Transcript 200 GPM - Renton Fire & Emergency Services

Hydraulics

Theory and application allowing
control and use of fluid pressure
Hydraulic Theories

Understanding the theoretical and
practical application of hydraulics essential
for pump operation. The study of fire
ground hydraulics is divided into two
categories, theoretical and rule of thumb.
The driver/operator must be able to apply
both.
Elements of Hydraulic Calculation
Nozzle Loss
Attack Line Loss
Elevation Loss
Manifold/ Appliance
Standpipe Loss
Supply Line Loss
Terminology in Friction Loss
Formulas






NP FL AL EL TPL NPDP
Nozzle Pressure
Friction Loss
Appliance Loss
Elevation Pressure
Total Pressure Loss
- Net Pump Discharge Pressure
Theoretical

In the classroom and non-emergency
activities of the fire department,
mathematical equations are used to
calculate the flow characteristics of our
equipment and systems. This method of
calculation is commonly referred to as
“Theoretical Hydraulics”. By using
mathematical formulas, a relatively
accurate calculation of the total probable
friction loss is obtained. This method is
normally more accurate than Rule of
Thumb.
Theoretical Formula
There are many formulas and methods for
figuring friction loss but the Renton Fire
Department has adopted the following for
use in its training program.
2
FL = CQ L
Where
Q = Quantity
C = Coefficient
L = Length in 100’s
Hose Coefficients
Coefficients for Renton Fire Department
hose:
1¾“
2½“
3½“
5“
C = 15.5
C=2
C = 0.34
C = 0.08
Siamesed Hose Lines Coefficients
Two 2 ½”
Three 2 ½”
0.5
0.22
Rule of Thumb

On the fire ground, the driver/operator
normally works with a condensed and
simplified application known as “Rule of
Thumb Hydraulics”. Rule of thumb
hydraulic formulas are a chosen series of
fixed, rounded values that can be applied
to an operation sequentially to build a
water delivery system.
Rule of Thumb
Fixed Rounded Value Examples
2 ½” Combination Nozzle
250 GPM
1 ¾” Combination Nozzle
125 GPM
1 ¾” Hose
25 psi FL / Section
2 ½” Hose
06 psi FL / Section
Master Stream Devices
25 psi FL
Appliances (Wye etc…)
0 FL @ <350 gpm
Appliances (Wye etc…)
10 psi FL @ > 350 gpm
Elevation
05 psi FL / Floor
Appliance Pressure Loss
< 350 gpm no calculated loss
> 350 gpm 10 psi per appliance
25 psi for all master stream
devices
25 psi for all standpipes
Nozzles and Tips
Types of Nozzles
Broken Stream
Solid Stream
Periphery Deflected
(Combination )
Impinging stream
(Naval type)
Nozzle Design
The purpose of any nozzle is to provide a restriction of
the flow to build pressure. This restriction, and subsequent
created pressure, provides a usable velocity to project the
water stream. For any one flow, there is one correct nozzle
size (restriction) to develop the optimum pressure and
velocity.
Restriction
Designed Nozzle Pressure
Smooth Bore Nozzle - Hand line
- 50 PSI
½” thru 1 ¼” nozzles
Smooth Bore Nozzle - Master Stream
- 80 PSI
nozzles 1 ¼” and over
Fog Nozzle
all nozzles
- 100 PSI
Solid Stream Characteristics
The mechanical characteristics of a solid
stream nozzle produce a compact stream that
has a higher mass and velocity. These features
typically yield better reach and penetration.
Solid Stream Composition
The interior diameter of the nozzle is gradually
decreased until it reaches a point just short of
the outlet. At this point the straight cylindrical
bore has a length from 1 to 1 ½ times its
bore, this area is known as the stream shaper
Solid Stream Mechanics
Water flowing through a nozzle is subject to the
same physical principals of friction as hose. The net
effect of friction in a solid stream nozzle is the
creation of a laminar flow. The center of the flowing
stream is faster than the edge. This creates a
peripheral turbulence that is visible after the stream
exits the nozzle.
Solid Stream - Formulas

Discharge Volume:


29.7 x D2 x
NP
Nozzle Reaction:

1.57 x D2 x NP
Fog Stream - Characteristics
A stream of water remains in a solid mass, not
losing continuity until it strikes an object, is
overcome by gravity or is changed by friction
with the air. Fog stream nozzles are designed
around this theory and are commonly called
broken stream appliances
Fog Stream - Composition
All fog streams are of two mechanical
types, Periphery-deflected or impinging
stream. The shape and reach of a fog
stream are results of the appliance shape
and the velocity/pressure of the water.
Impinging Stream
Impinging Stream fog patterns are produced by driving jets
of water together at a set angle to break the streams into
finely divided particles. These appliances generally
produce wide angle fog patterns.
Periphery-Deflected
Periphery –Deflected streams are
produced by deflecting water from the
periphery of an inside circular stem to
the inner circumference of the
adjustable barrel. The position of the
barrel varies the shape of the stream
from a light fog to a straight stream.
There are two common types of these
nozzles, automatic and non-automatic.
Periphery-Deflected, Automatic
Automatic Periphery-Deflected
nozzles have a spring loaded
baffle assembly that reacts to
incoming pressure. The baffle is
calibrated to function at 100 PSI.
The model illustrated has a
sliding valve which allow the
firefighter to meter the flow at the
nozzle.
Periphery-Deflected, Automatic
When pressure at the
nozzle is less, the baffle
moves in to maintain the
pattern. When the
pressure is greater than
100 PSI the baffle moves
out to allow more volume
and minimize the nozzle
reaction.
Periphery-Deflected, Automatic
Task Force Tip nozzles have a
slide valve assembly that allows
the water flow at the tip to be
metered. By using this valve
design, the nozzle has a
smoother flow and less
turbulence. Note the valve
position in the illustrations.
Fog Stream - Formulas

