Chapter 16

class A foams are proportioned at ___ % or less

1

class B foams are proportioned from ___ to ___ %

1 to 6

maximum nozzle pressure for a master stream is ___

100 psi

most fog nozzles are designed to operate at a nozzle pressure of ...

100 psi

high expansion foam produces up to ___ parts of finished foam for every one part of foam concentrate

1000

when vaporized, a given volume of water will expand to ___ times its original volume

1700

a gallon of which foam concentrate will product the most foam?

1?

low expansion foam produces up to ___ parts of finished foam for every one part of foam concentrate

20

medium expansion foam produces up to ___ parts of finished form for every one part of foam concentrate

200

what is the range of flow from a 1" solid stream nozzle operated between 50 and 80 psi?

209-264 gpm

under actual fireground conditions, which angle of stream discharged produces the longest reach?

30-34 degrees

master streams are those that flow a minimum of ...

350 gpm

what is the maximum recommended flow from a handline?

350 gpm

a low volume stream discharges a maximum of ...

40 gpm

recommended nozzle pressure for a hand-held solid stream is ___

50 psi

if greater reach and volume are needed from a handheld solid stream, nozzle pressure may be safely increased to a maximum of ___

65 psi

what is the recommended nozzle pressure for most smooth bore master stream appliances?

80 psi

a foam's ability to reduce the surface tension of water will make it effective on class ___ fire

A

which foam is best suited for application with a standard fog nozzle?

AFFF

which is an advantage of a fog stream?

increased heat absorbing capacity

when a fog stream is at maximum reach, what will further increases in nozzle pressure produce?

increased volume

which one of these measures will increase friction loss?

increasing the velocity of the water in the hose

foam extinguishes through all of the following mechanisms EXCEPT ONE. CHOOSE THE EXCEPTION

inhibiting

what method of proportioning forces foam concentrate into the water stream?

injection

which is one of the foam proportioning methods?

injection

how does the low surface tension of class A foam enhance its extinguishing properties?

it causes water to penetrate fuel more easily

what effect does proportioning class A foam in a higher concentration have on the foam?

it creates thicker, dryer foam

which statement about a straight stream is correct?

it is discharged from an adjustable fog nozzle

which statement about an in-line foam eductor is correct?

it uses the venturi principle to draft foam concentrate

which statement about a foam nozzle eductor is correct?

its use may compromises firefighter safety

which is a polar solvent?

laquer thinner

a wide-angle fog pattern has ___ that a narrow-angle pattern

less velocity and reach

what is an advantage of a compressed air foam system (CAFS)?

long reach of hose streams

what is the effect of a surfactant?

lower surface tension

a water aspirating nozzle is designed for use with what kind of foam?

medium expansion foam

the forward velocity of a fire stream is directly generated by ___ pressure

nozzle

the velocity pressure at which water is discharged from a nozzle is ___ pressure

nozzle

which statement about an automatic fog nozzle is correct?

nozzle pressure remains constant despite variations in discharge rate

which on of these statements about foam is correct?

once foam application has begun, it should not be stopped until the fire is extinguished

which appliance mixes the correct amount of foam concentrate with water?

porportioner

portable foam extinguishers are examples of ___ foam systems

premixed

which form of foam proportioning is most commonly used with wheeled extinguishers?

premixing

unlike other nozzles, a manually adjustable fog nozzle permits the nozzle operator to select ___

rate of discharge

which is an advantage of a solid stream?

reach

what is an advantage of a low pressure fog nozzle?

reduced nozzle reaction

in applying class B foam, whether or not the fuel is ignited will affect the ___

required foam application rate

the latent heat of vaporization is the amount of heat ___

required to convert a substance from a liquid to a vapor

which foam application method should only be used for a pool of liquid fuel on the open ground?

roll on

in which method of foam application is a bank of foam formed on the ground in front of the flammable liquid pool and pushed over the flammable liquid by the continued application of foam?

roll-on

which nozzle control valve adjusts the stream pattern as well as controlling the flow?

rotary

foam's ability to ___ creates a barrier between the fuel and the fire

separate

which stream application will cause the lease expansion of the upper layer of fire gases in a compartment?

short pulses of wide-angle fog into the gas layer

past the point of breakover, water from a solid stream becomes ...

showers of spray

foam's ability to ___ prevents the release of flammable vapors

smother

the amount of heat required to raise the temperature of a specified mass of a material by one degree is the definition of ...

specific heat

what is NFPA terminology for a fog nozzle?

spray

what is NFPA terminology for a smooth bore nozzle?

straight tip

the rate of vaporization of water is increased the most by increasing the ___ of the water

surface area

what is a disadvantage of an in-line foam eductor?

the concentrate container must be kept close to the hose

what is the difference, if any, between a straight stream and a solid stream?

the type of nozzle producing the stream

what is a disadvantage of a fog streams?

they are more likely to disrupt thermal layering

which is an appropriate use for class B foam?

to suppress vapor emission from unignited fuels

how can friction loss be reduced?

use large hoseline

which statement about broken streams is correct?

used for basement and attic fires

by which process is a liquid rapidly turned into a gas?

vaporization

what is the function of stacked tips?

vary flow rate

what is the term for a thick, sticky foam?

viscous

which foam is best suited for discharge from a smooth bore nozzle?

CAFS / class A

compared to other stream types, solid streams ___

absorb less heat per gallon discharged

at which stage of foam production are bubbles formed?

aeration

which is the most effective appliance for generating low-expansion foam?

air-aspirating foam nozzle

which nozzle is suitable for use with fluoroprotein foam?

air-aspiring

an installed in-line eductor is a type of ___ proportioner

apparatus-mounted

a balanced pressure proportioner is a type of ___

apparatus-mounted proportioner

what is the most common nozzle control valve?

ball

which foam application method is commonly used for a fire a diked containment area around a storage tank?

bank-down

which foam application method is commonly used for transport vehicle accidents?

bank-down

what is adding foam concentrate to a fire apparatus tank called?

batch mixing

which form of proportioning is the least suitable for use with class B foam concentrates?

batch mixing

which is a hydrocarbon fuel?

benzene

which is a cellar nozzle?

bresnan

which is one of the major classifications of fire streams?

broken

which type of stream is most commonly used for fires in confined spaces?

broken

which nozzle is designed to be lowered through a hole cut in an overhead surface?

cellar

batch mixing is used most commonly for ...

class A foam

what is the primary mechanism by which water extinguishes fire?

cooling

as a nozzle is elevated above the pump, pressure at that nozzle ___

decreases

at a constant flow and pressure, as a fog nozzle pattern widens, the stream reach ___

decreases

what is a distinguishing feature of a constant gallonage fog nozzle?

delivers the same volume regardless of the type of stream pattern selected

steam generation ___ smoke

displaces

which type of class A foam would be most effective for structure protection in the wildland/urban interface?

dry

which method of foam proportioning relies on the venturi principle?

eduction

when water turns to steam, it immediately ___

expands

after aeration, the discharged foam product is called ___ foam

finished

for which application is high expansion form most appropriate?

flooding of confined spaces

water is the solution that is mixed with water and air to produce foam?

foam concentrate

what is the mixture of foam concentrate and water before air is added?

foam solution

what is the term for the effect on pressure as water is forced through hose, appliances, and fittings?

friction loss

the most efficient and effective use of water is achieved by matching the critical flow rate with the ___

heat release rate

a mechanical foam generator is designed for use with what kind of foam?

high-expansion foam