Compressed Air Foam System

- 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

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

Advantages of Compressed Air Foam

- Uses less water - extinguishment of given test fire (Boston Fire) 69 gallons = Water 30 gallons = CAF

- extinguishment of given test fire (Boston Fire) 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)

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

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

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

CAF can be mixed either wet or dry

- Wet CAF - Fire Attack - Mansards - Attic Fires - Basement Fires - Overhaul

- Dry CAF - Pre-treating - Overhaul

Phos-Chek WD-881

Phos-Chek WD-881 - Manufactured by ICL ( was acquired from Monsanto)

- Class A

- Can be used at 0.1 – 1.0% ( recommended 0.2 -0.5% 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)

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

3 Subsystems Of The Hercules CAFS

- Water Pump

- Foam Proportioning System

- either Husky 10 or 12 depending on year

- Air Compressor System

Air Compressor System (basic 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

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

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

4 Steps to producing Compressed Air Foam - Flow Water

- Add Foam

- Add Compressed Air

- Adjust product to desired consistency

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)

Add Foam

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

Add Compressed Air

- Turn on Hercules System (must be under 1000 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

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

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

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

- Daily and after every use

- Visually inspect hoses, filter, compressor for leaks

Operate Husky 10 / 12 monthly - Prevents foam concentrate from congealing in lines

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

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