Pumping Apparatus Driver/Operator Quiz & Flashcards

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Questions and Answers

What is a foam proportioner?

The raw foam liquid in its storage container before being combined with water and air

The mixture of foam concentrate and water before the introduction of air

The completed product after air is introduced into the foam solution

A device that injects the correct amount of foam concentrate into the water stream (correct)

What is required for mechanical foams to be ready for use?

Pressurization and expansion

Proportioning and aeration (correct)

Separation and filtration

Dilution and heating

What is foam concentrate?

Completed product after air is introduced into the foam solution

Mixture of foam concentrate and water before the introduction of air

Foam solution

Raw foam liquid in its storage container before being combined with water and air (correct)

What is foam solution?

Mixture of foam concentrate and water before the introduction of air Signup and view all the answers

When is foam considered as completed product?

After air is introduced into the foam solution Signup and view all the answers

How do class B foams suppress fires involving hydrocarbon fuels?

They float on the surface of the fuel Signup and view all the answers

What is the specific gravity of hydrocarbon fuels like crude oil and gasoline?

Less than one Signup and view all the answers

What are polar solvent fuels known as?

Miscible liquids Signup and view all the answers

What is the typical water concentration for firefighting foam concentrates?

94 to 99.9 percent water Signup and view all the answers

What method of proportioning foam uses an external pump to force foam concentrate into the fire stream?

Injection method Signup and view all the answers

What is the purpose of the premixing method of proportioning foam?

Mixing premeasured portions of water and foam concentrate in a container Signup and view all the answers

How does foam extinguish and/or suppress vapors?

Separating, cooling, suppressing, or smothering Signup and view all the answers

What is the induction method of proportioning foam?

Using the pressure of a water stream to induct foam concentrate into the fire stream Signup and view all the answers

What method is used when foam is poured directly into the tank?

Batch mixing Signup and view all the answers

What is the range of foam concentrate tank size for fire apparatus equipped with onboard foam proportioning systems?

20 - 200 gallons Signup and view all the answers

How much foam may foam tenders carry for storage?

8,000 gallons or more Signup and view all the answers

How much foam is in a pail?

5 gallons Signup and view all the answers

How much foam is stored in barrels?

55 gallons Signup and view all the answers

How much foam is stored in totes?

275 gallons Signup and view all the answers

What is the shelf life of properly stored foam solution?

20 years Signup and view all the answers

At what percentage may class A foam concentrates be mixed for fire attack and overhaul with standard fog nozzles?

0.2 to 0.5% Signup and view all the answers

What is the application rate in relation to the amount of foam solution applied to a fire?

Per minute, per square foot of fire Signup and view all the answers

What type of foam is suitable for areas requiring maximum penetration?

Wet foam Signup and view all the answers

What is the appropriate percentage range for proportioning class A foam for any application with air aspirating foam nozzles?

0.3 to 0.7% Signup and view all the answers

What is the recommended percentage range for proportioning class A foam for any application with CAFS?

0.2 to 0.5% Signup and view all the answers

What is the recommended shelf life for properly stored synthetic foam concentrate?

20 - 25 years Signup and view all the answers

What is the typical concentration range for Class B foams when used with polar solvents?

3 - 6% Signup and view all the answers

What factors can affect foam expansion?

Type of foam concentrate used, accurate proportioning, and method of aeration Signup and view all the answers

What is the ratio range for medium expansion foam?

20:1 to 200:1 Signup and view all the answers

How is the application rate available from a specific nozzle calculated?

Divide the flow rate by the area of fire Signup and view all the answers

What is the key feature of regular protein foam?

Good heat stability and burnback resistance Signup and view all the answers

What is the defining characteristic of fluoroprotein foam concentrate?

Contains protein concentrate with added fluorochemical surfactants Signup and view all the answers

Which type of foam concentrate is the most commonly used?

AFFF Signup and view all the answers

What is the purpose of fluorochemical surfactants in foam solutions?

To reduce the surface tension of water and spread a thin aqueous film across fuel Signup and view all the answers

What occurs when AFFF or FFFP is applied to hydrocarbon fuel fires?

