Foam

Question 1

Fire Tetrahedron

Answer 1

Fuel, Oxygen, Heat, Chemical Chain Reaction

Question 2

Proportion rates for Class A foam

Answer 2

0.2% for overhaul, 0.5% for fire attack, 1.0% exposure protection

Question 3

What type of nozzle should be used with CAFs and why?

Answer 3

Use a solid bore nozzle for greater reach and penetration. Fog nozzle will strip some of the air from the foam and have a reduced reach

Question 4

What is slug flow?

Answer 4

Not enough foam concentrate injected into the stream. Presents as a rapidly pulsating hose line caused by alternating slugs of air and water without enough foam concentrate.

Question 5

What is a hydrocarbon fire?

Answer 5

Gasoline or diesel

Question 6

What is a polar solvent fire?

Answer 6

Alcohol-based

Question 7

What type of Class B foam is predominantly used in the fire service?

Answer 7

AFFF - Aqueous Film-Forming Foam. It forms a film on the surface of the liquid fuel and excludes the oxygen.

Question 8

NFPA recommendation for foam and water supply

Answer 8

15-minute supply before any fire attack

Question 9

Proportion rates for Class B foam

Answer 9

3% for hydrocarbons, 6% for polar solvents

Question 10

Novacool can be used on which types of fires?

Answer 10

Class A, B, D, and K fires

Question 11

How does Novacool work?

Answer 11

It is an emulsifier, it mixes with the product and renders it inert or unable to burn.

Question 12

Proportion rates for Novacool

Answer 12

0.1% for overhaul/wildland, 0.4% for fire attack

Question 13

3/2/1 rule of portable foam eductor

Answer 13

Nozzle must be within 300 feet of the eductor. PDP must be 200 psi at the eductor. 95 GPM nozzle

Question 14

Proportion rates for Novacool and portable foam eductor

Answer 14

0.5%

Question 15

Type of air compressor in a CAF system

Answer 15

Rotary air compressor

Question 16

Advantages of CAF foam

Answer 16

Better reach, Durable air bubbles, Resists heat longer, Reach from a greater distance, Lines are lighter and more durable

Question 17

Disadvantages of CAF foam

Answer 17

Price and maintenance costs, erratic hose lines if inadequate foam or burst section, additional training

Question 18

Critical Application Rate of CAF

Answer 18

30-40% of plain water

Question 19

Two types of flow meters/foam pump/proportioner

Answer 19

FoamPro or Husky

Question 20

Air compressor capacity in a CAF system

Answer 20

200 SCFM (Standard Cubic Feet per Minute) at 160 psi

Question 21

What should the air pressure be when in Foam mode on a CAF system?

Answer 21

120 psi

Question 22

Manufacturer recommended differential between incoming and outgoing pressure on CAF system?

Answer 22

50 psi

Question 23

Why the pressure differential requirement for a CAF system?

Answer 23

A “zero net” difference does not allow the cooling water to circulate, eventually leading to the compressor overheating.

Question 24

How to create dry foam in a CAF system

Answer 24

Gate down the discharge valve slightly, reducing the water and increasing the air.

Question 25

FoamPro pump capacity

Answer 25

2.6 gpm

Question 26

Husky 10 system capacity

Answer 26

12 gpm

Question 27

Critical Application Rate for hydrocarbons

Answer 27

0.1 GPM/ft2

Question 28

Critical Application Rate for polar solvents

Answer 28

0.2 GPM/ft2

Question 29

Max height from eductor to bucket

Answer 29

6 feet