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Questions and Answers
What is the primary mechanism by which firefighting foam extinguishes a fire?
What is the primary mechanism by which firefighting foam extinguishes a fire?
- Forming a barrier that excludes oxygen from the combustion process. (correct)
- By chemically reacting with the fuel to neutralize it.
- By rapidly cooling the fuel to below its ignition point.
- Introducing a catalyst that inhibits the combustion reaction.
Why is water not always effective as an extinguishing agent, necessitating the use of firefighting foam in certain situations?
Why is water not always effective as an extinguishing agent, necessitating the use of firefighting foam in certain situations?
- Water alone does not work
- Water can exacerbate fires involving flammable liquids by causing them to spread. (correct)
- Water's high surface tension prevents it from spreading across burning liquid surfaces.
- Water is ineffective on Class A fires.
What is the purpose of the metering valve on an in-line foam eductor?
What is the purpose of the metering valve on an in-line foam eductor?
- To measure the output flow rate of the foam solution.
- To prevent backflow of foam concentrate into the water supply.
- To precisely control the amount of foam concentrate introduced into the water stream. (correct)
- To regulate the pressure of the water flowing through the Venturi.
How does the Venturi principle contribute to the function of an in-line foam eductor?
How does the Venturi principle contribute to the function of an in-line foam eductor?
What is the significance of the Akron Municipal Eductors featuring a removable metering dial?
What is the significance of the Akron Municipal Eductors featuring a removable metering dial?
What is the purpose of a foam shaper when assembling a foam fire stream system?
What is the purpose of a foam shaper when assembling a foam fire stream system?
In the typical assembly of a foam fire stream system, what component is attached directly to the pump discharge?
In the typical assembly of a foam fire stream system, what component is attached directly to the pump discharge?
Why is it important to use the correct foam application technique?
Why is it important to use the correct foam application technique?
Under what circumstances is the 'bank-down' method of foam application most suitable?
Under what circumstances is the 'bank-down' method of foam application most suitable?
When is the 'rain-down' method of foam application preferable to the 'roll-on' or 'bank-down' methods?
When is the 'rain-down' method of foam application preferable to the 'roll-on' or 'bank-down' methods?
How does the Quick Attack Foam Tube enhance firefighting capabilities when attached to a nozzle?
How does the Quick Attack Foam Tube enhance firefighting capabilities when attached to a nozzle?
What flow rate (in GPM) can the Foam Tube achieve when attached to a nozzle?
What flow rate (in GPM) can the Foam Tube achieve when attached to a nozzle?
What range of inlet pressure (in psi) are Akron Municipal Eductors rated to flow?
What range of inlet pressure (in psi) are Akron Municipal Eductors rated to flow?
What range of percentage settings do Akron Municipal Eductors feature on their metering dial?
What range of percentage settings do Akron Municipal Eductors feature on their metering dial?
What range of nozzle pressure (in psi) rating do Akron Municipal Eductors work efficiently with?
What range of nozzle pressure (in psi) rating do Akron Municipal Eductors work efficiently with?
How many lengths of 1 3/4" hose line should be attached to the eductor?
How many lengths of 1 3/4" hose line should be attached to the eductor?
What pump discharge pressure (in psi) must be maintained when assembling a foam fire stream system?
What pump discharge pressure (in psi) must be maintained when assembling a foam fire stream system?
Which type of extinguishing agent do PFD engine companies use?
Which type of extinguishing agent do PFD engine companies use?
For which classes of fires is foam intended?
For which classes of fires is foam intended?
According to the policy outlined, what is the overarching purpose of the manual chapter on basic foam operations?
According to the policy outlined, what is the overarching purpose of the manual chapter on basic foam operations?
What specific role does rank play in the implementation of the manual chapter on basic foam operations?
What specific role does rank play in the implementation of the manual chapter on basic foam operations?
In the context of in-line foam educators, what is the 'Venturi'?
In the context of in-line foam educators, what is the 'Venturi'?
What is the primary function of the 'reverse tapered section' in the discharge end of an in-line foam eductor?
