Chapter 6 - Hose Nozzles and Flow Rates Flashcards
To provide proper pressure and volume, a driver must be knowledgeable of the WHAT of each handline, nozzle and master stream appliance.
capabilities
__________ pressure, _______ design and adjustments as well as the condition of the nozzle _____ affect the condition of the stream as it leaves the nozzle.
- operating
- nozzle
- orifice
What does the water form as it leaves the orifice? A. fire stream B. pressure C. water line D. flow
A. fire stream
What can influence the fire stream until it reaches it’s destination? (4)
- v
- g
- w
- f with a
- velocity
- gravity
- wind
- friction with air
Optimum flow rate and discharge pressures that a driver insures are applied to each fire stream will help achieve WHAT at incident operations? A. maximum flow B. maximum efficiency C. maximum water resistance D. maximum help
B. maximum efficiency
How many types of nozzles that produce basic fire streams are there in the fire service?
3
What are the 3 types of nozzles in the fire service that produce 3 types of streams?
- solid
- fog
- broken stream
What kind of stream is produced with a fixed orifice and a smooth bore nozzle?
solid fire stream
What stream is described as tight with little spray or shower effect?
solid fire stream
Where can you find a solid fire stream? (2)
handlines and all types of master stream appliances
WHAT stream nozzle is designed so that the water flowing through the nozzle is gradually reduced until just before the orifice?
solid stream nozzle
A solid stream nozzle is designed so that the water flowing through the nozzle is gradually reduced until just before the orifice. What gives the solid stream nozzle fire stream is round shape at discharge?
when the nozzle becomes a cylindrical bore
A solid stream nozzle is designed so that the water flowing through the nozzle is gradually reduced until just before the orifice. At this point, the nozzle becomes a cylindrical bore and gives the water a round shape at discharge. The smooth waterway of the nozzle allows the stream to maximize what?
its effective reach
The nozzle _______ and ____ of the discharge determine the flow and reach of a solid stream.
- pressure
- size
Solid stream nozzles on handlines should generally be operated at a maximum pressure of _____ psi.
50
Solid stream nozzles on master streams should generally be operated at a maximum pressure of _____ psi.
80
Why might a driver need to determine the amount of water discharged from a solid stream nozzle?
A. perform friction loss calculations
B. determine pump discharge pressure
C. to test the water supply when a nozzle is attached to a HYDRANT
D. all of the above
D. all of the above
What is the formula to determine discharge rate?
GPM = _____ x d² x √__
GPM = 29.7 x d² x √NP
In the formula to determine discharge rate, GPM = 29.7 x d² x √NP, what does GPM mean?
DISCHARGE in gallons per minute
In the formula to determine discharge rate, GPM = 29.7 x d² x √NP, what does 29.7 represent?
a constant
In the formula to determine discharge rate, GPM = 29.7 x d² x √NP, what does d stand for?
diameter of the orifice in INCHES
In the formula to determine discharge rate, GPM = 29.7 x d² x √NP, what does NP stand for?
nozzle pressure in pounds per square inch (psi)
What 2 things must you know about a solid stream nozzle in order to determine water flow from the formula GPM = 29.7 x d² x √NP?
nozzle pressure
and
tip diameter
In order for a stream of water to be broken into finely divided particles, it must be driven against an WHAT with sufficient force to diffuse the water shatter the mass?
obstruction
What will determine the forward velocity of the stream of water as well as its pattern or shape? (fog nozzle stream)
the angle of deflection off the surface of the obstruction it encounters
A wide deflection of a fog nozzle stream will produce a narrow -angle fog pattern and a narrow deflection will produce a wide-angle fog pattern. TRUE or FALSE
false. wide deflection = wide-angle fog pattern
narrow deflection = narrow-angle fog pattern
What are the 3 types of fog nozzle patterns?
- straight stream
- wide fog
- narrow fog
What angles of water do a narrow fog pattern create?
15° - 45°
What angles of water do wide fog pattern create?
45° - 80°
What may be produced by deflection at the periphery, by impinging jets of water, or a combination of these methods?
a fog stream
What type of fog streams are produced by deflecting water around an inside circular stem in the nozzle? The water is then deflected by the exterior barrel of the nozzle. A. wide B. narrow C. periphery-deflected D. none of these
C. periphery-deflected stream
What will determine the shape of the fog stream in a periphery-deflected stream?
the position of the stem relative to the EXTERIOR barrel
What nozzle breaks water into fine, evenly divided particles by driving several jets of water together at an angle?
impinging stream nozzles
Impinging stream nozzles most often produce this type of fog pattern…(although a narrow pattern is possible)
wide-angle
Can impinging jets be used in some periphery deflected stream nozzles? YES OR NO
YES
What is directly related to its width, the size of water particles (droplets), the wind and the volume of water flow? (fog streams)
the reach of a fog stream
What kind of fog nozzle is designed to flow a specific volume of water on all stream patterns at a specific nozzle discharge pressure? A. adjustable gallonage B. automatic C. high pressure D. constant flow
D. constant flow
What kind of stream do most constant flow fog nozzles feature?
periphery-deflected stream
Are constant flow fog nozzles equipped with adjustable pattern ranges? YES or NO
YES
What will happen if you rotate the exterior of the barrel on a constant flow fog nozzle? (principle of operation)
change the pattern setting
During rotation to change the pattern of a constant flow fog nozzle, the space between the deflecting stem and the interior throat of the nozzle remains the _____, allowing for the discharge of a _____ gallonage of water on all pattern settings.
- same
- fixed
Most constant flow fog nozzles are designed to operate at a nozzle pressure of ___ psi. (but some are 50 or 75 psi)
100
Can some constant flow fog nozzles operate at a different pressure than the most common 100 psi? What flow if YES?
50 or 75 psi
What are the 4 types of fog nozzles?
- constant flow
- selectable gallonage
- automatic
- high pressure
What type of fog nozzle allows the firefighter operating the handline to select the flow rate to suit fire AND operating conditions?
selectable gallonage
On a selectable gallonage fog nozzle, the driver must supply the proper WHAT or the handline will not achieve the gallonage selected at the nozzle?
pressure
What pressure are MOST selectable gallonage fog nozzles designed to flow the gallonage indicated? (some are lower)
100 psi
Selectable gallonage nozzles and constant flow nozzles are similar in that when properly supplied, both discharge WHAT? A. predetermined gallonages B. fog streams C. water D. wide fog stream patterns
A. predetermined gallonages
When operating this type of fog nozzle, a driver sets its discharge gallonage with a specified range before use.
selectable gallonage fog nozzle
What in the department may specify predetermined discharge gallonage for selectable gallonage nozzles?
SOPs
SOPs may specify predetermined discharge gallonage for selectable gallonage nozzles. Who’s specifications are constant flow fog nozzles gallonages based on?
manufacturer of the nozzle
In order to properly calculate friction loss and determine an appropriate pump discharge pressure for a selectable gallonage nozzle, the driver must know what?
the gallonage setting (from the ff operating the handline)