Smooth Bore NozzlesSmooth Bore Nozzlesvs.vs.

Combination NozzlesCombination Nozzles

Smooth Bore NozzlesSmooth Bore Nozzlesvs.vs.

Combination NozzlesCombination Nozzles

How is a fire stream best How is a fire stream best formed?formed?

How is a fire stream best How is a fire stream best formed?formed?

Smooth Bore NozzlesSmooth Bore NozzlesSmooth Bore NozzlesSmooth Bore Nozzles

Advantages:Advantages:SimpleSimple in design in designInexpensiveInexpensive

Disadvantages:Disadvantages: Has only Has only oneone correct operating pressure to correct operating pressure to

develop optimum velocity and reachdevelop optimum velocity and reachTip size must be changed to change flowTip size must be changed to change flowMust have Must have varietyvariety of tips for different flows of tips for different flowsNo fogNo fog capabilities capabilitiesNot effectiveNot effective for mechanical ventilation for mechanical ventilation

Advantages:Advantages:SimpleSimple in design in designInexpensiveInexpensive

Disadvantages:Disadvantages: Has only Has only oneone correct operating pressure to correct operating pressure to

develop optimum velocity and reachdevelop optimum velocity and reachTip size must be changed to change flowTip size must be changed to change flowMust have Must have varietyvariety of tips for different flows of tips for different flowsNo fogNo fog capabilities capabilitiesNot effectiveNot effective for mechanical ventilation for mechanical ventilation

Unequal Velocity of Unequal Velocity of Smooth BoreSmooth Bore

Unequal Velocity of Unequal Velocity of Smooth BoreSmooth Bore

Greater velocity at center of streamGreater velocity at center of streamLower velocity at outside of streamLower velocity at outside of streamCaused by side wall Caused by side wall turbulenceturbulenceCauses outside of stream to “peel” Causes outside of stream to “peel”

awayawayLess reachLess reach than straight stream than straight stream

from combination nozzlefrom combination nozzle

Greater velocity at center of streamGreater velocity at center of streamLower velocity at outside of streamLower velocity at outside of streamCaused by side wall Caused by side wall turbulenceturbulenceCauses outside of stream to “peel” Causes outside of stream to “peel”

awayawayLess reachLess reach than straight stream than straight stream

from combination nozzlefrom combination nozzle

Side Wall FrictionCenter "core" at higher velocity

than outer circle of stream.

Stream expansion begins upon exiting tip

Equal Velocity of Combination NozzleEqual Velocity of Combination NozzleEqual Velocity of Combination NozzleEqual Velocity of Combination Nozzle

EqualEqual velocity across stream velocity across streamPartial Partial vacuum vacuum within the pattern focuses stream a short within the pattern focuses stream a short

distance from the nozzledistance from the nozzleRe-converged stream has a Re-converged stream has a uniformuniform cross-sectional velocity cross-sectional velocityTighter stream with Tighter stream with more reach more reach than smooth borethan smooth bore

EqualEqual velocity across stream velocity across streamPartial Partial vacuum vacuum within the pattern focuses stream a short within the pattern focuses stream a short

distance from the nozzledistance from the nozzleRe-converged stream has a Re-converged stream has a uniformuniform cross-sectional velocity cross-sectional velocityTighter stream with Tighter stream with more reach more reach than smooth borethan smooth bore

Partial Vacuum

Water exits nozzle at EQUAL velocity and pressure

Focused Point

Equal Velocity of Combination NozzleEqual Velocity of Combination Nozzle

Partial Vacuum

Water exits nozzle at EQUAL velocity and pressure

Focused Point

At Equal Flows...At Equal Flows...Which stream has more reach?Which stream has more reach?

At Equal Flows...At Equal Flows...Which stream has more reach?Which stream has more reach?

At Equal Flows...Combination Nozzle Reaches Farther

Than Smooth Bore Nozzle

At Equal Flows...Combination Nozzle Reaches Farther

Than Smooth Bore Nozzle

Straight Stream FromStraight Stream FromCombination Nozzle...Combination Nozzle...Straight Stream FromStraight Stream FromCombination Nozzle...Combination Nozzle...

