Foam Extra Study

Question 1

What gives Alcohol Resistant Fluoroprotein Foam its alcohol resistance?

Answer 1

Addition of ammonia salts suspended in organic solvents, lasting approximately 15 minutes.

Question 2

What are the three actions of AFFF?

Answer 2

1. Releases an air/vapor-excluding film ahead of the foam blanket. 2. Fast-moving foam blanket spreads across surfaces, surrounding objects and insulating. 3. Drains water, releasing more film to recover or ‘heal’ disturbed areas.

Question 3

What is the most commonly used synthetic foam concentrate?

Answer 3

Aqueous Film Forming Foam (AFFF).

Question 4

Can most foams be mixed? What is the exception?

Answer 4

Most foams should not be mixed. Exception: AFFF and fluoroprotein foams of similar concentrations can be mixed immediately before application.

Question 5

Why does high expansion foam cause less damage to a site?

Answer 5

It creates less water runoff compared to other foams.

Question 6

On what type of fires is high expansion foam effective?

Answer 6

Class A fires.

Question 7

What are the two basic systems for proportioning foam concentrates?

Answer 7

1. Low Energy (e.g., in-line foam eductors, foam nozzle eductors, self-educting master stream nozzles). 2. High Energy (e.g., CAFS - Compressed Air Foam System).

Question 8

How do Low-Energy foam systems work?

Answer 8

Inject foam concentrate into the water stream at a set ratio and higher pressure than the water flow.

Question 9

What is a Self-Educting Master Stream Foam Nozzle?

Answer 9

A large-capacity nozzle with a built-in foam eductor, capable of flows greater than 350 GPM.

Question 10

What logistical issue is associated with Foam Nozzle Eductors?

Answer 10

The foam concentrate must stay with the nozzle.

Question 11

How does a Self-Educting Master Stream Foam Nozzle draw concentrate?

Answer 11

It has a unique design with a pickup tube in the center of the nozzle.

Question 12

What is the maximum flow capacity of some Self-Educting Master Stream Foam Nozzles?

Answer 12

Up to 14,000 GPM.

Question 13

What is a Jet-Ratio Controller?

Answer 13

A type of in-line eductor used to supply a Self-Educting Master Stream Foam Nozzle, allowing foam concentrate supply up to 3,000 ft away and 50 ft in elevation change.

Question 14

Are ‘installed’ In-Line foam eductors suitable for Class A foam?

Answer 14

No, due to the low concentrations required for Class A foam.

Question 15

What is the most common proportioning system on modern fire apparatus?

Answer 15

Around the Pump proportioners.

Question 16

Why are Variable-Flow Variable-Rate Direct Injection Systems not usable with Alcohol Resistant Foams?

Answer 16

Due to the viscous nature of Alcohol Resistant Foams.

Question 17

When is Batch Mixing typically used?

Answer 17

Generally used with Class A foam and regular AFFF (not alcohol resistant).

Question 18

How does CAFS create finished foam?

Answer 18

Injects air into the foam solution, creating finished foam in the hose line.

Question 19

What is the source of air for CAFS?

Answer 19

A rotary compressor.

Question 20

What is the Rain Down method?

Answer 20

Foam is directed into the air and swept back and forth until the target area is well blanketed.

Question 21

What determines the biodegradability of foam?

Answer 21

The rate at which environmental bacteria degrade the foam.

Question 22

What happens during the decomposition of Class A and Class B foams?

Answer 22

It results in the consumption of oxygen.

Question 23

What have studies shown about the impact of Class A foams on fish?

Answer 23

Class A foams are lethal to fish, according to the National Forestry Service and National Biological Survey Office.

Question 24

How do Durable Agents compare to Class A Foam in terms of water retention?

Answer 24

Durable Agents absorb water and retain their retarding properties longer than Class A Foam.

Question 25

How long can Durable Agents adhere to vertical surfaces?

Answer 25

Up to 24 hours.

Question 26

What are the Durable Agent ratios for different applications?

Answer 26

Extinguishing Agent: 1:100 Fire Line: 1.5% to 2% Structural Protection: 2% to 3%

Question 27

What are some names for Durable Agents?

Answer 27

Gelling Agents, Fire Blocking Gels, Aqueous Fire Fighting Gels.

Question 28

What are Durable Agents chemically?

Answer 28

Water-absorbent polymers.

Question 29

What safety concern arises when Durable Agents are applied?

Answer 29

They make surfaces very slippery for walking and driving.

Question 30

What is Mechanical Foam?

Answer 30

Foam produced by physical agitation of foam concentrate, water, and air.

Question 31

What is Proportioning in foam production?

Answer 31

Mixing water with an appropriate amount of foam concentrate to form a foam solution.

Question 32

What is Aeration in foam production?

Answer 32

The introduction of air into a foam to create bubbles, resulting in finished foam.

Question 33

What is Foam Concentrate?

Answer 33

Raw foam liquid that has not been mixed with water and air.

Question 34

What is Foam Solution?

Answer 34

The result of mixing foam concentrate and water, before the introduction of air.

Question 35

What is a Hydrocarbon?

Answer 35

A petroleum-based organic compound containing only hydrogen and carbon.

Question 36

What is a Polar Solvent?

