Chapter 7 Fire Hose Nozzles and Flow Rates

Question 1

During the time a stream of water or extinguishing agent passes through space, it is influenced by what?

Answer 1

Velocity, gravity, wind, and friction

pg. 165

Question 2

What are the three basic types of fire streams used by the fire service?

Answer 2

1. solid
2. fog
3. broken

pg. 165

Question 3

What is a solid stream?

Answer 3

a fire stream produced from a fixed orifice, smoothbore nozzle.

pg. 165

Question 4

What equipment/ hose types are solid stream used on?

Answer 4

handlines,
portable or apparatus mounted master streams,
elevated master streams

pg. 165

Question 5

What determines the flow and stream reach from a solid stream nozzle?

Answer 5

nozzle pressure and the size of the discharge opening

pg. 166

Question 6

When used on handlines, what psi should solid streams be operated at?

Answer 6

50 psi

pg. 166

Question 7

A solid stream master stream device should be operated at what psi?

Answer 7

80 psi

pg. 166

Question 8

What is the formula to determine the amount of water in GPM being discharged from a solid stream device?

Answer 8

GPM=29.7 x d² x √NP

d=diameter of orifice in mm
NP= nozzle pressure in kPa

Question 9

What is periphery?

Answer 9

the line bounding a rounded surface; the outward boundary of an object distinguished from its internal regions

Question 10

What is deflection?

Answer 10

A turning or state of being turned; a turning from a straight line or given course; a bending; a deviation.

Question 11

What is meant to impinge?

Answer 11

To strike or dash about or against; clashing with a sharp collision; to come together with force

Question 12

What determines the stream pattern of a periphery-deflected nozzle?

Answer 12

Position of the deflection stem and
exterior barrel
pg. 167

Question 13

A wide-angle deflection produces a ______ angle fog, and a narrow-angle defection produces a ______ angle fog.

Answer 13

Wide
Narrow

pg. 167

Question 14

How does an impinging stream nozzle form a fog pattern?

Answer 14

defects several jets of water together

pg. 168

Question 15

What is the result of water being discharged at angles to the direct line of discharge?

Answer 15

the reaction forces largely balance each other, reducing nozzle reaction

pg. 168

Question 16

Constant flow nozzles are designed to what?

Answer 16

flow a specific amount of water at a specific nozzle discharge pressure on all STREAM PATTERNS.

pg. 168

Question 17

Constant flow nozzles discharge the same volume of water regardless of what?

Answer 17

nozzle pattern setting

pg. 168

Question 18

What pressure are most constant flow nozzles intended to be operated at?

Answer 18

100 psi

pg. 168

Question 19

With an _________ nozzle, the selected flow remains constant whether a straight stream, narrow fog, or a wide fog is selected.

Answer 19

adjustable flow

pg. 169

Question 20

The automatic nozzle maintains the same ________ and ______ if the gallonage supplied to the nozzle is changed.

Answer 20

nozzle pressure

pattern

pg. 169

Question 21

What psi are most fog nozzles designed for?

Answer 21

100 psi

pg. 169

Question 22

What is the minimum flow setting for interior structural fire fighting?

Answer 22

95-100 gpm

pg. 169

Question 23

No matter how much the pump discharge pressure, an automatic nozzle maintains a constant nozzle pressure of approx. what psi?

Answer 23

100 psi

pg. 170

Question 24

What psi do high-pressure fog nozzles operate at?

Answer 24

800 psi

pg. 170

Question 25

What are high-pressure fog nozzles primarily used for?

Answer 25

wildland fire fighting

pg. 171

Question 26

What is the maximum amount of water that can safely flow through a handline nozzle?

Answer 26

350 gpm

pg. 171

Question 27

What is the term “master stream” applied to?

Answer 27

any fire stream that is too large to be controlled without mechanical aid.

pg. 171

Question 28

What psi are smoothbore master streams operated at?

Answer 28

80 psi

pg. 171

Question 29

What psi are fog master streams operated at?

Answer 29

100 psi

pg. 171

Question 30

What are the 4 basic types of master streams?

Answer 30

1. Monitor
2. Turret pipe
3. Deluge set
4. Elevated master stream

pg. 172

Question 31

How do monitors and deluge sets differ?

Answer 31

Monitor streams can change direction and angle while water is being discharged.

pg. 172

Question 32

How are broken streams created?

Answer 32

When water is forced through a series of small holes on the discharge end of the nozzle.

pg. 175

Question 33

What type of heat is a water curtain only effective in absorbing?

Answer 33

convected heat

pg. 176

Question 34

Piercing nozzles may be used to deliver what type of foam?

Answer 34

AFFF (aqueous film forming foam

pg. 176

Question 35

What GPM will a chimney nozzle generate at 100 psi?

Answer 35

1. 5-3 GPM

pg. 177

Question 36

What is the practical working limits for velocity of fire streams?

Answer 36

60-120 feet per second

pg. 178

Question 37

If greater reach and volume is needed from a solid stream handline, what can the nozzle pressure be raised to?

Answer 37

65 psi

pg. 178

Question 38

What is the rule of thumb for approximating nozzle reaction of a solid stream nozzle?

Answer 38

NR=Q/3

Q=flow in GPM

pg. 179

Question 39

What is the rule of thumb for approximating nozzle reaction of a fog stream nozzle?

Answer 39

NR=Q/2

Q= flow in GPM

pg. 179