Special-Agent Fire Extinguishing Systems and Portable Extinguishers Flashcards
When would a special-agent fire extinguishing system need to be provided? (564)
Where standard automatic sprinkler systems are not the most effective way to address a particular fire risk. These locations may contain the following:
- Flammable and combustible liquids
- Water-reactive metals or chemicals
- Combustible metals that are flammable solids
- Food preparation equipment
- File storage or archives
- Electronic Information Technology (IT) Equipment
- Electrical transformers and switches
- High-value content such as museums
Identify the appropriate evaluation and testing methods for special-agent fire extinguishing systems. (594-597)
Dry-chemical (NFPA 17) & Wet-Chemical (NFPA 17A): Inspector shall evaluate the application methods, agents, components, and inspection and testing requirements. Dry storage containers <150 lbs must be hydrostatically tested every 12 years. A qualified individual/personnel must verify the system is maintained and serviced as required and have reviewed monthly:
- System parts in correct location
- Manual actuators unobstructed
- Tamper indicators and seals intact
- Maintenance tags in place, up to date
- Obvious damage noted
- Gauges within operational limits
- Equipment modifications/repairs noted
Clean-Agent Systems (NFPA 2001 and NFPA 12A for Halon 1301). Annual inspections by qualified personnel required. Quantity and pressure checked semiannually. Records on tests and inspections must be maintained and available for inspector to review. Inspector must know agents used in systems, components, inspection and testing requirements. Storage containers must meet DOT and TC req’ts and be hydrostatically tested every 5 years. Protected enclosure and local application hoses pressure tested annually. Verify integrity of space not compromised by penetrations.
Carbon Dioxide Systems. Only contractors licensed by manufacturer should perform maintenance and testing. Inspectors should be familiar with inspecting:
- physical damage to components
- excessive corrosion
- change in hazard
- enclosure integrity
- up to date records for required tests, inspections, and maintenance.
Agent cylinders checked semiannually, hydrostatic testing every 5 years.
Foam Systems. NFPA 25. Specially trained personnel required to inspect, service, and test. Inspectors should:
- check concentrate tank for signs of sludge, damage, deterioration
- verify inspections performed, documented
- Semiannually check valves and alarms
- Annually check foam concentrates, foam equipment, and foam proportioning systems. verify qualitative tests performed on concentrate to certify no contamination
Describe proper selection, distribution, inspection, and maintenance of portable fire extinguishers (597-602)
- Nature of hazard to be protected (light, ordinary, extra)
- Extinguisher size (based on hazard and max floor area)
- Travel distance (based on hazard class)
- Potential severity
- Personnel available
- Environmental conditions
- Anticipated adverse chemical reactions between agent and burning material
- Health and occupational safety concerns
- Inspection and service required to maintain extinguishers (monthly inspections recommended)
Define the different fire hazard classifications (565)
Class A - combustible solids. Involves ordinary, solid, combustible materials such as wood, cloth, paper, rubber, and many plastics
Class B - flammable liquids. Involves flammable and combustible liquids and gases such as gasoline, oil, lacquer, paint, mineral spirits, and alcohol.
Class C - electrical. Involves energized electrical equipment where the electrical nonconductivity of the extinguishing agent is of major importance; materials involved are either Class A (wiring insulation) or Class B (lubricants), and they can be extinguished once the equipment is de-energized
Class D - combustible metals. Involves combustible metals such as aluminum, magnesium, potassium, sodium, titanium, and zirconium (particularly in their powdered forms). May require special extinguishing agents or techniques.
Class K - kitchens. Involves oils and greases normally found in commercial cooking kitchen and food prep facilities using deep fryers. Through a process known as SAPONIFICATION, extinguishing agents turn fats and oils into a soapy foam that extinguishes a fire.
When are dry-chemical extinguishing systems used? (565)
Whenever rapid fire extinguishment is required and where reignition of burning materials is unlikely.
- Flammable liquid storage rooms
- Dip tanks
- Paint spray booths
- Exhaust duct systems
Name types of dry-chemical application methods (567)
Fixed System: agent storage tanks, expellant storage tanks, a heat-detection and activation system, piping, and nozzles.
- Local application
- Total Flooding
Handheld Hoseline: trained personnel apply dry chemical from hose stations connected to the agent and expellant storage containers. Fuel loading docks, aircraft hangars, outdoor aircraft parking areas, and flammable liquid storage rooms may require this method.
List the components in a dry-chemical extinguishing system (568)
~Storage container for agent and/or expellant gas. Range from 30 to 100 lbs, up to 2000 lbs. Must be in area -40deg F to 120deg F.
