smooth bore nozzles vs. combination nozzles how is a fire stream best formed?
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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