Compressed Air Foam Systems (CAFS) Flashcards
How much class A foam does a CAFS truck hold?
20 to 30 gallons
What lines are typically available for CAFS?
Front jump line
Crosslays
Rear 2 1/2 discharge
Deck gun
What 2 Class A CAFS systems do we have?
Old style- Foam Pro
New style- Husky 10/12
What one air system does our apparatus operate with?
Hercules
What 3 sub systems make up CAFS?
Water pump
Air compressor
Foam concentrate proportioner
How is the air supplied for CAFS?
Supplied by a 200cfm screw-drive compressor.
Where is the air introduces into the foam solution?
Downstream of the discharge valve
What is used to match the compressor pressure (plus or minus 5%) to the discharge water pressure when the compressor rocker switch is activated to the foam side?
The auto pressure balancer valve
When will the CAFS compressors PTO operate?
Only when the fire pump is engaged
What might prevent the compressor PTO to engage?
If the compressor pressure is above 30psi
Look for this on the air pressure gauge
When should he systems be engaged?
At idle
Name the functions for the compressor system control panel
-PTO/ compressor engagement switch (on/off)
-PTO engaged indicator light
-compressor air gauge
-oil temp gauge of CAFS
-audible and visual warning of high temp (250F)
FOAM MODE
-automatic pressure balancer to match compressor discharge pressure to pump discharge pressure between the ranges of 60-150psi
TOOLS MODE
-fixes pressure for the use of air tools
What is the operating temperature of the oil in CAFS?
165-210F
What pressure range does the automatic pressure balancer operate between?
60-150psi
What mode automatically balances pressure to match compressor pressure with pump discharge pressure?
Foam mode
What mode is fixed pressure?
Tools Mode
What circumstance is it recommended to operate the system in tools mode?
It is not recommended in any circumstance to operate in tools mode. Serious injury could result if system is accidentally discharged
What is CAFS airflow monitored in?
SCFM
Standard cubic feet per minute
What must happen before operation of any system?
Daily check
What must be checked before use of CAFS?
The compressor oil reservoir
Should be 1/4 to 1/2 up the sight glass
Where is the sight glass for the CAFS oil reservoir located?
On the right side, lower front, behind the door on the pump panel
How long should you wait to check the CAFS oil reservoir sight glass if the system has been running?
10 min
What percentages can the Foam Pro system deliver?
.1 to 3.0% foam concentrate
What indicates water flow in the Foam Pro system
The red light that indicates the system is on will begin the blink indicating foam injection
What 4 functions does the Foam Pro system display when the grey select button is pressed?
- Flow
- Total water flowed
- % of foam
- Total foam used
What is the default percentage of the Foam Pro system?
.03%
What will be displayed if the water flow rate exceeds the foam pump capacity?
“Hi flow”
What does the operator know if the display on the Foam Pro system flashes “low flow”?
Percentage of foam in the system is rich due to low amount of water in system
What does a “LO/CON” message flashing on the digital display mean?
Foam level is low
What does the CAFS system air compressor use to keep it cool and lubricated?
Oil
What are the operating temperatures for the CAFS compressor?
165 to 210
What oil temp causes and audible alarm and a light to activate?
250 F
What is the most likely cause of an overheating air compressor?
Clogged oil cooler strainer
Water source should not exceed what psi?
125 psi
What should your intake psi and discharge psi be set to?
Gate intake down to 70psi and discharge should be 120 to 125 psi
What difference of pressure is needed for proper cooling?
30 to 40 psi difference
List the 7 steps to start CAFS operation
- Engage pump
- Check the CAFS valves are off and tools/foam switch is in the foam position
- Turn the compressor switch on at idle
- Turn on the foam system
- Open the proper line
- Turn on the CAFS air switch for the proper line
- Throttle up (psi mode) 80 to 125psi
List the 9 steps in shutting down CAFS
- Close air valve switch
- Throttle down PDP
- Turn compressor off
- Turn off foam system
- Flow water until clear from line
- Shut down line
- Throttle to idle
- Push red button on throttle control to clear out system
- Disengage pump per sop
What is the new foam system?
Husky 10/12 foam injection system
What is the maximum gpm of foam concentrate the husky 10 system can support?
10 gpm
What is the maximum gpm of foam concentrate the husky 12 system can support?
12 gpm
Where is the PTO mounted?
The truck transmission
How many gallos is the hydraulic tank?
Approx 4 gallons
What are the 6 buttons on the husky 10/12 control head?
- On/off
- Mode
- Display
- Enter
- Arrow up
- Arrow down
What is the default foam percentage on the husky 10/12 system?
.3%
What are the 5 types of foam?
Type 1/ wet foam Type 2/ medium foam w/ air aspirating nozzle Type 3/ medium foam CAFS TYPE 4/ high expansion foam Type 5/ dry foam
What are the two factors that determine foam type?
Scrubbing and expansion ratio
Define the term scrubbing
The amount of mechanical agitation the air and foam solution receive prior to discharge
Define the term expansion ratio
The amount of air used during the foam generation process.
What is a good indicator that you have flown too much foam I retook?
Foam begins to collect and flow over the floor
What is a benefit to using a CAFS attack?
Less water used
Very efficient flame-extinguishing