An air/vapor excluding film is released ahead of the foam blanket Signup and view all the answers

At what concentration is Alcohol Resistant AFFF concentrate generally used?

3 or 6% Signup and view all the answers

What is the basic principle of foam proportioning devices?

A venturi effect created by the pressure of a water stream flowing through a restricted orifice inducts foam concentrate into the water stream. Signup and view all the answers

What is the primary application of high expansion foam?

Concealed space fires Signup and view all the answers

What is the purpose of an in-line foam eductor?

To be attached directly to the pump panel discharge or connected at some point in the hose lay Signup and view all the answers

What is the maximum pressure allowed at the discharge side of the eductor?

70% of eductor inlet pressure Signup and view all the answers

What happens if the inlet pressure at the eductor is too high?

Creates a foam solution that is too rich Signup and view all the answers

The nozzle and eductor must have what to operate successfully?

Same gpm rating Signup and view all the answers

What is the recommended inlet pressure range at the eductor for accurate blending of foam solution?

150 - 200 psi Signup and view all the answers

What height above the foam concentrate should a foam eductor not exceed?

6 ft Signup and view all the answers

What is the purpose of letting the eductor educt water for at least one minute?

To clean thoroughly Signup and view all the answers

What is a disadvantage of an around the pump proportioner?

Inability to flow foam and plain water simultaneously Signup and view all the answers

Which type of foam proportioner is known for its accuracy in foam proportioning and ability to flow plain water and foam simultaneously?

Bypass-type balanced pressure proportioner Signup and view all the answers

What is a limiting factor of using CAFS (Compressed Air Foam System)?

Increases the purchase and maintenance costs Signup and view all the answers

What tactical advantage does CAFS offer in comparison to low energy systems?

Stream reach is longer than low energy systems Signup and view all the answers

What is the typical airflow rate of foam solution used in most structural and wildland operations with CAFS?

0.5 to 1 cubic feet per minute Signup and view all the answers

How are smooth bore nozzles utilized in relation to foam usage?

Limited to class A foam from a CAFS system Signup and view all the answers

What is the primary function of air aspirating foam nozzles?

Induct air into the foam solution by a venturi effect Signup and view all the answers

Which method is used for class B application when a vertical surface is near or within a pool of ignitable liquid?

Bank-down method Signup and view all the answers

How is the biodegradability of foam determined?

By the rate at which natural bacteria can degrade the foam Signup and view all the answers

What did studies by U.S. Forest Service reveal about class A foam in bodies of water?

It can be lethal to fish Signup and view all the answers

What is the standard application ratio when using durable agents as an extinguishing agent?

1:100 Signup and view all the answers

What is the chemical composition of durable agents compared to class A foam?

Water absorbent polymers vs. hydrocarbon based surfactants Signup and view all the answers

For structure protection, what is the recommended application ratio for durable agents?

2 to 3% Signup and view all the answers

Study Notes

Foam Proportioning Overview

A foam proportioner is a device used to mix foam concentrate with water to create foam solution for firefighting.
Mechanical foams need water, foam concentrate, and air to be ready for use.

Foam Concentrates and Solutions

Foam concentrate is a concentrated liquid that, when mixed with water, generates foam.
Foam solution is the mixture of foam concentrate and water before it is dispensed.

Foam Completion and Fuel Types

Foam is considered a completed product once the foam solution is properly mixed and ready for discharge.
Class B foams effectively suppress fires involving hydrocarbon fuels by forming a barrier that prevents oxygen from reaching the fuel.

Specific Gravity and Fuel Classification

Hydrocarbon fuels like crude oil and gasoline typically have a specific gravity of around 0.6 to 0.8.
Polar solvent fuels are known as water-miscible fuels.

Concentration and Storage

Typical water concentration for firefighting foam concentrates ranges from 3% to 6%.
An external pump method of proportioning foam uses a pump to force foam concentrate into the fire stream.

Proportioning Methods

Premixing method of proportioning foam mixes foam concentrate with water prior to application.
Induction method involves drawing foam concentrate into the water stream using a venturi effect.
Pouring foam directly into the tank is known as the pour-in method.

