MODELING OF THERMODYNAMIC HEATING OF WATER THROUGH
HYDRAULIC HEAT LOAD AND PRESSURE DROP
A Thesis
Presented to the faculty of the Department of Mechanical Engineering
California State University, Sacramento
Submitted in partial satisfaction of
the requirements for the degree of
MASTER OF SCIENCE
in
Mechanical Engineering
by
Edward Howard Little III
SPRING
2014
MODELING OF THERMODYNAMIC HEATING OF WATER THROUGH
HYDRAULIC HEAT LOAD AND PRESSURE DROP
A Thesis
by
Edward Howard Little III
Approved by:
__________________________________, Committee Chair
Kenneth Sprott, Ph. D.
__________________________________, Second Reader
Timothy Marbach, Ph. D.
____________________________
Date
ii
Student: Edward Howard Little III
I certify that this student has met the requirements for format contained in the University format
manual, and that this thesis is suitable for shelving in the Library and credit is to be awarded for
the thesis.
__________________________, Graduate Coordinator ___________________
Akihiko Kumagai, Ph. D.
Date
Department of Mechanical Engineering
iii
Abstract
of
MODELING OF THERMODYNAMIC HEATING OF WATER THROUGH
HYDRAULIC HEAT LOAD AND PRESSURE DROP
by
Edward Howard Little III
Heat-loading on working fluids such as those used on Hydraulic and Braking systems
have been considered to cause a negative effect due to performance inefficiencies and
pressure drops brought on by designed features such as pressure regulators and relief
valves. For this type of working systems the negative effect causes toward the working
fluid are in the form of heat, which if not properly regulated can cause a degradation to
the performance (reduction of working force) of the hydraulic system, as well as the
breakdown of the hydraulic fluid, and an increase in the wear to critical components such
as seals, bearings (as used in pumps and valves that could lead to premature failure of the
hydraulic system. Normally, this heating effect is addressed by the integration of devices
such as a heat exchanger or properly sized fluid reservoirs into the hydraulic system. By
doing so this effectively dissipates or reduces the amount of thermal energy residing in
the heated fluid. Such preventive methods help maintain a sufficient operating
temperature range within the system, protecting components. However, what if this
negative heating effect that occurs within hydraulics systems could be harnessed, even
iv
promoted to produce a positive product in the form of raising the temperature in water
such as could used to design an instantaneous hot water heater system? The work laid out
in this thesis is intended to evaluate if the use of heat loading in the form of pressure drop
and pump inefficiency can be used as a means to intentionally increase the temperature of
an incompressible fluid (water, H2O), through mathematical and computation studies.
Two mathematical equation models were performed providing initial predictions that a
pressure drop of 5000psi will produce about 14-degF of heating to the fluid. Taking
these predictions, 3D simulation models were created and were used to validate the
mathematical predictions to show that pressure drop of different pressure levels does
convert the potential energy in the fluid (in the form of the raised pressure) and converts
it to thermal energy (in the form of increase fluid temperatures). The simulation portion
on this thesis will show the setup and process for creating each simulation. The process
is first started with having models of both pressure relief valves and of an orifice to be
created to simulate both direct and hybrid heating of flowing water. Each model is then
meshed in to the computational fluid dynamics (CFD) preprocessor, ANSYS FLUENT.
After the CFD software setup was configured, each individual model is simulated in
FLUENT and the results are compared to determine the most optimized and efficient
model for heating water to a specified temperature level. By using two different relief
valve designs, it was determined that the pressure drop is the primary contributor to the
temperature. By comparing the three types of relief devices, the orifice was determined to
provide the most simplest and cost effective design, but also requires that the water
v
flowing through the restriction must be accurately conditioned so that a specific flow rate
and inlet pressure is maintained or the output temperature would be negatively affected
(lower than predicted temperature).
Finally 3D model of inlet tank concepts were
analyzed in ANSYS FLUENT to determine that a 7-8-degF increase to inlet water could
be provided which could reduce the amount of components required to heat the water to
an approximate range of 120-140-degF. Finally, this thesis will provide direction to what
further activities would be required to validate both the mathematical and simulated
results and provide conceptual design ideas.
_______________________, Committee Chair
Kenneth Sprott, Ph. D.
_______________________
Date
vi
DEDICATION
I dedicate this thesis to both my wife Jie, and my Daughter Patricia for giving me the
time, patience and support that I required to complete both my master’s work and this
thesis paper. Without your support, understanding, and a little distraction, I might not
have been able to accomplish it all. I also wish to give thanks to my Parents, Edward and
Margaret Little, for always having the belief that I could accomplish anything I put my
mind into, and to provide the push that I sometime needed to keep me going forward at
times in my life when I just wanted to stop and quit.