Answer 36

A liquid with a molecule where positive and negative charges are permanently separated, allowing it to ionize in solution.

Question 37

What does Miscible mean?

Answer 37

Describes materials capable of being mixed in all proportions.

Question 38

What is the proportion range for Class A Foam?

Answer 38

0.1% to 1.0%.

Question 39

What is the Injection Method for proportioning?

Answer 39

Uses an external pump or head pressure to force foam concentrate into a fire stream at the correct ratio for the desired flow.

Question 40

What is Batch Mixing in foam production?

Answer 40

Adding an appropriate amount of foam concentrate to a water tank before application to produce foam solution.

Question 41

What is Premixing in foam production?

Answer 41

Mixing pre-measured portions of water and foam concentrate in a container.

Question 42

What are Totes in foam storage?

Answer 42

275-gallon containers used for bulk foam storage by some fire departments and industrial facilities.

Question 43

What is the shelf life of different foam types?

Answer 43

Protein Foam: 10 years Class B Synthetic Foam: 20-25 years Class A Foam: 20 years

Question 44

What are Military Specifications in foam?

Answer 44

Specifications developed by the U.S. Department of Defense for foam.

Question 45

What is Foam Expansion?

Answer 45

The result of adding air to a foam solution, creating foam bubbles that result in finished foam.

Question 46

What does Hydrolyze mean in foam context?

Answer 46

To cause or undergo a chemical decomposition process involving the splitting of a bond and the addition of water.

Question 47

What is Burnback Resistance?

Answer 47

The ability of a foam blanket to resist direct flame impingement.

Question 48

What is Aqueous Film Forming Foam (AFFF)?

Answer 48

Foam that creates a complete vapor barrier over fuel spills and fires, effective for extinguishing and blanketing hydrocarbon fuels.

Question 49

What is Film Forming Fluoroprotein Foam (FFFP)?

Answer 49

Foam that combines qualities of Fluoroprotein and AFFF foam.

Question 50

What is Protein Foam made of?

Answer 50

Contains protein hydrolysate and additives.

Question 51

What is an In-Line Foam Eductor?

Answer 51

A foam delivery device located in the water supply line near the nozzle.

Question 52

What is the pressure rule for In-Line Foam Eductors?

Answer 52

The pressure on the discharge side of the eductor must not exceed 70% of the eductor inlet pressure.

Question 53

What is Back Pressure in foam systems?

Answer 53

Pressure loss or gain caused by changes in elevation between the nozzle and pump.

Question 54

How does an Around The Pump Proportioner work?

Answer 54

Diverts a small amount of water (10-40 GPM) from the pump through the inlet side to flow through foam proportioner piping.

Question 55

What limitation do older Around The Pump Proportioners have?

Answer 55

Must use tank water because pressures above 10 psi prevent foam from entering the intake side.

Question 56

What is a Bypass-Type Balanced Pressure Proportioner?

Answer 56

Operates with a fire pump to ensure a proper foam concentrate-to-water mixture; one of the most accurate proportioning methods, used in ARFF vehicles.

Question 57

What is a Variable-Flow Variable-Rate Direct-Injection System?

Answer 57

Injects the correct amount of foam into pump piping, supplying all discharges with foam while maintaining consistent foam solution quality. Not usable with AR-AFFF due to viscosity.

Question 58

What is a Variable-Flow Demand Type Balanced-Pressure Proportioner?

Answer 58

Used in fixed and mobile applications; a variable-speed mechanism drives the foam pump and monitors flow to produce effective foam solution.

Question 59

What is the airflow rate for CAFS to produce dry foam?

Answer 59

Generally flows 2 cubic feet per minute (cfpm) of airflow per gallon per minute of foam solution, up to 100 GPM.

Question 60

What is the Roll On Method also known as?

Answer 60

The 'Bounce' method of foam application.

Question 61

What is an Air Drop in firefighting?

Answer 61

The process of dropping water, short-term fire retardant, or long-term fire retardant from an air tanker or helicopter onto a wildland fire.

Question 62

Why have more fire services invested in foam systems?

Answer 62

Newer foam concentrates are more easily used by structural and wildland firefighters.

Question 63

Who is responsible for assembling and operating foam firefighting equipment at the company level?

Answer 63

The Driver/Operator.

Question 64

What is Fluoroprotein Foam?

Answer 64

A combination of protein and synthetic foam.

Question 65

What are the majority of foams used today?

Answer 65

Mechanical Foams.

Question 66

Can Class B foams designed for hydrocarbon fires extinguish polar solvent fires?

Answer 66

No.

Question 67

Why are polar solvent fuels like alcohol, acetone, ketones, and esters considered miscible?

Answer 67

They mix with water in all proportions.

Question 68

How must foam be stored?

Answer 68

In airtight containers.

Question 69

Which foam type has the least environmental impact?

Answer 69

Protein foams.

Question 70

What are the expansion rate ranges for foam?

Answer 70

Low: 0-20 Medium: 20-200 High: 200-1000

Question 71

What is the formula for Application Rate?

Answer 71

Flow Rate in GPM ÷ Area of Fire (GPM/Area of Fire).

Question 72

Are Protein Foams resistant to burnback?

Answer 72

Yes.