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Energy Analysis of Pipes and Fittings
Clifford Hansel Fel A. Sagarino1, Eros Tristan A. Jabines2, and Dewey Siong
Abstra!t" Losses are always present in a piping system and this should be taken into
consideration. The experiment deals with the losses on pipes and fittings. The head losses in the
system are observed as a drop in the hydraulic and energy grade line. When fluid flows through
any passage which in the experiment it passes through pipes and fittings there is hydraulic drop
due friction and some restrictions and this head losses can be determined by the use of
manometers installed along the piping system. Losses can be read as the change of height of the
fluid seen from the manometer. The head of the tank is maintained at a constant to achieve.
Corresponding pipe coefficients (K are determined by getting the volume flow rate hence
obtaining the velocity of the fluid along the pipes. The K values of the similar and identical
fittings calculated is used to calculate the head loss for the piping system that do not have
manometers installed in similar and identical fittings. Lastly! the hydraulic and energy grade line
of each pipe is plotted in a graph to observe the head losses along the pipes.
A#t$or %eywords""ressure drop# "ipe friction# $ischarge loss# Losses in "ipe %ittings#
&ydraulic grade# 'nergy grade line# anometer# "ie)ometer
*************************
+,tudent! $epartment of echanical 'ngineering! -niversity of ,an Carlos! Cebu City!
"hilippines. 'mail/ chf*saga012yahoo.com
0,tudent! $epartment of echanical 'ngineering! -niversity of ,an Carlos! Cebu City!
"hilippines. 'mail/ eros3abines2yahoo.com
4,tudent! $epartment of echanical 'ngineering! -niversity of ,an Carlos! Cebu City!
"hilippines. 'mail/d3ohn*+12yahoo.com
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mailto:[email protected]:[email protected]7/23/2019 Pipes and Fittings (1)
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&ntrod#!tion
%luid experiences losses along a piping system and is taken into consideration in piping
construction. "ipe losses happens along the pipe length and pipe fittings which includes the gate
valve. The losses in pipe length may be computed using the $arcyWeisbach e5uation("otter!
06+0. 7ther cause of this losses may be due to sudden expansion and contraction of the flow of
the fluid (Cengel! 0668! installations of orifice! venture flow meters! rotameter! and flow no))les
(Cimbala! 0661! installations of pipe fittings ('sposito! 0666! and the pressure losses due to
some leaks along the fittings(orse! +9:4.The list can contribute to the decreasing of the
hydraulic and energy grade line wherein the greater the slope upward! the greater the loss per
unit length (Kundu! 066;. "iping systems installations and materials used must follow the
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>eynolds number which the properties of the fluid flowing through the pipe and pipe
characteristics are parameters used to determine the friction factor with the use of the moody
diagram. With the >eynolds number! it will be utili)e which ultimately solve the losses along
pipes by the use of the $arcyWeibach e5uation ("otter! 06+0. The velocity head plays a key
role in establishing the energy grade line of the pipeline. &ydraulic grade line is defined as
elevation head plus pressure head and energy grade line is the hydraulic grade line plus the
velocity head (White! 066;.
E'peri(ental )et$ods
?n doing the experiment! some safety ha)ards were observe to safeguard the student. @efore
doing the experiment a centrifugal pump! as shown in %ig. 0 is re5uired to provide a steady flow
of water to the tank. The centrifugal pump re5uires an axial pump at is used to deliver water to
the centrifugal pump as in a method of priming. ?nitially air pocketswere removed from the
centrifugal pump when the axial pump is delivering water to it! if not done! this will cause
damage to the pump by virtue of cavitation(Wright! +999."riming was needed for the
centrifugal pump because pumping air will cause the centrifugal pump to reach speed of Arun
awayB that will lead to overheating('sposito! 0666. When there is a steady flow of water
coming out of the centrifugal pump gate valve the axial pump is turned off.
The experiment proper was started by choosing a tank head by turning the crank head control to
+66cm from the cylinder reading. Water was then operated to flow to a single pipe line at a time.
%low is measured by the use of a 00 liter bucket with the help of a timer. The method must be
done with two person and the velocities of each pipe flow were then calculated. 'ach pipe fitting
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were studied by the use of manometers in between the fitting but some do not have manometers
to determine the head loss along it. The difference in manometer height is recorded to be the
head loss due to the pipe fitting and in some connections because of the pipe length. The head
loss caused by the fitting may be computed by this e5uation/
hLfitting=K V
2
2g (+
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The relative roughness! ! is assumed to be 6.66+: for galvani)ed pipe. Re is the >eynolds
number.
The measured and calculated data of the experiment are shown on Tables +8.
