©Copyright Task Force Tips LLC 2010-2021
7
LIU-360 October 14, 2021 Rev05
6.0 USE WITH FOAM
6.1 FOAM SELECTION
Actual foam concentrations vary with changes in water flow, foam concentrate temperature and viscosity. The user must verify that the
concentrate’s performance is suitable for use in their application. Refer to training approved by the AHJ regarding foam concentrate use.
In all cases, the manufacturer’s recommendations must be followed.
6.2 FOAM ATTACHMENT OPTIONS
Expansion ratios vary depending on the type of nozzle used. Refer to training approved by the AHJ when choosing a foam nozzle or
attachment.
Medium Expansion Nozzle
— produces the greatest expansion ratios. It is generally used on Class B fuels for vapor suppression and
Class A fuels when a longer lasting insulating layer of drier foam is desired.
Low Expansion Nozzle
— can be used with either Class A or B foam solutions. Reach is slightly less than the smooth bore. It is
generally used on Class B fires for extinguishment and Class A fuels to soak the fuel with a wet foam solution.
Straight Stream Nozzle
— is for Class A foam solutions. Foam expansion will be negligible. For use where maximum reach or
penetration is desired.
6.3 FOAM CONSUMPTION
The following tables indicate the theoretical foam concentrate flow rate and the time it will take to empty a 5 gallon container of various
concentrates with eductors of different ratings.
The Class B foam used for calibration is the “Universal Gold 1%/3% Alcohol Resistant Aqueous Film Forming Foam (AR-AFFF)” from
National Foam. The calibration viscosity is 2500 centipoise tested with Brookfield #4 Spindle @ 60 rpm The calibration hose length is
50ft.
CAUTION
Mixing of foam concentrates can cause the contents of the foam tank to gel and produce
unpredictable results. To reduce the risk of injury due to unpredictable foam production:
• Do not mix different types of foam concentrates or foams of the same type from different
manufacturers.
• Clean tank and foam passages thoroughly when changing foam types.
250 GPM Eductor
350 GPM Eductor
Setting Foam
Class
Time to Empty
5 Gallons
Foam Flow
Rate in GPM
Setting Foam
Class
Time to Empty
5 Gallons
Foam Flow
Rate in GPM
1/2%
A
4 min
1.25
1/2%
A
2 min 54 sec
1.75
1%
B
2 min
2.5
1%
B
1 min 26 sec
3.5
3%
B
40 sec
7.5
3%
B
29 sec
10.5
6%
B
20 sec
15
6%
B
14 sec
21
800 L/min Eductor
1500 L/min Eductor
Setting Foam
Class
Time to Empty
5 Gallons
Foam Flow
Rate in L/min
Setting Foam
Class
Time to Empty
5 Gallons
Foam Flow
Rate in L/min
1/2%
A
5 min
4
1/2%
A
2 min 40 sec
7.5
1%
B
2 min 30 sec
8
1%
B
1 min 20 sec
15
3%
B
50 sec
24
3%
B
27 sec
45
6%
B
25 sec
48
6%
B
13 sec
90
1000 L/min Eductor
Actual calibrated rate for each setting and
the foam concentration used for calibration
Setting Foam
Class
Time to Empty
5 Gallons
Foam Flow
Rate in L/min
Setting
Actual
Rate
Foam
Class
UL-162
Tolerance
1/2%
A
4 min
5
1/2%
0.58%
A
.5 - .65%
1%
B
2 min
10
1%
1.15%
B
1 - 1.3%
3%
B
40 sec
30
3%
3.45%
B
3 - 3.9%
6%
B
20 sec
60
6%
6.50%
B
6 - 7.8%
