NOTE: It is important that you do not lose all the water in the pump. If you do, you must prime the
pump again before you can proceed. Also, make sure caps are on both discharge pipes on the
Step 3. Fill the prime-detergent tank with approximately 5 gallons of foam-forming liquid concentrate,
Step 4. Open valve 1 and, as appropriate, valves 2, 3, or both. Open valve 2, if the lower hose reel is to
be used, valve 3, if the upper reel is to be used, and both if both reels are to be used.
Step 5. Turn valve 4 to the half-open position and open the tank drain valve by turning the valve handle
five full turns.
You are now ready to spray a mixture of foam metered with water. Hold the gun assembly as described
for holding it when spraying water with detergent. Grasp the extension pipe where it joins the foam
Hold the gun assembly tightly. The foam mixture is discharged under
high pressure, which night cause you to lose control of the hose.
To spray the foam mixture, proceed as follows:
Step 1. Turn the ball valve handle counterclockwise to discharge the foam mixture.
Step 2. Watch the foam for the correct consistency as it is discharged. It should be thick and fluffy. If
it is thin and watery, close the ball valve on the gun assembly and adjust the mixture. Turn the tank
drain valve in one-quarter turn increments toward the closed position until mixture reaches the proper
consistency. Discharge more foam. If the foam is now thick and fluffy, you are ready to fight the fire.
If it is still thin and watery, adjust the mixture until the foam is thick and fluffy.
NOTE: It is important that you NOT meter the foam too fast. If you meter the foam too fast, you will
use all the concentrate in the prime tank and the pump will lose pressure before all the water in
the tank unit is used.
As with spraying water and detergent, when the M12A1 PDDA is used to fight fires by spraying foam,
one person must watch and operate the control panel while the fire fighters use the hoses.