,ample Calculations/
The K values of the =ate valve at pipe line +at tank head of +66cm is calculated as follows/
(K V2
2g)gatevalve1=HLGate valve1 (4
( K(70.35s )
2
2(32.2fts2 )(12ft))gatevalve1=2 (1KGatevalve 1=KGatevalve2=KGatevalve3=0.3123 (:
,ince the other gate valve head loss cannot be measured! they may be calculated as follows/
12
2(32.2ft
s2)()=1.2119
0.3123(54.7625 s)2
HL Gatevalve2=
(8
12
2(32.2ft
s2)()=0.2838
0.3123(26.5 s)2
HLGate valve3=
(D
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The experiment performed shows that each fitting corresponds to a head loss that is uni5ue to
each other. These losses can be termed as the decrease energy of the piping system along the
pipes and fittings. This is stated in (Kundu! 066; that when the slope of the &ydraulic or 'nergy
grade line increases with respect to the pipe length and fittings. The head loss also increases
corresponding to the increase in velocity. This observation is observed in ("otter! 06+0 that head
loss is proportional to the average velocity. This is due to the decrease in velocity since velocity
is directly proportional to the losses in the fitting.
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g E gravitational constant! 40.4 inGs0
HV E Felocity &ead! in
*eferen!es
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Kundu! ". K. (066;. %luid mechanics.
orse! %. (+9:4. "ower "lant 'ngineering
"otter! . C. (06+0. echanics of %luids. Cengage learning
White! %. . (066;. %luid mechanics
Wright! T. (+999. %luid achinery/ "erformance!
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%ig 0. 'xperimental ,et up
%ig 4. List of coefficient of loss K in "ipe fittings
%ig. 1. &ydraulic and 'nergy grade line of "ipeline + ('xperimental and Theoretical vs. ,ection
%ig. :. &ydraulic and 'nergy grade line of "ipeline 0 ('xperimental and Theoretical vs. ,ection
%ig. 8. &ydraulic and 'nergy grade line of "ipeline 4 ('xperimental and Theoretical vs. ,ection
Table +/ easured and computed data on "ipeline + at Tank &ead of +66cm
%low rate (in4Gs 0D9.D+4
$iameter of outlet! in 0.0:
velocity at outlet! inGs D6.4:
&ead of outlet! in
"ipeline +
,ection number &ead loss! in
+ 0
0 +9.;:+D
4 4
1 06.6;0:
: 1.9:
8 +4.;:
D 4
; 4.180:
9 4+6 +4.D418
Table 0/ Theoretical data on "ipeline +
"ipeline + %ittings &ead loss! in %low rate (in4Gs 0D9.D+4
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=ate
valve +.6;;D $iameter of outlet! in 0.0:
-nion 6.0:8+D velocity at outlet! inGs D6.4:
%ittings 6.0:8+D &ead of outlet! in
1: bend 0.01+:
1: bend 0.01+:
Table 4/ easured and computed data on "ipeline 0 at Tank &ead of +66cm
%low rate (in4Gs 0+D.D1
$iameter of outlet! in 0.0:
velocity at outlet! inGs :1.D80:
&ead of outlet! in
"ipeline 0
,ection number &ead loss! in
+ +.0++9
0 6.8+:4 48.4
1 +.;D8
: +.;+D;
8 1.48D
D 4
; +.;D8
9 +6.4D1
+6 +.:8;4
Table 1/ Theoretical data on "ipeline 0
"ipeline 0 %ittings &ead loss! in %low rate (in4Gs 0+D.D1
=ate valve 6.8:9D $iameter of outlet! in 0.0:
%low meter 0D.+810 velocity at outlet! inGs :1.D80
:
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-nion 6.+::0 &ead of outlet! in
%ittings 6.+::0
96 bend 0.9+6:
Table :/ easured and computed data on "ipeline 4 at Tank &ead of +66cm
%low rate (in4Gs 40.:++4:
$iameter of outlet! in +.0:
velocity at outlet! inGs 08.:&ead of outlet! in
"ipeline 4
,ection number &ead loss! in
+ 6.0;4;
0 6.D:0
4 81
1 6.0;:+8
: 6.816D
8 6.+D:6
D ;.:; 0.0::4:
9 8.109
+6 6.:D64
Table 8/ Theoretical data on "ipeline 4
"ipeline 4
%ittings &ead loss! in %low rate (in4Gs
40.:++4
:
=ate valve 6.040: $iameter of outlet! in +.0:
-nion 6.6:1D
velocity at outlet! inGs 08.:
&ead of outlet! in
%low meter 8.48
96 bend +.60:;
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%ig +. Commonly used "ipe %ittings
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%ig 0. 'xperimental ,et up
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%ig 4. List of coefficient of loss K in "ipe fittings
Courtesy of engineering toolbox
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Experimental (HGL)
Theoretical (HGL)
Experimental (EGL)
Theoretical (EGL)
%ig. 1. &ydraulic and 'nergy grade line of "ipeline +
('xperimental and Theoretical vs. ,ection
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Experimental(HGL)
Theoretical(HGL)
Experimental(EGL)
Theoretical(EGL)
%ig. :. &ydraulic and 'nergy grade line of "ipeline 0
('xperimental and Theoretical vs. ,ection
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Experimental(HGL)
Theoretical9HGL)
Experimental(EGL)
Theoretical(EGL)
%ig. 8. &ydraulic and 'nergy grade line of "ipeline 4
'xperimental and Theoretical vs. ,ection
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