reaction
6–23 Carbon Dioxide (CO 2 ) Extinguishers Found as both handheld/wheeled units Most effective in Class B, C fires Leaves no residue Have limited reach; gas can be dispersed by wind (Continued) Courtesy of Ansul Corp.
6–24 Carbon Dioxide (CO 2 ) Extinguishers Carbon dioxide stored under its own pressure as liquefied gas ready for release at any time Wheeled units similar to handheld except they are bigger Courtesy of Badger Fire Protection.
6–25 Carbon Dioxide (CO 2 ) Extinguishers Hazards Do not touch horn during discharge Static electricity shock Cold injuries In confined spaces it displaces oxygen
Dry Chemical Extinguishers For Class A-B-C fires and/or Class B-C fires; dry powder used on Class D only Two types: Cartridge operated Stored pressure 6–26 (Continued) Courtesy of Ansul Corp.
6–27 Dry Chemical Extinguishers Puts out fire by breaking chemical chain reaction Two basic chemicals: Regular B:C-rated Multipurpose and A:B:C-rated Courtesy of Ansul Corp.
6–28 Dry Chemical Extinguishers AgentCommon NamesClass of Fire Sodium bicarbonateRegularB&C Potassium bicarbonate Purple KB&C Potassium chlorideSuper KB&C Monoammonium phosphate Multi-purposeABC
Wheeled Fire Extinguishers Large units mounted on wheeled carriages Typically contain 150 to 350 lbs of extinguishing agent Indoor use requires wide doorways & aisles 6–29
Wheeled Fire Extinguishers Long delivery hoses allow operators to attack fire from multiple sides Usually pressurized by separate cylinders Installed in special hazard areas 6–30
6–31 Controlling/Extinguishing Metal Fires Special extinguishing agents, application techniques developed to control/extinguish metal fires No single agent controls/extinguishes fires in all combustible metals Agent is usually a powder Note: Dry powder & dry chemical not the same thing (Continued)
6–32 Controlling/Extinguishing Metal Fires Some powdered agents applied with portable extinguishers, others with shovel or scoop Appropriate application technique described in manufacturers technical sales literature (Continued)
6–33 Controlling/Extinguishing Metal Fires Portable extinguishers for Class D come in both handheld & wheeled units (Continued) Courtesy of Amerex Corp.
6–34 Controlling/Extinguishing Metal Fires Powder must be applied in sufficient depth to completely cover burning area to create smothering blanket (Continued)
6–35 Controlling/Extinguishing Metal Fires If small amount of burning metal on combustible surface, fire should be covered with powder 1 to 2 inch (25 to 50 mm) layer spread nearby, burning metal shoveled onto layer After extinguishment, material left undisturbed until cooled
6–36 Portable Extinguisher Rating System Portable extinguishers classified according to types of fire they extinguish Class A, B also rated according to performance capability System based on tests by UL, ULC
6–37 Classifications Class A From 1-A through 40-A Class B From 1-B through 640-B Class C No tests Class D Test fires vary Class K Recognized by UL, ULC since 1996
6–38 Classifications A Rating: Based on 1.25 gallons (5 L) of water 2A = 2.5 gallon (10 L) B Rating: Based on square foot or square meter 20B = 20 sq ft (1.8 sq m) C Rating: Bases on electrical shock hazard (no shock, its a Class C)
6–39 Classifications D Rating: Used for metals only, no rating Must be specific to types of metal K Rating: Used for hot cooking oil application (deep fryers)
6–40 Multiple Markings Extinguishers for more than one class of fire identified by combinations of A, B, and/or C or symbols for each class Most common are A-B-C, A-B, B-C All must be labeled appropriately Unlisted units should not be used Ratings for each class are independent
6–41 Identification Two Ways Geometric shapes of specific colors with class letter shown within shape NFPA 10 recommended Uses pictographs to make selection easier; shows types of fires on which extinguishers should not be used
Classification of Fire Extinguishers K COOKING OILS COOKING FATS 6–42
Classification of Fire Extinguishers Red slash across pictograph means Do Not Use Use of the fire extinguisher on this type of fire could be dangerous 6–43
6–44 Extinguisher Selection Factors Classification of burning fuel Rating of extinguisher Hazards to be protected Size/intensity of fire (Continued)
6–45 Extinguisher Selection Factors Outside conditions Availability of trained personnel Ease of handling extinguisher Life hazard/operational concerns
6–46 Extinguisher Selection Considerations Select those that minimize risk to life/ property & are effective in extinguishing the fire type Dry chemical extinguishers should not be selected for use in areas where highly sensitive computer equipment is located
6–47 Extinguisher Check Immediately before use External condition Hose/nozzle Weight Pressure gauge After selecting size/type for situation, approach fire from upwind side
6–48 DISCUSSION QUESTION Why should you always have an escape route?
