Chapter 10 Types of Fire Streams

Question 1

What are the four basic elements needed to produce a fire stream

Answer 1

1. water source
2. means to impart pressure
3. means to transport water
4. personnel trained in the first three elements

Question 2

the four principal types of firehose appliances are:

Answer 2

wyes
siamese
water theifs
manifolds

Question 3

small wyes used to break one medium diameter supply hose into two 1 3/4” or smaller attackers are known as ___?

Answer 3

leader line wyes

Question 4

solid streams are classified as good if they have the following physical characteristics at point of breakover

Answer 4

1. stream has not lost continuity by breaking up
2. stream appears to shoot 90% of whole volume inside a circle 15” in diameter and 75% of it inside a 10” circle, by eye
3. stream is stiff enough to attain the required height through moderate breeze

Question 5

Given equal discharge pressures, when the diameter of the discharge opening of a solid stream smoothbore nozzle is doubled the flow capacity _____

Answer 5

quadruples

Question 6

Most fire departments and training authorities advocate that the nozzle pressure on a handline solid stream nozzle not exceed____ … for master streams solid stream nozzles___

Answer 6

50 psi

80 psi

Question 7

given equal discharge pressures the reach of the stream will increase as the diameter of the discharge orifice is____

Answer 7

increased

Question 8

the solid streams maximum horizontal reach is at an angle of___ to the earth’s surface

Answer 8

32 degrees

Question 9

what angle gives a solid stream the greatest vertical reach into structures

Answer 9

70-75 degrees

Question 10

Handlines, typically if the nozzle tip’s diameter exceeds ___ of the diameter of the hose stream quality will be lowered

Answer 10

60%

Question 11

what are the five advantages and four disadvantages of solid streams

Answer 11

advantages: 1. better visibility, 2. greater reach, 3. lower nozzle pressure 4. greater penetrating power, 5. less likely to disturb thermal layering
disadvantages: 1. one stream pattern 2. can’t use class B foam 3. less heat absorption, 4. conduct electricity

Question 12

who are the four people who helped develop fog streams

Answer 12

Griswold, Layman, Royer , Nelson

Question 13

what is the difference between velocity and speed

Answer 13

velocity is a rate of motion in a particular direction

speed is rated travel regardless of direction

Question 14

fog stream selection must consider five factors

Answer 14

1. gravity
2. water velocity
3. fire stream pattern
4. water droplet friction with air
5. wind

Question 15

the two main reasons of fog stream will never be used from outside the structure

Answer 15

1. reduced reached

2. inability to hit seat of the fire ( converted to steam)

Question 16

type of fire fog streams are useful for fighting

Answer 16

enclosed fires

Question 17

if the fog stream has a broken or otherwise unsatisfactory pattern likely culprit is

Answer 17

insufficient nozzle pressure

Question 18

most standard fog nozzles are designed for optimal flow in streams operation at a discharge pressure of____

Answer 18

100psi

high-rise files fog nozzles may be as low 50 PSI

Question 19

was a key factor in a fog streams of effectiveness in controlling fire

Answer 19

confined space with maximum conversion to steam

Question 20

what are the disadvantages and advantages of fog streams

3/7

Answer 20

advantages: 1. dissipate heat by exposing maximum water surface for heat absorption 2. adjustable patterns 3. vary from straight stream to wide fog pattern 4. adjustable water usage 5. aid ventilation 6. nondestructive stream7. will not conduct electricity 7. class A and class B foam
disadvantages: 1. less reach and penetrating power than solid streams 2. more susceptible to wind 3. may contribute to fire spread

Question 21

what is a broken stream?

Answer 21

stream will water that has been divided into core straps having characteristics of both a solid and fog stream. series of small solid streams that quickly break up

Question 22

what are some differences between fog streams and broken streams

Answer 22

fog streams have a definite pattern broken streams do not

broken streams have larger drops of water and are generally not adjustable

broken streams conducted electricity

Question 23

what are the disadvantages and advantages of broken strengths

Answer 23

advantages: 1. often the only means to applying water to fires and otherwise inaccessible spaces 2. have more heat absorbing capacity than solid streams
disadvantages: 1. may conduct electricity, no class C fires 2. method of water application may not be optimal, can produce more water damage than other streams 3. each broken stream nozzle typically has one application