Nozzle Reaction:

0.0505 x Q x
NP
Slide Valve Operation
Slide Valve
Gated ½ Way
Ball Valve Operation
Ball Valve
Gated ½ Way
Nozzle reaction is the force that a firefighter feels when he
is operating a nozzle. Nozzle reaction is primarily a result
of discharge pressure at the nozzle. If the nozzle
pressure is lowered, the firefighter will note a
corresponding decrease in the nozzle reaction.
Nozzle Reaction
To calculate the nozzle reaction use the following formulas, note same
flows can often be developed at a far lower nozzle reaction in solid
stream nozzles. Traditional thought is that solid bore hand lines should
be pumped at 50 psi. Any nozzle pressures higher than 65 psi
becomes unmanageable. In the following table review and compare
the reaction force of various fire streams.

Nozzle Reaction:


1.57 x D2 x NP
Nozzle Reaction:

Solid Stream
0.0505 x Q x
NP
Fog Stream
Handline Nozzle Reaction Chart
125 GPM
3/4” tip @ 56 NP
combination @ 100 NP
=
=
49 NR
63 NR
7/8” tip @ 44 NP
combination @ 100 NP
=
=
53 NR
76 NR
7/8” tip @ 60 NP
combination @
=
=
72 NR
88 NR
1” tip @ 46 NP
combination @ 75 NP
combination @ 100 NP
=
=
=
72 NR
87 NR
101 NR
1” tip @ 72 NP
1-1/8” tip @ 50 NP
combination @ 100 NP
=
=
=
113 NR
99 NR
126 NR
1” tip @ 100 NP
1-1/8” @ 64 NP
combination @ 100 NP
=
=
=
157 NR
127 NR
152 NR
1” tip @ 120 NP
1-1/8” tip @ 75 NP
1-1/4” tip @ 50 NP
combination @ 100 NP
=
=
=
=
188
149
123
164
150 GPM
175 GPM
100 NP
200 GPM
250 GPM
300 GPM
325 GPM
NR
NR
NR
NR
Theoretical Formula
2
FL = CQ L
Where
Q = Quantity
C = Coefficient
L = Length in 100’s
Hose Coefficients
Coefficients for Renton Fire Department
hose:
1¾“
2½“
3½“
5“
C = 15.5
C=2
C = 0.34
C = 0.08
Siamesed Hose Lines Coefficients
Two 2 ½”
Three 2 ½”
0.5
0.22
125 gpm
125 gpm
2 ½” – 400 ‘
1 ¾” – 150’
1 ¾” – 200’
Answer
100 psi NP
48 psi FL 1 ¾”,
50 psi FL 2 ½”,
198 psi NPDP
200’
400’
(36 psi FL 1 ¾”, 150’ plus 5 psi
elevation is less than 200’. Pump to
the highest friction loss)
200 gpm
250 gpm
200’ of 5”
200’ 1 ¾”
200’ 2 ½”
Answer
100 psi NP
5
psi elevation
124 psi 1 ¾”, 200’
10 psi appliance loss (>350gpm)
3.24 psi 5”, 200’
242.24 psi NPDP
(2 ½” FL is 25 psi, pump to the highest
loss)
600 GPM
2 ea. 2 ½” 50’
1 ½” ti
200’ of 5”
2 ½” 200’
250 GPM
Answer
100 psi NP
25 psi FL, 2 ½”
10 psi AL
11.56 psi FL 5”
146.56 psi NPDP
(NP 80 psi, 1 ½” tip 600 gpm / 25 psi FL
Masterstream / 9 psi FL 2 ½” Siamese
= 114 psi. Pump to the highest loss. Gate
down the Master stream if necessary)
1 ¼”
Solid Bore
1 ¾” 150’
200 gpm
250’ 2 ½’
125
gpm
2 ½’” 200’
250 gpm
1 ¾” 200’
Answer
100 psi NP
2 ½” 25 psi FL
1 ¾” 200 gpm, 93 psi FL
1 ¾” 125 gpm, 48.4 psi FL
50 psi
2 ½” with 1 ¼” 328 gpm, 53.7 psi
193 psi NPDP, pump to the
highest friction loss
150 gpm
200’
1 ¾”
40’
Answer
100
17.36
69.75
187.11
psi NP
psi EL (.434/ft)
psi FL
psi NPDP
200’ 1 ¾”
100” Siamesed 2 ½”
150 gpm
Answer
100 psi NP @ 150 gpm
69.75 psi FL 1 ¾”, 200’
34.72 psi EL (.434 psi X 8 floors above the 1st)
25 psi FL Standpipe
01.125 psi FL Siamesed 2 ½”
230.59 psi NPDP
200’ of 1 ¾” @ 200 gpm
100’ of 2 ½”
Answer
100 psi NP @ 150 gpm
124 psi FL 1 ¾”, 200’
34.72 psi EL (.434 psi X 8 floors above the 1st)
25 psi FL Standpipe
08 psi FL Siamesed 2 ½”
291.72 psi NPDP
What single adjustment could you make to cut the
friction loss by NPDP by 25 psi?
150’ of 2 ½”
150’ of 2 ½”
2 ea. / 100’ of 2 ½”
250 GPM
150’ of 1 ¾”
180 GPM
Answer
100 psi NP @ 180 gpm
75.33 psi FL 1 ¾”, 150’
9.72 psi FL – 2 ½”, 150’
26.04 psi EL (.434 psi X 6 floors above the 1st)
25 psi FL Standpipe
09.25 psi FL Siamesed 2 ½”
245 psi NPDP
The 2 ½” NPDP was 187.72 pump to the highest friction loss.
How would the excess pressure be dealt with in this line?