Chapter 6 Hose Nozzles And Flow Rates

Question 1

What affects the condition of the stream as it leaves the nozzle:

Answer 1

Operating pressure nozzle design and adjustment, condition of the nozzle as well

Pg 193

Question 2

Until it reaches its destination the fire stream is influnced by:

Answer 2

Velocity, gravity, wind, and friction with the air

Pg193

Question 3

The fire service operates 3 types of nozzles to produce three basic fire streams, they are:

Answer 3

Solid, fog, and broken

Pg 193

Question 4

A solid stream is produced with a:

Answer 4

Fixed orifice and a smooth bore nozzle

Pg 194

Question 5

The flow and reach of a solid stream is determined by:

Answer 5

The pressure and size of the discharge orifice

Pg 194

Question 6

Solid stream nozzles should be operated at…..psi and master stream appliances should be operated at….. Psi

Answer 6

50/80

Pg 194

Question 7

Gpm formula is:

Answer 7

29.7 X d2 x sqroot of NP
D2 = diameter of the orifice in inches
Np is nozzle pressure in psi
Pg 195

Question 8

On fog nozzles a wide angle deflection produces:

A narrow angle deflection produces:

Answer 8

Wide fog pattern produced by wide deflection
Narrow fog pattern produced by a narrow deflection
Pg195

Question 9

A fog stream may be produced by deflection at the:

Answer 9

Periphery, by impinging jets of water, or a combination of these
Pg 198

Question 10

The position of the stem relative to the barrel will determine the:

Answer 10

Shape of the fog stream

Pg196

Question 11

Impinging stream nozzles most often provide a:

Answer 11

Wide angle fog pattern

Pg196

Question 12

THe reach of the fog stream is directly related to it:

Answer 12

Width, the size of the water particles, the wind, and the volume of water flowing
Pg197

Question 13

A constant flow nozzle is designed to flow:

Answer 13

A specific volume of water on all stream patterns at a specific nozzle discharge pressure
Pg197

Question 14

Most constant flow nozzles are designed to operat at a nozzle pressure of….. Psi however some nozzles may operate at….. Psi

Answer 14

100/50

Pg 197

Question 15

Selectable gallonage nozzles allow the firefighters operating the handline to select the:

Answer 15

Flow rate to suit fire and operating conditions

Pg 197

Question 16

Selectable gallonage nozzles are designed to flow the gallonage indicated at….. Psi nozzle pressure

Answer 16

100

Pg 198

Question 17

Automatic nozzles are a type of variable flow nozzle with the ability to:

Answer 17

Change patterns while maintaining the same nozzle pressure

Pg 198

Question 18

High pressure fog nozzles operate a pressures up to…. Psi and deliver a significant forward velocity but relatively low:

Answer 18

800 psi
Low water volume
Pg 199

Question 19

High pressure fog nozzles are best suited for……. Firefighting and only operate at… To …. Gpm

Answer 19

Wildland firefighting and operate at 8/15 gpm

Pg 199

Question 20

Nozzles for use on handlines may be …. Or ….. Or …… Design ranging in size from 3.4 inch to a 3 inch diameter hose nozzle. Generally …. Gpm is maximum flow for a handline

Answer 20

Solid, fog or broken stream
350 gpm
Pg 199

Question 21

Generally ….. Gpm is the maximum flow for a handline:

Answer 21

350

Pg 199

Question 22

Master stream nozles are capable of water flow in excess of 350 gpm and must be properly….. For safe operation:

Answer 22

Secured

Pg 199

Question 23

Master stream appliances are generally operated during incidents where handlines would be:

Answer 23

Ineffective, conditions require a defensive posture, or personnel are limited.

Pg 199

Question 24

Smooth bore streams are generally operated at …. Psi nozzle pressure while fog appliances are generally operated at…. Psi

Answer 24

80/100

Question 25

The three basic types of master streams appliances are:

Answer 25

Fixed, combination, portable: Fixed- deck guns permantely mounted to the apparatus Combination-can be used on a off the vehicle Portable- stored on apparatus and removed to use on scene

Question 26

Cellar nozzles are also referred to as:

Answer 26

Distributors Pg 200

Question 27

Piercing nozzles also called_________ are commonly used in:

Answer 27

Penetrating nozzles are used in aircraft fire fighting, car fires, or to apply water to voids, attics, or other areas inaccessible to standard fire streams Pg 201

Question 28

Chimney nozzles flow only________ gpm at 100 psi

Answer 28

1.5-3 gpm Pg 201

Question 29

Nozzle reaction:

Answer 29

The counterforce pushing back against firefighters operating the hoseline as water is discharging Pg 202

Question 30

Nozzle reaction formula:

Answer 30

NR=1.57 x d2 x np D= nozzle diameter in inches Np = nozzle pressure in psi Pg 203

Question 31

Nozzle reaction for fog stream nozzles formula:

Answer 31

NR= 0.0505 x q x sqroot NP Q= total flow through the nozzle in gpm Np = nozzle pressure in psi Pg 204