Chapter 14 - Foam Equipment and Systems Flashcards
When large-scale flammable and combustible liquid fires require the delivery of an amount of foam that is beyond the capability of the handlines, which of the following should be used?
Master stream foam nozzles
page 504
Other additives currently available for use as extinguishing agents, as well as pre-treatment of structures threatened by fire spread, are generally known as:
durable or gelling agents.
page 508
Which of the following is a common type of portable foam proportioner?
In-line foam eductor
page 494
When using low energy portable foam application systems, the aeration and discharge functions are completed by:
an aerating foam nozzle.
variable-flow demand-type balanced pressure proportioners consists of a variable speed mechanism driven electrically or hydraulically that operates a:
foam concentrate pump.
Batch mixing is generally only used with which types of foam concentrates?
Class A and regular AFFF concentrates
Which foam consists of fluorochemical and hydrocarbon surfactants combined with solvents to create a high boiling point?
Aqueous film forming foam (AFFF)
Both of the basic types of medium- and high-expansion foam generators produce foam containing __________ content.
high air content.
Which foam is MOST likely to be used to combat concealed space fires in cellars or other subterranean spaces?
High-expansion foam
Batch mixing is generally only used with which types of foam concentrates?
Class A and regular AFFF concentrates
Which is the most common apparatus-mounted foam proportioner and consists of a small return (bypass) water line connected from the discharge side of the pump back to the intake side of the pump?
Around-the-pump proportioner
What is the smallest type of foam storage container?
Select one:
Pails
A type of in-line eductor that may be used to supply foam concentrate to a self-educting master stream foam nozzle is called a:
jet ratio controller
Because it forms a rigid coating that adheres well and is slow to drain, the best consistency of Class A foam for vertical surfaces is:
dry foam
Installed in-line eductors are most commonly used to proportion which class of foam?
Class B
Low energy foam systems impart pressure on the foam solution with the use of the:
main fire pump
What are Mil-Spec concentrates?
Foam concentrates manufactured to U.S. Military specifications
The minimum amount of foam solution that must be used on a fire per minute per square foot (square meter) of fire is called the:
application rate.
What is the commonly used guideline for proportioning Class A foam for exposure protection with standard fog nozzles?
0.5 to 1.0 percent concentrate
Which piece of equipment injects the correct amount of foam concentrate into the water stream to make the foam solution?
Foam proportioner
Class B synthetic foam concentrate is made from:
a mixture of fluorosurfactants.
when an in-line proportioner is used, a partially closed nozzle will result in a flow rate that will:
not allow the creation of a Venturi effect
Which kind of nozzle allows firefighters the option of operating fixed flow, selective flow, or automatic flow when applying a low expansion, short duration foam blanket?
Fog nozzles
Why might fuel and fire consume a portion or the entire foam blanket?
Inconsistent application time
regular protein foams _______ more quickly and are becoming increasingly rare.
degrade
Class A foam solutions do not retain their foaming properties when mixed in water for more than:
24 hours
When using the batch mixing proportioning method, frothing can be avoided by:
slowly circulating water in the tank.
Which factor is most likely to affect the degree of expansion in a foam solution?
Method of aeration
In some installed in-line eductor systems, a(an) _____ proportioner is installed to reduce the friction loss across the eductor.
bypass
a disadvantage of durable agents is once applied, surfaces coated with these products become:
very slippery for walking or driving.
Which of the following has a pickup tube that is located in the center bore of the nozzle and uses a modified Venturi design to draw concentrate into its water stream?
Self-educting master stream foam nozzle
designed to work in conjunction with proportioners to produce the best possible foam?
Foam nozzles
A smooth bore nozzle is limited to application of which classification of foam?
Class A foam from a CAFS
Driver/operators calculate the application rate available from a specific nozzle by:
dividing the flow rate by the area of the fire.
Which variable affects a foam’s rate of application?
Whether the fuel is contained or uncontained
Ambient ___________ affects the breakdown process of Class A foam.
air temperature
Regardless of the type of tank, what is one characteristic that all foam storage containers share?
Airtight storage
Which proportioning method uses an external pump to force foam concentrate into the fire stream at the proper ratio in comparison to the flow?
Injection
In which situation is it acceptable to mix together different manufacturers’ foam concentrates?
If they are mil-spec concentrates
In what way are durable agents similar to Class A foam?
Both products are used in a similar fashion.
The act of mixing water with foam concentrate to form a foam solution is called:
proportioning.
Which kind of nozzle inducts air into foam solution by a Venturi action and is the only nozzle that should be used with protein and fluoroprotein concentrates?
Air-aspirating foam nozzles
The process of foam decomposition results in the consumption of:
oxygen.
Due to the low eduction rates on a CAFS apparatus, what is required to supply the fire stream at the rate of 0.1 to 1.0 percent?
A variable flow rate sensing proportioner
Which is a proportioner used on large mobile apparatus installations, such as ARFF vehicles, and is one of the most accurate methods of foam proportioning?
Bypass-type balanced pressure proportioner
A limitation of CAFS is In the event of a hose burst, compressed air will:
intensify the reaction of the hoseline
Which proportioning method uses premeasured portions of water and foam concentrate that are mixed in a container?
Premixing
