Class B Foam

Question 1

What pumpers and ladders are equipped with built in foam eductor systems and a 20 gallon Class B foam tank?

Answer 1

1988-2000

Question 2

They achieve a rated flow with an inlet pressure of 200psi with how many gpm nozzle?

Answer 2

95 gpm nozzle

Question 3

The metering valve has five notched settings which are?

Answer 3

0, 1/2, 1, 3 and 6% marks

Question 4

How do you change the metering %?

Answer 4

Push knob in and align with the desired % then release the knob

May have to pull the knob out if it does not pop out

Question 5

Foam should start flowing from what psi?

Answer 5

125-200psi PDP

Question 6

What are the steps to flush the foam system properly?

Answer 6

1. Reduce pump psi to 100 or less
2. Close the foam valve
3. Open flush valve and small 1/4 in foam drain/metering flush valve
4. Flush for 5 to 10 min or until the water is clear
5. Close 1/4 in foam drain/metering flush valve
6. Close eductor valve and flush valve
7. Close foam water discharge valve

Question 7

What class B foam do pumpers and ladders use?

Answer 7

3% / 6% Ansulite AFFF B foam

Question 8

What foam does crash units use?

Answer 8

3% class b foam

Question 9

Can you mix foams together?

Answer 9

NO!

Question 10

What might happen if class a and class b foam are mixed together in a system?

Answer 10

The foam will gel and plug all components making the foam system inoperable

Question 11

What are some reasons an eductor may fail?

Answer 11

• metering knob not pulled out
• foam handle not pulled out all the way
• nozzle not 95gpm
• foam tank empty
• ball valve stuck (call maintenance)
• partially closed nozzle (need 95gpm)
• hose lay too long
• clogged nozzle
• foam tank not vented
• kink in hose
• metering valve clogged with dry foam
• too much nozzle elevation

Question 12

Uses for class b foam

Answer 12

• Vapor suppression for liquid spills to prevent ignition or to extinguish fire
• extinguish vehicles and rail cars
• refineries and chemical plants
• facilities with flammable liquids
• production of textiles, drugs and other products

Question 13

What is low expansion foam best suited for?

Answer 13

Fire attacks on class b fires. It provides penetration power and rapid extinguishment

Question 14

What is a fog nozzle with a foam aeration attachment best suited for?

Answer 14

Applying a foam blanket