I-C-04 Foam Operations 06/22/2021

Questions and Answers

What is the primary use of Class B foam?

To enhance the efficacy of water in firefighting

To extinguish fires involving combustible liquids (correct)

To suppress wildland fires

To create a polymeric membrane for vapor suppression

Which foam type is NOT allowed during training evolutions?

Alcohol Resistant Aqueous Film Forming Foam (AR-AFFF)

Class B AR-AFFF

Class A FireAde (correct)

Regular Aqueous Film Forming Foam (AFFF)

How much water is needed to simulate finished foam using the suggested mixture?

10 gallons

7 gallons

5 gallons (correct)

3 gallons

What is a requirement for combining AR-AFFF with regular AFFF?

They should never be combined Signup and view all the answers

What properties are characteristic of Aqueous Film Forming Foam (AFFF)?

It has self-healing properties and produces a bubble blanket Signup and view all the answers

What is the minimum percentage of AFFF that should be utilized in operations?

3%-6% Signup and view all the answers

Which foam is indicated for use with polar solvent-based fuels?

Alcohol Resistant Aqueous Film Forming Foam (AR-AFFF) Signup and view all the answers

What does the batch mixing process involve?

Adding foam concentrate to a tank to create a specific foam solution Signup and view all the answers

What is the maximum distance from a hydrant within which an ARFF vehicle can directly receive water without additional apparatus?

300 feet Signup and view all the answers

Which component does the ARFF foam supply resource pump directly to during operation?

The rear aerial intake Signup and view all the answers

Who is responsible for operating the aerial master stream during the firefighting operation?

The aerial D/O Signup and view all the answers

What type of nozzle should be attached to the aerial for effective operation?

Master stream fog nozzle Signup and view all the answers

Which hose size is required for supplying foam to the rear aerial inlet?

5 inch Signup and view all the answers

What is the primary function of Class A foam in firefighting?

To break down water's surface tension for greater penetration Signup and view all the answers

Which statement regarding the application of Class B foam is true?

It separates the fuel from air and cools the fuel. Signup and view all the answers

At what percentage should Class A foam be proportioned for effective firefighting?

0.5% - 1.0% Signup and view all the answers

What should be avoided when using Class B foam according to the provided procedures?

Positioning apparatus downwind from the fire Signup and view all the answers

What is the potential consequence of mixing different types of foam concentrates?

Gelling and restriction of flow through systems Signup and view all the answers

What is the primary role of the Driver/Operator (D/O) during foam operations?

To ensure the foam tank is full with the appropriate foam concentrate Signup and view all the answers

What does the Critical Flow Rate refer to in fire suppression?

The minimum gpm of foam required to extinguish a fire Signup and view all the answers

Under what condition should foam operations be delayed?

If there are insufficient foam resources available Signup and view all the answers

How should liquid soap be utilized in firefighting?

As a crude but effective version of Class A foam Signup and view all the answers

Which type of foam is typically used for alcohol-related fires?

Alcohol resistant aqueous film forming foam (ARAFFF) Signup and view all the answers

What is the foam solution made of?

Foam concentrate, water, and air Signup and view all the answers

Which position is responsible for overseeing foam operations?

#1 - Officer-in-Charge Signup and view all the answers

When utilizing a portable standpipe, what is crucial to ensure?

That the foam line setup occurs within the building Signup and view all the answers

What causes foam blankets to lose effectiveness on boiling fuel?

Continuous application is necessary to cool the fuel Signup and view all the answers

What is the maximum recommended length of 1-¾” hose to avoid significant foam quality reduction?

200 feet Signup and view all the answers

To ensure proper foam proportioning, what is the effect of pumping less than 200 psi to the eductor inlet?

It causes more foam to be educted. Signup and view all the answers

For extinguishing hydrocarbon spills, what initial proportion should be set on the proportioner?

3% Signup and view all the answers

What is the critical flow rate formula for hydrocarbons?

GPM = A/10 Signup and view all the answers

The Elkhart Chief 4000-14 fog nozzle operates at what flow rate?

125 gpm Signup and view all the answers

Why must ARFF units be supplied with a continuous supply of water?

To achieve their full delivery capacity. Signup and view all the answers

What happens to the foam stream when using lower-rated fog nozzles with the eductor?

It reduces proportioning rates. Signup and view all the answers

What should be done if lower explosive limits (LEL) are detected when using foam blankets?