Because of higher nozzle Because of higher nozzle pressure & velocity than pressure & velocity than smooth bore, combination smooth bore, combination nozzle stream nozzle stream hits harder hits harder

Because of higher nozzle Because of higher nozzle pressure & velocity than pressure & velocity than smooth bore, combination smooth bore, combination nozzle stream nozzle stream hits harder hits harder

Not hollowNot hollow as seen by as seen by Pitot gauge pressure Pitot gauge pressure reading at focal pointreading at focal point

Impact Force of StreamImpact Force of StreamImpact Force of StreamImpact Force of Stream

FF = M V = M V FForceorce == M Mass timesass times V Velocityelocityoror WVWV

gg

MM = = MMass of water /unit of timeass of water /unit of timeVV = = VVelocity of water /unit of timeelocity of water /unit of time

WW = = WWeight of water /unit of timeeight of water /unit of timegg = = GGravitational constant ravitational constant 32.2 ft/sec32.2 ft/sec22

FF = M V = M V FForceorce == M Mass timesass times V Velocityelocityoror WVWV

gg

MM = = MMass of water /unit of timeass of water /unit of timeVV = = VVelocity of water /unit of timeelocity of water /unit of time

WW = = WWeight of water /unit of timeeight of water /unit of timegg = = GGravitational constant ravitational constant 32.2 ft/sec32.2 ft/sec22

F =F =F =F =

Impact Force of 150 GPM Stream...Impact Force of 150 GPM Stream...Impact Force of 150 GPM Stream...Impact Force of 150 GPM Stream...

WVWV 32.2 ft./sec.32.2 ft./sec.22

W = W = 150 GPM 150 GPM xx 8.34 lb./gal 8.34 lb./gal == 1251 lb./min. 1251 lb./min.W = W = 1251 lb./min. 1251 lb./min. divideddivided by 60 sec./min. by 60 sec./min.W = 20.85W = 20.85 lb./sec. lb./sec.

VV == VVelocity elocity @@ 150 GPM 150 GPM

7/8” Smooth Bore @ 44 psi 7/8” Smooth Bore @ 44 psi = 80 ft./sec. (54.5 MPH)= 80 ft./sec. (54.5 MPH)Combination Nozzle @ 75 psiCombination Nozzle @ 75 psi = 106.9 ft./sec. (72.9 MPH) = 106.9 ft./sec. (72.9 MPH)Combination Nozzle @ 100 psiCombination Nozzle @ 100 psi = 121 ft./sec. (82.5 MPH) = 121 ft./sec. (82.5 MPH)

WVWV 32.2 ft./sec.32.2 ft./sec.22

W = W = 150 GPM 150 GPM xx 8.34 lb./gal 8.34 lb./gal == 1251 lb./min. 1251 lb./min.W = W = 1251 lb./min. 1251 lb./min. divideddivided by 60 sec./min. by 60 sec./min.W = 20.85W = 20.85 lb./sec. lb./sec.

VV == VVelocity elocity @@ 150 GPM 150 GPM

7/8” Smooth Bore @ 44 psi 7/8” Smooth Bore @ 44 psi = 80 ft./sec. (54.5 MPH)= 80 ft./sec. (54.5 MPH)Combination Nozzle @ 75 psiCombination Nozzle @ 75 psi = 106.9 ft./sec. (72.9 MPH) = 106.9 ft./sec. (72.9 MPH)Combination Nozzle @ 100 psiCombination Nozzle @ 100 psi = 121 ft./sec. (82.5 MPH) = 121 ft./sec. (82.5 MPH)

F =F =F =F =

Comparison of Velocity... @ 150 GPM

Comparison of Velocity... @ 150 GPM

Nozzle Type Nozzle PressureVelocity

7/8” Smooth Bore 44 psi 54.5 mph

Combination Nozzle 75 psi 72.9 mph

Combination Nozzle 100 psi 82.5 mph

Nozzle Type Nozzle PressureVelocity

7/8” Smooth Bore 44 psi 54.5 mph

Combination Nozzle 75 psi 72.9 mph

Combination Nozzle 100 psi 82.5 mph

7/8” Smooth Bore @ 44 psi7/8” Smooth Bore @ 44 psi 20.85 lb./sec. 20.85 lb./sec. xx 80 ft./sec. 80 ft./sec. 32.2 ft./sec.32.2 ft./sec.22

