Ch.7 Fire Hose Nozzles And Flow Rates

Question 1

What 2 things determine the flow and stream reach from a solid stream nozzle?

Answer 1

The nozzle pressure

The size and f the discharge opening

Question 2

What Psi should a solid stream nozzle be operated ad for a hand line and a Masters stream device?

Answer 2

Handling - 50 psi

Master stream- 80

Question 3

What is the formula for determining the amount of water being discharged from a solid stream nozzle?

Answer 3

GPM = 29.7 * d^2 * √NP

29.7 = constant 
d = diameter of orifice in inches
NP= nozzle pressure in psi

Question 4

The line bounding a rounded surface

Answer 4

Periphery

Question 5

A turning from a straight line or given course

Answer 5

Deflection

Question 6

To strike or dash about or against; Clashing with a sharp collision; to come together with Forrest

Answer 6

Impinge

Question 7

Name 4 things the reach of the fog stream is directly dependent on.

Answer 7

The width of the stream
The size of the water droplets
Wind
The amount of water flowing

Question 8

What is a constant flow nozzle designed to do?

Answer 8

Flow a specific amount of water at a specific nozzle discharge pressure on all stream patterns

Question 9

Constant flow nozzles discharge the same amount of water regardless of?

Answer 9

The pattern setting

Question 10

Most constant flow nozzles are designed to operate at a nozzle pressure of?

Answer 10

100psi

Question 11

This nozzle allows the firefighter to select a flow rate at the nozzle

Answer 11

Adjustable gallonage nozzle or manually adjustable nozzle

Question 12

Most of the adjustable gallonage nozzle are designed to operate at

Answer 12

100psi

Question 13

The minimum flow setting for interior structural firefighting is?

Answer 13

95-100gpm

Question 14

Automatic nozzles have the ability to

Answer 14

Maintain the same nozzle pressure

Question 15

If the Gallonage supplied to the automatic nozzle changes the automatic nozzle…

Answer 15

Maintains approximately the same nozzle pressure and pattern.

Question 16

How is the feature from the last card possible?

Answer 16

By a baffle that moves automatically varying the spacing between the baffle and the throat

Question 17

Name two ways you might know that your pump is starting to cavitate

And what can be done?

Answer 17

Pump starts to speed up or becomes erratic
Supply hose becomes soft and begins to collapse

Try backing off the throttle slightly

Question 18

No matter how much the pump discharge pressure is above, an automatic nozzle maintains a constant pressure of?

How does it do this?

Answer 18

100

By automatically enlarging it’s effective opening size (within the range of the nozzle) to match the flow.

Question 19

High pressure fog nozzles operate at pressures up to?

Answer 19

800 psi

Question 20

High pressure fog nozzles generally only flow how much gpm?

Answer 20

8-15 gpm

Question 21

Generally, what is the maximum amount of water that can safely flow through a hardline nozzle?

Answer 21

350 gpm

Question 22

Smoothbore and fog master streams operate at?

What gpm do master streams usually flow at?

Answer 22

Sb= 80 psi

Fog= 100 psi

350gpm or greater

Question 23

Name 4 basic master streams

Answer 23

Monitor
Turret pipe
Deluge set
Elevated master stream

Question 24

Which master stream can’t have the direction or angle changed while shooting water?

Answer 24

Deluge set

Question 25

This master stream is supplied by permanent piping from the pump

Answer 25

Turret pipe

Question 26

Stream direction and angle can be changed with this master stream while shooting water

Answer 26

Monitor

Question 27

If greater reach and volume on a smooth note nozzle is desired you can raise the nozzle pressure to ___ without it becoming unmanageable.

Answer 27

65 psi

Question 28

What is the formula for calculating the nozzle reaction for solid stream nozzles

Answer 28

NR= 1.57 * d^2 * NP

Question 29

Name the rule of thumb formula for getting an approximate amount of nozzle reaction for a solid stream nozzle.

Answer 29

NR= Q/3

Where Q is the total flow of water in gpm through the nozzle

So if your flowing 300 gpm out of a solid stream nozzle you probably have around 100 pounds of nozzle reaction.

Question 30

What is the formula for calculating the nozzle reaction for fog nozzles?

Answer 30

NR=0.0505 * Q * square root of NP

Where Q is the gpm and np is nozzle pressure

Question 31

Name the rule of thumb formula for getting an approximate amount of nozzle reaction for a fog stream nozzle.

Answer 31

NR= Q/2

So if your shooting 300 gpm than you have approximately 150 pounds of nozzle reaction