Reapply the foam blankets. Signup and view all the answers

What is the recommended height limit for the foam concentrate level to the eductor?

6 feet Signup and view all the answers

What is the effect of using ethanol additives in a hydrocarbon during foam application?

Flow foam as specified for polar solvents. Signup and view all the answers

Which of the following units has different eductors and foam nozzles than the rest of Operations?

HazMat suppression units Signup and view all the answers

What is the flow time range for foam application during firefighting?

15 – 60 minutes Signup and view all the answers

Which capability is unique to ARFF apparatus compared to other units?

Non-alcohol resistant AFFF Signup and view all the answers

What is the critical flow rate formula for polar solvents?

GPM = A/5 Signup and view all the answers

How many pails of foam should be available per 1-¾” foam line when extinguishing an ignited polar solvent?

16 pails Signup and view all the answers

In the event of batch mixing, what percentage should be used to calculate the required concentrate gallons in a 500-gallon tank for 3% foam?

0.03 Signup and view all the answers

What is the consequence of not properly flushing the system after using AFFF foam during a fire operation?

It may lead to corrosion and premature wear. Signup and view all the answers

Which foam application method aims to spread the foam blanket by directing the stream at the ground from the perimeter of the spill?

Roll-on method Signup and view all the answers

What is the maximum length of 1-¾” foam line that can be used without additional hose?

200 feet Signup and view all the answers

Which of the following is a common reason for poor-quality foam blankets?

Clogged pick-up tube Signup and view all the answers

What is the recommended method to minimize trip hazards when walking on foam blankets?

Shuffling feet while walking Signup and view all the answers

When performing a batch mix for 6% foam in a 750-gallon tank, how many gallons of concentrate are needed?

45 gallons Signup and view all the answers

What must be the eductor pressure for effective foam application?

200 psi Signup and view all the answers

What is a critical factor to check prior to inserting the pick-up tube into the open containers?

Proper percentage setting on the eductor Signup and view all the answers

Which foam application method gently applies foam over the spill from above aiming at a 30-degree angle?

Rain-drop method Signup and view all the answers

What immediate action must be performed following a batch mix operation with foam?

Flush the complete system Signup and view all the answers

Which method requires the nozzle to be aimed parallel to the surface of the fuel without plunging into it?

Seat-of-the-fire method Signup and view all the answers

What should be the maximum distance from the nozzle to the eductor when using the AWG S4/M4 low/medium expansion foam nozzle?

200 feet Signup and view all the answers

How can improperly working eductors be temporarily repaired?

By tapping with a rubber mallet Signup and view all the answers

What is the recommended solution if air leaks occur around the pick-up tube attachment to the eductor?

Replace plastic clamps with metal ones Signup and view all the answers

What is the priority action after every use of an eductor assembly?

Wash the ball check valve with warm water Signup and view all the answers

At what pressure must the eductor backflush button not be forced?

75 psi Signup and view all the answers

What should be confirmed before inserting the pick-up tube into the foam containers?

The aerial discharge valve is closed Signup and view all the answers

Which component is replaced with a 2-½” x 1-½” reducer during the aerial foam evolution?

The aerial master stream nozzle Signup and view all the answers

What is a temporary fix for a foam blanket that appears watery during application?

Increase the proportioning rate Signup and view all the answers

What flow rate is the Chief model #4000-14 fog nozzle rated for?

125 gpm Signup and view all the answers

What action should be taken if the pump panel is receiving water from a pressurized source during flushing?

Gate down or disengage the pump Signup and view all the answers

Which of the following must be done to the hoseline during the flushing process?

Flush with water until no foam is present Signup and view all the answers

Which accessory should be used when connecting the in-line foam eductor to the pump panel for a 250 GPM flow rate?

5” storz x 2-½” female adapter Signup and view all the answers

How should the pressure at the eductor be monitored during the flushing process?

By ensuring it is below 75 psi Signup and view all the answers

Study Notes

Foam Types and Usage

Class A foam is effective for ordinary combustibles, enhancing water penetration for fires like tire, vehicle, and wildland fires.
Class B foam extinguishes flammable liquid fires by vapor suppression and cooling.
Foam application training must exclude Class A FireAde and Class B AR-AFFF due to health concerns.
Finished foam can be made from a mix of five gallons of water and three cups of car wash.