What is the primary function of the 'reverse tapered section' in the discharge end of an in-line foam eductor?
In assembling a foam fire stream system, why is it crucial to avoid exceeding the recommended number of hose lengths connected to the eductor?
In assembling a foam fire stream system, why is it crucial to avoid exceeding the recommended number of hose lengths connected to the eductor?
Why is maintaining the correct pump discharge pressure (200 PSI) in a foam fire stream system critical for effective fire suppression?
Why is maintaining the correct pump discharge pressure (200 PSI) in a foam fire stream system critical for effective fire suppression?
Which of the following best illustrates the 'roll-on' method of foam application?
Which of the following best illustrates the 'roll-on' method of foam application?
In what scenario would the 'rain-down' method be the most effective foam application technique?
In what scenario would the 'rain-down' method be the most effective foam application technique?
How does the expansion ratio of AFFF (Aqueous Film Forming Foam) affect its firefighting capabilities?
How does the expansion ratio of AFFF (Aqueous Film Forming Foam) affect its firefighting capabilities?
What fundamental principle underlies the functionality of all three foam application techniques (roll-on, bank-down, rain-down)?
What fundamental principle underlies the functionality of all three foam application techniques (roll-on, bank-down, rain-down)?
Why does the Akron Municipal Eductor incorporate a large and easy-to-read metering dial?
Why does the Akron Municipal Eductor incorporate a large and easy-to-read metering dial?
What critical factor determines the selection of the most appropriate foam application technique for a given fire scenario?
What critical factor determines the selection of the most appropriate foam application technique for a given fire scenario?
Why are in-line foam eductors designed with specific inlet pressure ratings (e.g., 200 PSI) and nozzle pressure compatibility?
Why are in-line foam eductors designed with specific inlet pressure ratings (e.g., 200 PSI) and nozzle pressure compatibility?
Which of the following BEST describes the relationship between water, foam concentrate, and air in the formation of firefighting foam?
Which of the following BEST describes the relationship between water, foam concentrate, and air in the formation of firefighting foam?
How does the use of AFFF (Aqueous Film Forming Foam) enhance the effectiveness of firefighting operations on flammable liquid fires, compared to conventional foam concentrates?
How does the use of AFFF (Aqueous Film Forming Foam) enhance the effectiveness of firefighting operations on flammable liquid fires, compared to conventional foam concentrates?
When dealing with a three-dimensional flammable liquid fire (e.g., a running fuel spill from an elevated tank), which foam application technique would be MOST effective?
When dealing with a three-dimensional flammable liquid fire (e.g., a running fuel spill from an elevated tank), which foam application technique would be MOST effective?
What is the MOST critical factor to consider when determining the appropriate application rate of firefighting foam?
What is the MOST critical factor to consider when determining the appropriate application rate of firefighting foam?
In the context of foam fire streams, what does 'air aspiration' refer to, and why is it important?
In the context of foam fire streams, what does 'air aspiration' refer to, and why is it important?
What potential hazard is MOST directly associated with the improper application of firefighting foam, particularly in enclosed spaces?
What potential hazard is MOST directly associated with the improper application of firefighting foam, particularly in enclosed spaces?
Why is maintaining the correct ratio of foam concentrate to water crucial when using an in-line foam eductor?
Why is maintaining the correct ratio of foam concentrate to water crucial when using an in-line foam eductor?
In a scenario where firefighters encounter a large-scale spill fire with no nearby structures or objects suitable for banking foam, what is the MOST appropriate foam application method and why?
In a scenario where firefighters encounter a large-scale spill fire with no nearby structures or objects suitable for banking foam, what is the MOST appropriate foam application method and why?
When assembling a foam fire stream system with an in-line foam eductor, what is the potential consequence of exceeding the recommended number of hose lengths between the eductor and the nozzle?
When assembling a foam fire stream system with an in-line foam eductor, what is the potential consequence of exceeding the recommended number of hose lengths between the eductor and the nozzle?
