1. Compressed Air Foam System
CAFS
Compressed Air Foam System

2. Class Objectives
- Understand the uses for Compressed Air Foam - Understand the basics of the foam concentrate used by the GFD - Understand basic components of the CAFS - Understand the basic operation of the CAFS - Understand the daily and monthly maintenance

3. Uses For Compressed Air Foam
Advantages of Compressed Air Foam
Based on studies starting back in the 1970’s through the 2000’s by numerous agencies which included:
- Texas Department of Forestry
- Boston Fire Department
- Los Angeles City Fire Department
- Los Angeles County Fire Department

4. Uses For Compressed Air Foam
Advantages of Compressed Air Foam
- Uses less water
- extinguishment of given test fire (Boston Fire)
69 gallons = Water
30 gallons = CAF
100 gallons = Water
36 gallons = CAF
- extinguishment of given test fire (LAFD)
75 gallons = Water
16 gallons = CAF
- Less accumulated weight (reduced chance
of structural collapse)

5. Uses For Compressed Air Foam
Advantages of Compressed Air Foam
- Absorbs heat more rapidly due to greater
surface area of a given volume of water
- cool a test fire from 1000 degrees F to 212 degrees F (NIFC)
222.9 seconds = Water
38.5 seconds = CAF
- cool a room from 600 degrees F to 200 degrees F (LAFD)
363 seconds = Water
88 seconds = CAF

6. Uses For Compressed Air Foam
Advantages of Compressed Air Foam
- Reduces the weight of hose lines
- Reduces water and smoke damage
- Reduces property damage
- Deceases rekindle
- Clings to surfaces for exposure protection
- Forms a vapor barrier and excludes oxygen

7. Uses For Compressed Air Foam
Disadvantages of Compressed Air Foam
- Adds expense to apparatus
- Hose reaction can be erratic if air ratio is off
- Accentuates reaction of hose is it ruptures
- Is under utilized do to lack of training

8. Uses For Compressed Air Foam
CAF can be mixed either wet or dry
- Wet CAF
- Fire Attack
- Mansards
- Attic Fires
- Basement Fires
- Overhaul
- Dry CAF
- Pre-treating

9. Foam Concentrate
Phos-Chek WD-881

10. Foam Concentrate Phos-Chek WD-881
- Manufactured by ICL ( was acquired from Monsanto)
- Class A
- Can be used at 0.1 – 1.0% ( recommended % for CAFS)
- 85% reverts to carbon dioxide within 28 days of exposure to ambient conditions in the environment
- Can be used on Class B but will breakdown and must be reapplied (consider accumulation of water due to repeated applications)

11. Foam Concentrate Phos-Chek WD-881
- Health effects and Toxicological Information:
Ingestion: “practically nontoxic”
Skin Contact: “no more than slightly toxic” and moderately irritating
Eye Contact: severely irritating
Inhalation: may cause nose and upper respiratory irritation
- These are greatly reduced when mixed at foam solution concentrations

12. Basic System Components
3 Subsystems Of The Hercules CAFS
- Water Pump
- Foam Proportioning System
- either Husky 10 or 12 depending on year
- Air Compressor
System

13. Basic System Components
Air Compressor System (basic components)

14. Basic System Components
Control Panel
- Turning the compressor on/off
- Setting foam or tool mode
- Displaying the air flow
- capable of at least 140 SCFM at 150psi
- Oil Temperature
- 165 to 210 degrees F normal range
- High oil temperature warning
- Activates at 250 degrees F

15. Basic System Components
Pressure Control Valve
- Operates compressor through a range of 60
to 150psi
- Matches air pressure to water pressure
(+ or - 5%)
Check Valves
- Keeps water from flowing into the air
circuit
- Keeps air from pressurizing back into the
pump

16. Basic System Components
Air Compressor
- Rotary screw type
- Hydraulically driven off transmission PTO
- Oil cooled with thermostat and oil/water heat exchanger that uses discharged pump water to control its temperature

17. Basic System Operation
4 Steps to producing Compressed Air Foam
- Flow Water
- Add Foam
- Add Compressed Air
- Adjust product to desired consistency

18. Basic System Operation
Flow Water
- Check compressor oil (sight gauge) and foam tank levels: part of pre-check
- Engage pump and establish water supply
(tank or hydrant) Intake gated down to 50psi
Note: Manual states 70psi
- Cannot flow additional lines when using
CAF
- Flow water from discharge (Front or Rear)

19. Basic System Operation
Add Foam
- Turn on Husky Foam System
- Adjust percentage to .2 to .5% (default is .5%)
- Confirm foam solution is flowing

20. Basic System Operation
Add Compressed Air
- Turn on Hercules System
(must be under RPM and
less than 30psi air in system)
- Set to “Foam” (“Auto” on some engines)
- Confirm air pressure is building on gauge
- Open CAFS air to Discharge

21. Basic System Operation
Adjusting product to desired consistency (Dry)
- Initial pump discharge at 100 psi
- Gate discharge down to produce dryer foam
- Adjust foam percentage (0.2 – 0.5%)
- Good dry foam can be made as low as .2%
- There tends to be a fine line between good
dry CAF and a hose that pulses with air
pressure

22. Basic System Operation
Adjusting product to desired consistency (Dry)
- Use a nozzle ball valve without the nozzle or
a smooth bore tip (1 3/8”)
- Fog nozzles will strip the air
- Lob foam from a distance or bank off an
object if trying not to disrupt the foam
blanket

23. Basic System Inspection/Maintenance
Check compressor oil
- Daily and after every use
- oil should be between ½ and ¾ on sight gauge
- wait 10 minutes is it was just used
Check hydraulic fluid reservoir
- Visually inspect hoses, filter, compressor for leaks
Operate Husky 10 / 12 monthly
- Prevents foam concentrate from congealing in
lines

24. Basic System Inspection/Maintenance
Operate compressor monthly
- Uncap CAFS Discharge
- Put in pump gear
- Open the discharge air supply valve
- Turn on the compressor
- Bring pump pressure up to 125psi while
recirculating of flowing water
- Run for 10 to 20 minutes
- Monitor pump and compressor temperatures

25. Final Points To Remember
It’s not on the F-295, but exercise the system monthly
- The more it is used, the better it works
- It keeps components and valving moving freely
There is no perfect setting for dry foam
- Each rig is slightly different
- Will require manipulation to dial the system in for good quality foam
- May require periodic adjustment while in use

26. Questions ?