Combination Nozzle @ 75 psi Combination Nozzle @ 75 psi 20.85 lb./sec. 20.85 lb./sec. xx 106.9 ft./sec. 106.9 ft./sec. 32.2 ft./sec.32.2 ft./sec.22

Combination Nozzle @ 100 psi Combination Nozzle @ 100 psi 20.85 lb./sec. 20.85 lb./sec. xx 121 ft./sec. 121 ft./sec. 32.2 ft./sec.32.2 ft./sec.22

7/8” Smooth Bore @ 44 psi7/8” Smooth Bore @ 44 psi 20.85 lb./sec. 20.85 lb./sec. xx 80 ft./sec. 80 ft./sec. 32.2 ft./sec.32.2 ft./sec.22

Combination Nozzle @ 75 psi Combination Nozzle @ 75 psi 20.85 lb./sec. 20.85 lb./sec. xx 106.9 ft./sec. 106.9 ft./sec. 32.2 ft./sec.32.2 ft./sec.22

Combination Nozzle @ 100 psi Combination Nozzle @ 100 psi 20.85 lb./sec. 20.85 lb./sec. xx 121 ft./sec. 121 ft./sec. 32.2 ft./sec.32.2 ft./sec.22

F =F = = 51.8 lb. Force = 51.8 lb. Force

F =F = = 69.2 lb. Force = 69.2 lb. Force

F =F = = 78.3 lb. Force = 78.3 lb. Force

Comparison of Impact Force...Comparison of Impact Force... @ 150 GPM @ 150 GPM

Comparison of Impact Force...Comparison of Impact Force... @ 150 GPM @ 150 GPM

Comparison of Nozzle Reaction Force... @ 150 GPM

Comparison of Nozzle Reaction Force... @ 150 GPM

Nozzle Type @ Nozzle Pressure Reaction Force

7/8” Smooth Bore @ 44 psi 52.8 lb. force

Combination Nozzle @ 75 psi 67.5 lb. force

Combination Nozzle @ 100 psi 79.2 lb. force

Nozzle Type @ Nozzle Pressure Reaction Force

7/8” Smooth Bore @ 44 psi 52.8 lb. force

Combination Nozzle @ 75 psi 67.5 lb. force

Combination Nozzle @ 100 psi 79.2 lb. force

Impact Force & Velocity...Impact Force & Velocity...

Combination nozzle has Combination nozzle has higher higher velocityvelocity

Smooth Bore has Smooth Bore has lower velocitylower velocityHigher velocity with same flow Higher velocity with same flow

equals equals more forcemore forceTherefore, Therefore, harder hittingharder hitting stream is stream is

typically realized from typically realized from combination combination nozzle nozzle at higher pressureat higher pressure

Combination nozzle has Combination nozzle has higher higher velocityvelocity

Smooth Bore has Smooth Bore has lower velocitylower velocityHigher velocity with same flow Higher velocity with same flow

equals equals more forcemore forceTherefore, Therefore, harder hittingharder hitting stream is stream is

typically realized from typically realized from combination combination nozzle nozzle at higher pressureat higher pressure

Stream Impact Testing...Stream Impact Testing...Stream Impact Testing...Stream Impact Testing...

Flow of 160 GPM Flow of 160 GPM (typical of smooth (typical of smooth bore & combination bore & combination nozzles)nozzles)

Differing distances Differing distances and target sizes usedand target sizes used

Flows & Pressures Flows & Pressures closely monitored for closely monitored for valid test resultsvalid test results

Flow of 160 GPM Flow of 160 GPM (typical of smooth (typical of smooth bore & combination bore & combination nozzles)nozzles)

Differing distances Differing distances and target sizes usedand target sizes used

Flows & Pressures Flows & Pressures closely monitored for closely monitored for valid test resultsvalid test results

Results:Results: Harder hitting, farther reaching stream Harder hitting, farther reaching stream from combination nozzles because of higher from combination nozzles because of higher

stream velocitystream velocity

Results:Results: Harder hitting, farther reaching stream Harder hitting, farther reaching stream from combination nozzles because of higher from combination nozzles because of higher

stream velocitystream velocity