~Piping to carry agent and gas
~Nozzles
~Actuating Mechanism, responds to activation of fire detection system
Identify the common agents used in dry powder systems (569-571)
Dry powder systems are designed to extinguish Class D fires involving combustible metals. The agent must be carefully chosen for the hazard metal being protected.
NA-X: UL listed sodium carbonate-based with additives to enhance flow. Sodium, potassium, and sodium-potassium alloy fires. NOT for use on magnesium. Forms encasing crust causing oxygen deficiency. Can be in a fixed system, hand from pails, or portable extinguishers.
MET-L-X: sodium chloride (salt) based with flow additive. Magnesium, sodium, and potassium fires. Forms crust on burning metal. Applied first from fire extinguisher to control and then slowly to bury the fuel. Stable when stored in sealed containers, nonabrasive, and no known toxic effects.
LITH-X: graphite based, Conducts heat away from fuel after layer is applied. Developed for Lithium, but can be used on magnesium, zirconium, and sodium fires. Does not form a crust.
Identify the common agents used in dry chemical systems (567-568)
Sodium bicarbonate: Class B and C fires and has some effect on Class A surface fires. Chemically treated to be water-repellent and free-flowing. Successfully used on textile machinery.
Potassium bicarbonate: Aka Purple-K. Class B and C fires. Can extinguish twice the size of fire per pound as sodium bicarbonate. Chemically treated to be water-repellent and free-flowing.
Monoammonium phosphate: Class A, B, C. Multipurpose Dry-Chemical. Quickly extinguishes flaming combustion and melts to smother ordinary combustible materials. Can be corrosive to metals including extinguishing system nozzles, piping, and agent containers.
Differentiate between dry-chemical systems and wet-chemical systems (571)
The primary difference is the type of agent used.
Dry-chemical systems are used where wet would be ineffective. They smother (remove oxygen) or remove heat.
Wet-chemical systems are most effective in commercial cooking applications that produce grease-laden vapors. The wet chemical reacts with the oils and forms a soapy foam. Extinguishes fire by fuel removal, cooling, smothering, and flame inhibition.
What components are included in a clean-agent fire extinguishing system? (574)
Actuation devices, agent storage containers, piping, and discharge nozzles.
Why are CO2 systems dangerous to personnel? (575)
CO2 is an asphyxiant eliminating breathable oxygen from the atmosphere. The systems deliver a concentration that is lethal to humans.
Not as dangerous in a local application system delivered directly onto the fire as opposed to flooding, especially if outdoors or in a large building.
List the means of actuation for CO2 systems. (577)
Automatic operation: Initiated by a listed smoke or fire detection device. This triggers control valves on the CO2 supply.
Normal manual operation: Person manually operates a control device that puts system through cycle of operation including predischarge alarms.
Emergency manual operation: Used only when the other two modes fail. Causes system to discharge immediately without warning.
Explain how foam proportioners operate. (579-580, 583-584)
Foam proportioners introduce the correct amount of foam concentrate into a water stream which makes the foam solution before introduction of air. The nozzle or sprinkler aerates the solution into finished foam.
Balanced pressure proportioner: foam concentrate line connected to each fire pump discharge outlet or system riser. The foam pump provides pressure equal to the fire pump pressure. One of the most reliable methods. The same system can discharge foam and just water at the same time to different outlets.
Around-the-pump proportioner: Does not have a separate pump
Pressure proportioning tank system: Small amount of water goes into concentrate tank and releases foam by displacement
Couple water motor-pump proportioner:
Describe the letter symbols and pictorial symbols used for the different classes of fire (587)
Class A: Green Triangle, Trash Can & Log Fire
Class B: Red Square, Gas Tank Fire
Class C: Blue Circle, Plug and Outlet Fire
Class D: Yellow Star, Partial Gear Fire
Class K: Black Hexagon, Cooking Pan Fire
What should properly placed fire extinguishers exhibit? (592)
- Visible and marked with legible signage
- Not blocked by storage or equipment
- Near points of egress or ingress
- Near normal paths of travel
- Placed in proper physical environment for extinguisher (correct height, in a cabinet/recessed to protect extinguisher and people, correct temperature)
What are the standard mounting heights for a fire extinguisher? (593)
~ 40lbs or less, top no more than 5’ above floor
~ >40lbs, top no more than 3-1/2’ above floor
~ Clearance between bottom and floor should not be less than 4”
Describe the inspection requirements for dry-chemical systems (566)
~Review installation plans
~Review manufacturers’ specification sheets
~Inspect new installations
~Witness acceptance tests of those new installations
~Perform periodic inspections of existing systems
Dry-chemical (NFPA 17) & Wet-Chemical (NFPA 17A): Inspector shall evaluate the application methods, agents, components, and inspection and testing requirements. Dry storage containers <150 lbs must be hydrostatically tested every 12 years. A qualified individual/personnel must verify the system is maintained and serviced as required and have reviewed monthly:
- System parts in correct location
- Manual actuators unobstructed
- Tamper indicators and seals intact
- Maintenance tags in place, up to date
- Obvious damage noted
- Gauges within operational limits
- Equipment modifications/repairs noted
What is included in an inspection of wet-chemical systems?