Foam Storage Capacities

Foam concentrate tank sizes on fire apparatus can range from 20 to 500 gallons.
Foam tenders can carry up to 1,000 gallons or more for storage.
A pail typically contains 5 gallons of foam concentrate.
Barrels usually hold 55 gallons of foam.
Totes can store 275 gallons or more of foam.

Foam Solution Shelf Life and Application

Properly stored foam solution has a shelf life of 10 years or more.
Class A foam concentrates can typically be mixed at 0.1% to 1% for fire attack and overhaul with standard fog nozzles.

Application Rate and Types of Foam

Application rate refers to the amount of foam solution applied per unit area of the fire.
High expansion foam is suitable for maximum penetration in confined spaces.
The appropriate percentage range for proportioning Class A foam with air aspirating nozzles is 0.1% to 1%.

Specific Foam Recommendations

Recommended percentage range for Class A foam when using CAFS (Compressed Air Foam Systems) is typically 0.3% to 1%.
Properly stored synthetic foam concentrate usually has a shelf life of around 10 years.

Class B Foam Concentrations

Typical concentration range for Class B foams when used with polar solvents is 3% to 6%.

Foam Expansion Factors

Factors affecting foam expansion include the type of proportioner, water quality, and concentrate formulation.
Medium expansion foam typically has a ratio range of 10:1 to 100:1.

Application Calculations and Foam Types

Application rate calculations from nozzles depend on flow rate and nozzle size.
Regular protein foam features a protein base, while fluoroprotein foam concentrate contains additional fluorochemical additives.

Foam Behavior and Application Techniques

AFFF (Aqueous Film Forming Foam) or FFFP (Film Forming Fluoroprotein) applied to hydrocarbon fires displaces oxygen and cools the fuel.
Alcohol Resistant AFFF concentrate is generally used at a concentration of 3% to 6%.

Foam Proportioning Devices

Foam proportioning devices work on the principle of mixing foam concentrate with water to achieve desired ratios.
High expansion foam is primarily used in confined space situations to displace air.
An in-line foam eductor allows for continuous mixing and application of foam solution.

Eductor Specifications

Maximum pressure allowed at the discharge side of the eductor is typically around 100 psi.
If inlet pressure is too high at the eductor, it may reduce foam effectiveness or damage the unit.

Eductor Requirements

Successful operation of the nozzle and eductor requires proper matching of flow rates and pressures.
Recommended inlet pressure range for accurate blending of foam solution is 50 to 70 psi.
Height above the foam concentrate for the eductor should not exceed 10 feet to maintain suction.

Eductor Operation

Letting the eductor educt water for one minute allows for proper priming and mixing of foam solution.

Proportioner Disadvantages and Advantages

Around the pump proportioners may lead to inaccurate mixing ratios, especially at low flow rates.
Accurate foam proportioners can flow plain water and foam simultaneously for effective dispensing.

CAFS Considerations

A significant limiting factor of using CAFS is the need for a high airflow rate, which may require a larger apparatus.
CAFS offers tactical advantages such as faster application rates and better coverage compared to low energy systems.

Structural and Wildfire Applications

Typical airflow rates of foam solution with CAFS in structural and wildland operations can vary but are often around 20 to 40 CFM.
Smooth bore nozzles are utilized to deliver a solid stream of foam solution effectively.

Nozzle Functions and Application Methods

The primary function of air aspirating foam nozzles is to create an expanded foam through aeration.
For class B foam applications, particularly near ignitable liquid pools, specific techniques must be used to mitigate the flames.

Foam Biodegradability and Environmental Considerations

Biodegradability of foam is usually determined through laboratory testing and environmental impact assessments.
Studies by the U.S. Forest Service indicated that Class A foam has minimal long-term environmental effects in bodies of water.

Durable Agents and Ratios

The standard application ratio for durable agents as extinguishing agents typically ranges from 0.3:1 to 0.5:1.
Durable agents have a chemical composition that differs from Class A foam, offering unique benefits for structure protection.
For structure protection, the recommended application ratio for durable agents ranges from 0.5:1 to 1:1.

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Pumping Apparatus Driver/Operator Chapter 14

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