Foam Definitions

Alcohol Resistant Aqueous Film Forming Foam (AR-AFFF) is used with polar solvents at a concentration of 6%.
Aqueous Film Forming Foam (AFFF) is a detergent-based foam compatible with dry chemical agents, known for rapid extinction and self-healing characteristics.
Finished foam comprises a mixture of foam concentrate, water, and air.

Operational Procedures for Class A Foam

Utilize Class A foam for better penetration and quicker extinguishment over plain water on various fire types.
Ensure apparatus foam tanks are filled with Class A foam concentrate; do not mix with Class B foam.
Class A foam should be proportioned between 0.5% and 1.0%.
Liquid soap can act as a basic substitute for Class A foam.

Class B Foam Application

Class B foam works by separating fuel from air, cooling it, and suppressing vapors.
Majority of foam generation occurs through induction or batch mixing.
Operations typically employ 3% to 6% AR-AFFF sourced in 5-gallon buckets.
Proper foam volume must be available before beginning a foam operation; prioritize exposure protection otherwise.

Equipment and Resources

Onboard Class B systems must not mix Class A foam; familiarize with each unit's system.
Suppression units are equipped with specific foam generating equipment, like Elkhart and TFT in-line eductors.
ARFF units focus on regular AFFF, carrying high foam output capacities with various supplier options available.

Application Hydraulics and Techniques

An in-line foam eductor requires a pump pressure of 200 psi at its inlet, adjusted for hose lengths and elevation.
Maintain foam concentrate at a maximum height of 6 feet from the eductor.
For ignited spills, proper flow rates and durations are essential, with different formulas depending on fuel types (hydrocarbon vs. polar solvent).

Foam Application Methods

Employ methods such as roll-on, bank-down, rain-drop, and seat-of-the-fire for effective foam application.
Minimize walking on foam blankets and use careful foot placement if necessary.

Common Issues and Solutions

Avoid foam quality issues by ensuring proper nozzle operation, correct eductor pressure, and unclogged systems.
Address excessive hose length by limiting configurations to standard lengths; maintain the integrity of foam lines to ensure effective application.### Eductor Ball Check Valve Maintenance
Shut down pump discharge gates when possible to prevent damage during maintenance.
For a stuck eductor ball, gently tap with a rubber mallet or release the ball using a screwdriver.
Replace plastic clamps on the pick-up tube attachment with metal ones to prevent air leaks.
After each use, disassemble the eductor assembly and wash the ball check valve with warm water to avoid sticking.

Foam Application Issues

Watery foam during application may indicate reduced concentrate pick-up; increasing proportioning rate from 3% to 6% can be a temporary solution.

System Flushing Procedure

Throttle engine discharge pressure down to idle before flushing.
Flush the hoseline with water until foam is no longer visible.
Engage the eductor backflush button only under 75 psi; do not force above this pressure.
Ensure pressure at the eductor remains below 75 psi while flushing the hoseline.
Shut down the nozzle and expect rapid discharge at a 6% setting during flushing.
Use the red flush button to run fresh water through the pick-up tube until no foam is visible.
Clean any remaining foam residue from the wand metering head and eductor with warm water.

Elevated Foam Stream Evolutions

125 GPM Flow Rate

Conduct a size-up to determine optimal apparatus placement, product type, and proximity to water supply.
If a hydrant is within 300', the aerial can draw directly from it.
Prepare equipment: replace master stream nozzle with a reducer and appropriate fog nozzle rated at 125 gpm @ 75 psi.
Connect the in-line foam eductor to a pump discharge and establish the necessary hose connections.
Charge water line to a minimum EDP of 200 psi and check for suction before immersing the pick-up tube into foam containers.

250 GPM Flow Rate

Follow similar size-up procedures as for 125 GPM flow rate.
Use fog nozzle rated at 250 gpm @ 50 psi.
Set up two foam lines from different apparatus for greater effectiveness.
Ensure aerial discharge and drain valves are closed before charging lines.

350 – 1000 GPM Flow Rate

Requires an ARFF (Aviation Rescue and Firefighting) vehicle, with flow dependent on the resource type.
Similar size-up for positioning and water supply considerations.
Use a 5” hoseline connected to the rear aerial inlet.
All pumping managed by the ARFF vehicle while aerial operations focus on the master stream.

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Description

Test your knowledge on the various types of firefighting foams, their specific applications, and operational procedures. This quiz covers Class A and Class B foams, including their definitions, uses, and considerations for their application in fire emergencies.