Dry-chemical (NFPA 17) & Wet-Chemical (NFPA 17A): Inspector shall evaluate the application methods, agents, components, and inspection and testing requirements. Dry storage containers <150 lbs must be hydrostatically tested every 12 years. A qualified individual/personnel must verify the system is maintained and serviced as required and have reviewed monthly:
- System parts in correct location
- Manual actuators unobstructed
- Tamper indicators and seals intact
- Maintenance tags in place, up to date
- Obvious damage noted
- Gauges within operational limits
- Equipment modifications/repairs noted
List some of the items an inspector should verify when inspecting clean-agent systems
Clean-Agent Systems (NFPA 2001 and NFPA 12A for Halon 1301). Annual inspections by qualified personnel required. Quantity and pressure checked semiannually. Records on tests and inspections must be maintained and available for inspector to review. Inspector must know agents used in systems, components, inspection and testing requirements. Storage containers must meet DOT and TC req’ts and be hydrostatically tested every 5 years. Protected enclosure and local application hoses pressure tested annually. Verify integrity of space not compromised by penetrations.
What should inspectors look for when inspecting CO2 systems?
Carbon Dioxide Systems. Only contractors licensed by manufacturer should perform maintenance and testing. Inspectors should be familiar with inspecting:
- physical damage to components
- excessive corrosion
- change in hazard
- enclosure integrity
- up to date records for required tests, inspections, and maintenance.
Agent cylinders checked semiannually, hydrostatic testing every 5 years.
What items do inspectors need to verify when inspecting foam fire suppression systems?
Foam Systems. NFPA 25. Specially trained personnel required to inspect, service, and test. Inspectors should:
- check concentrate tank for signs of sludge, damage, deterioration
- verify inspections performed, documented
- Semiannually check valves and alarms
- Annually check foam concentrates, foam equipment, and foam proportioning systems. verify qualitative tests performed on concentrate to certify no contamination
What are the main factors that influence the proper distribution of portable fire extinguishers? (597)
- Nature of hazard to be protected (light, ordinary, extra)
- Extinguisher size
- Travel distance
- Potential severity
- Personnel available
- Environmental conditions
- Anticipated adverse chemical reactions between agent and burning material
- Health and occupational safety concerns
- Inspection and service required to maintain extinguishers
What should an inspector look for when inspecting portable fire extinguishers? (601-602)
- Proper location, visible, accessible
- Not obstructed
- Suitable for hazard being protected
- Check inspection tag to see if maintenance is due
- Examine nozzle or horn for obstructions
- Verify lock pins or tamper seals intact
- Signs of physical damage
- Fully charged with expellant and agent
- Proper operating pressure on gauge
- Check collar tag for current info and/or damage
- Required signage in place
- Legible operating instructions
Special-agent fire extinguishing systems are classified by the: (565)
A. type of occupancy.
B. type of fire they will extinguish.
C. type of agent used in the system.
D. amount of time it takes to expel the agent.
B
What type of special-agent fire extinguishing system is used when rapid fire extinguishment is required and where reignition is unlikely? (565)
A. Dry powder systems
B. Clean agent systems
C. Dry-chemical systems
D. Wet-chemical systems
C
What type of special-agent fire extinguishing system is used for combustible metal fires? (571)
A. Dry powder systems
B. Foam agent systems
C. Dry-chemical systems
D. Carbon dioxide systems
A
Which special-agent fire extinguishing system is most effective on fires in commercial cooking equipment that produces grease-laden vapors? (572)
A. Dry powder systems
B. Clean agent systems
C. Dry-chemical systems
D. Wet-chemical systems
D
What general category of fire extinguishing agents effectively leaves no residue? (574)
A. Dry powder systems
B. Clean agent systems
C. Dry-chemical systems
D. Carbon dioxide systems
B
Which special-agent fire extinguishing system is extremely cold and can freeze exposed skin? (577)
A. Dry powder systems
B. Clean agent systems
C. Dry-chemical systems
D. Carbon dioxide systems
D
Which system is used when water alone may not be an effective fire extinguishing agent? (580)
A. Foam system
B. Dry powder system
C. Dry-chemical system
D. Carbon dioxide system
A