What is the MOST appropriate way to handle a situation where the metering valve on an in-line foam eductor becomes clogged during foam operations?
What is the MOST appropriate way to handle a situation where the metering valve on an in-line foam eductor becomes clogged during foam operations?
How do the pressure ratings of the Akron Municipal Eductors affect their performance, and how does this influence their use in firefighting operations?
How do the pressure ratings of the Akron Municipal Eductors affect their performance, and how does this influence their use in firefighting operations?
Flashcards
What is Firefighting Foam?
What is Firefighting Foam?
Foam is an extinguishing agent formed by mixing a foam concentrate with water and aerating the solution for expansion. It is used for Class A and Class B fires.
What is an In-Line Foam Eductor?
What is an In-Line Foam Eductor?
An in-line foam eductor is a device that uses the Venturi principle to introduce foam concentrate into the water stream.
What is a Quick-Attack Foam Tube?
What is a Quick-Attack Foam Tube?
The Quick Attack Foam Tube is designed to easily and quickly latch on to various nozzles to provide air-aspirated foam capability.
How do you use the Roll-on Method?
How do you use the Roll-on Method?
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How do you use the Bank-Down Method?
How do you use the Bank-Down Method?
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How do you use the Rain-Down Method?
How do you use the Rain-Down Method?
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Study Notes
- This manual chapter provides general details regarding basic foam operations
- Each member is responsible for appropriate control as dictated by their rank in the execution of this chapter
General Information
- Foam is required under certain conditions, while water is not always effective for fire extinguishing
- Firefighting foam forms a blanket of foam on the surface of burning fuels
- Foam removes oxygen from the burning process and overtime the water from the solution is slowly released in turn cooling the fuel.
- Foam created by combining a foam concentrate with water and aerating the solution for expansion, is an extinguishing agent
- Foam is designed for Class A and Class B fires
- All PFD engine companies have an in-line foam eductor, foam shaper, and 3- to 5-gallon buckets of Universal Gold 1%/3% AFFF
Akron 125 GPM In-Line Foam Eductor
- The in-line foam educator uses the Venturi principle to introduce foam concentrate into the water stream
- Water goes in through a 1 ½ inch inlet of the educator, goes through a tapered section and out through a small orifice (the Venturi) into a larger chamber, resulting in a low-pressure area within the chamber
- A metering valve connects to an inlet to this chamber, and when open, allows the higher atmospheric pressure beyond the chamber to push the foam concentrate into the chamber
- The foam concentrate then mixes with the water coming out of the venturi and the mixture moves to the reverse tapered section in the discharge end of the eductor
- Akron Municipal Eductors have a large, easy-to-read, and removable metering dial with settings from 0% to 6%
- The Eductors can flow at 200 psi (14 bar) inlet pressure and work well with nozzles from 50 to 100 psi (3 to 7 bar)
Quick-Attack Foam Tube
- The Quick Attack Foam Tube quickly latches on to various nozzles bringing air-aspirated foam capability
- It has up to 12:1 expansion ration with AFFF
- When latched onto a nozzle, the Foam Tube flows up to 125 GPM
Assembling a Foam Fire Stream System
- Steps for assembling a system include:
- Attach the in-line foam eductor to the pump discharge
- Attach no more than 3 lengths of 1 3/4" hose line to the eductor
- Attach nozzle to the hose line
- Attach the foam shaper to the nozzle
- Pump discharge pressure must be 200 PSI
Foam Application Techniques
- Important techniques for applying foam are the roll-on, bank-down, and rain-down methods
Roll-On Method
- Direct the foam stream on the ground near the front edge of a burning liquid spill
- The foam then rolls across the surface of the fuel, it's application must be applied until it spreads across the entire surface and the fire is extinguished
Bank-Down Method
- This method can be used when there is an elevated structure near the burning fuel
- Direct the foam stream onto the structure and allow the foam to run down and onto the surface of the fuel
Rain-Down Method
- This method is used when roll-on and bank-down are impractical because of area size or no object to bank the stream
- Direct the stream into the air above the fire, allowing the foam to float down onto the surface
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