6–49 Fire Extinguisher Operation Most extinguishers operate in a similar manner Pick up extinguisher by handles, carry to point of application (Continued)
6–50 Fire Extinguisher Operation Once in position, use PASS method P Pull the pin A Aim the nozzle at the base of the fire S Squeeze handles together S Sweep nozzle back & forth (Continued)
6–51 Fire Extinguisher Operation Be sure agent reaches fire Apply agent from point where stream reaches but does not disturb fuel After fire knocked down, move closer for final extinguishment (Continued)
6–52 Fire Extinguisher Operation If extinguishment not achieved after entire extinguisher discharged, withdraw/reassess If fire is in solid fuel reduced to smoldering phase, may be overhauled using appropriate tool (Continued)
6–53 Fire Extinguisher Operation If fire in liquid fuel, it may be necessary to apply foam through hoseline or attack with more than one extinguisher If more than one extinguisher used, work together & maintain constant awareness
6–54 Fire Extinguisher Inspections NFPA 10 & most fire codes require portable extinguishers inspected at least once/year Verify that extinguishers Are in designated locations Not tampered with or activated No obvious damage/other condition (Continued)
6–55 Fire Extinguisher Inspections Servicing responsibility of property owner/building occupant FFs should include inspections in building inspection program (Continued)
6–56 Fire Extinguisher Inspections Three factors determine usefulness of fire extinguishers Serviceability Accessibility Simplicity of operation NFPA 10 describes procedures for hydrostatic testing of cylinders
6–57 Parts of Fire Extinguisher Inspections Ensure extinguisher in proper location/accessible Inspect discharge nozzle Inspect extinguisher shell Check for legible operating instructions on nameplate INACCESSIBLE (Continued)
6–58 Parts of Fire Extinguisher Inspections Check locking pin, tamper seal Determine whether full of agent, fully pressurized Check for date of previous inspection Examine condition of hose/fittings If any items deficient, remove from service
6–59 Damaged Fire Extinguishers Can fail at any time; could result in serious injury Leaking, corroded, otherwise damaged shells/cylinders should be discarded or returned to manufacturer for repair (Continued)
6–60 DISCUSSION QUESTION How should a defective fire extinguisher be repaired?
6–61 Damaged Fire Extinguishers Only slight damage/corrosion & uncertain whether safe Should be hydrostatically tested If allowed by SOP, leaking hoses, gaskets, nozzles, & loose labels can be replaced by FFs
6–62 Obsolete Portable Fire Extinguishers Since 1969 Manufacturers stopped making inverting-type extinguishers All extinguishers are carried upright Manufacturing of extinguishers made of copper or brass with cylinders soft soldered or riveted together discontinued (Continued)
6–63 Halon Fire Extinguishers Included in Montreal Protocol Damages the ozone World stopped producing halogens at end of 1993 By 2010 all halons, fixed or otherwise, are to be removed
6–64 Summary In many cases, fire extinguishers can control or extinguish small fires in less time than it takes to deploy a hoseline (Continued)
6–65 Summary Even though portable fire extinguishers may be found in many of the homes, apartments, & businesses that must be entered to extinguish fire, FFs should only rely on those carried on the fire apparatus. (Continued)
6–66 Summary To use fire extinguishers safely & effectively, FFs must know capabilities & limitations of the extinguisher & their own capabilities & limitations as well as the proper techniques for their application
6–67 Skills Operate a stored pressure water extinguisher Operate a dry chemical (ABC) extinguisher Operate a carbon dioxide (CO 2 ) extinguisher Clean, service & place a portable fire extinguisher back in service. (Skill Sheet FF-I-101)(Skill Sheet FF-I-101) Operate a dry chemical wheeled unit (Exercise 2)(Exercise 2)