Chapter 11 Fire Hose Nozzles

Question 1

IFSTA definition of a handline nozzle

Answer 1

any nozzle designed primarily for attachment to a single movable hose line manually controlled and operated by one or more firefighters …equal or < 350 gpm

Question 2

what is the oldest style nozzles used by the fire service

Answer 2

solid stream nozzle

Question 3

the Freeman experiments produced what nozzle

Answer 3

the standard tip

Question 4

the ____ and the _____ determine the flow from a solid stream nozzle. both have size limitations

Answer 4

stream velocity

discharge opening

Question 5

what is the most flexible nozzle available to the fire service

Answer 5

the fog stream nozzle

Question 6

in general _____ and ____ are used for aggressive up close firefighting operations, while _____ are used for protecting exposures and firefighters

Answer 6

Straight stream, narrow fog stream

Wide Fog

Question 7

most modern fog stream nozzles operate on the principle of

Answer 7

periphery deflection

Question 8

what are the downsides of impinging stream nozzles

Answer 8

ineffective narrow fog patterns and straight streams

Question 9

what are the characteristics of a variable flow nozzle

Answer 9

produced different flow volumes depending on the particular variables of their design ( stream pattern, water pressure, supply line)

Question 10

what are the characteristics of a constant flow nozzle

Answer 10

constant flow nozzles flow a specific amount of water at a specific nozzle discharge pressure

Question 11

What is one of the most significant issues with the constant flow nozzle

Answer 11

if the pump operator fails to supply the rated nozzle pressure the flow will be less than the nozzle rating resulting in unsatisfactory stream…inflexible single flow at a NP, over pumping made unwieldy but no more water…

Question 12

what are constant flow volume nozzles commonly called today

Answer 12

automatic nozzles

Question 13

what are the characteristics of an automatic nozzle

Answer 13

automatic nozzle maintains constant nozzle pressure of approximately 100 psi, no matter how much the pump discharge pressure is above this figure. they do not also provide a constant volume under all conditions

Question 14

what’s a drawback to the automatic nozzle

Answer 14

with the pump operator is not supplying the minimum rated pressure the stream can look good but not be discharging sufficient water

Question 15

what’s another common name cellar nozzles

Answer 15

distributors

Question 16

how do piercing nozzles differ from cellar nozzles

Answer 16

piercing nozzles create their own hole, 3-6 ft hollow steel rod

Question 17

describe the operation of a chimney nozzle

Answer 17

chimney nozzle is a solid piece of brass or steel with small holes, 1.5-3 gpm attached to booster line and lowered down chimney

Question 18

what is the main drawback of water curtain

Answer 18

radiant heat is transmitted through the water curtain

Question 19

that counterforce of the velocity of water leaving the nozzle ( newtons third law of motion) is known as

Answer 19

nozzle reaction

Question 20

if extra reach is needed from a solid stream nozzle is acceptable to raise the pressure from 50 PSI to

Answer 20

65psi

Question 21

what does Q stand for

Answer 21

total water flow in GPM

Question 22

described the physical characteristics of a cellar nozzle

Answer 22

has a 90° bend

Question 23

what are the fire services commonly accepted practical working limits for velocity of the fire stream

Answer 23

60 - 120 ft./s
And since we can’t use velocity, psi ranges of nozzles are generally
20 - 100psi nozzle discharge pressure ranges