Thank you.
vii
ACKNOWLEDGEMENTS
I would like to acknowledge the following people who have given their assistance to this
thesis. Without their help and guidance, I would have had a hard time completing this
paper. First, I would like to thank Bruce Fong, my manager, for whom provided me the
flexible work time to be able to complete my master’s coursework and authorized the use
of resources required to complete this thesis. I would also like to thank Professor Tim
Marbach for being the second reader for this thesis and providing guidance of
thermodynamic topic related to this thesis. I would also like to thank Patrick Elrod for
his assistance in providing guidance for me when I was setting up the ANSYS FLUENT
CFD software used in this thesis. Finally, but not least, I would like to acknowledge
Professor Kenneth Sprott, for allowing me to work on this topic with him and to his
support, understanding, and patience while I progressed with completing this thesis work.
viii
TABLE OF CONTENTS
Page
Dedication .................................................................................................................. vii
Acknowledgements ................................................................................................... viii
List of Tables ............................................................................................................ xiv
List of Figures ............................................................................................................. xv
Chapter
1. INTRODUCTION ................................................................................................. 1
1.1
Heat Source – Open Flame ......................................................................... 2
1.2
Heat Source – Electrical Elements ............................................................. 4
1.3
Heat Source - Alternative............................................................................ 5
1.4
Heat Source - Mechanical ........................................................................... 9
2. HEAT LOAD AND PRESSURE DROP IN A HYDRAULIC SYSTEM ........... 11
3. MATHEMATICAL MODELS TO PREDICT HEAT LOAD PRESSURE DROP .
......................................................................................................................... 16
3.1
Pre-Simulation Equation 1 ........................................................................ 16
3.2
Pre-Simulation Equation 2 ........................................................................ 22
4. SIMULATION OF PRESSURE RELIEF DEVICE USING CFD SOFTWARE .....
......................................................................................................................... 27
4.1
Purpose ..................................................................................................... 27
4.2
Description of CFD Software .................................................................. 28
ix
4.3
Simulation of a Pressure Relief Valve ..................................................... 28
4.3.1
4.4
Simulation Setup ....................................................................................... 32
4.4.1
4.5
4.6
Simulation Applications ........................................................... 29
Model Geometry and Meshing of 3D Model ............................ 32
Governing Equations ................................................................................ 36
4.5.1
Continuity Equation ..................................................................37
4.5.2
Momentum Equation ................................................................38
4.5.3
Expressing Incompressible Flow ............................................. 40
4.5.4
Modeling the Turbulent Flow of a Relief Valve ........................41
CFD Settings used to Simulate Relief Valve .............................................47
4.6.1
4.6.2
4.6.3
Model – Solution Setup ............................................................ 47
4.6.1.1
FLUENT Launcher .................................................. 50
4.6.1.2
Solution Setup – General ........................................ 50
4.6.1.3
Solution Setup – Models .......................................... 52
4.6.1.4
Solution Setup – Materials ....................................... 53
Solution Cell and Boundary ....................................................... 54
4.6.2.1
Solution Setup – Cell Zone Conditions ................... 55
4.6.2.2
Solution Setup – Boundary Conditions.....................55
Numerical Setting in ANSYS FLUENT .................................... 59
4.6.3.1
Solution – Solution Methods ................................... 59
4.6.3.2
Solution – Solution Controls.....................................61
x
4.6.3.3
Solution – Solution Initialization and Simulation Run
.............................................................................................. 62
5. RELIEF VALVE SIMULATIONS RESULTS .................................................... 63
5.1
Simulation Constraints ...............................................................................63
5.2
(RRV) Simulation Results 1000psi Pressure Drop ................................... 64
5.3
(RRV) Simulation Results 5000psi Pressure Drop ................................... 81
5.4
Bosch Relief Valve Simulation ................................................................. 86
5.4.1
1000psi Pressure Drop Simulation Results ................................. 96
5.4.2
Realizable vs. Standard ..............................................................101
5.4.3
Other Pressure Drop Simulations.............................................. 103
5.4.3.1
4000psi Simulation Results ..................................... 104
5.4.3.2
3000psi Simulation Results ..................................... 105
5.4.3.3
2000psi Simulation Results ..................................... 106
5.4.3.4
Summary of Simulations Results for the Bosch Relief
Valve Model...................................................... 107
6. ALTERNATIVE PRESSURE RELIEF DEVICE - ORIFICE ........................... 108
6.1
Simulation Setup ..................................................................................... 111
6.2
3D Model Geometry and Meshing ......................................................... 111
6.3
User Defined Functions of CFD Simulation ............................................114
6.3.1
CFD Settings Used to Simulate Orifice ................................... 115
6.3.2
Governing Equations ............................................................... 115
xi
6.4
Orifice Simulation Results ...................................................................... 117
7. HEATER DESIGN CONCEPT AND HARDWARE SELECTION ................. 122
7.1
Hardware Design Criteria ....................................................................... 126
7.1.1
Reliability of Hardware.............................................................123
7.1.2
Cost Consideration ....................................................................124
7.1.3
Safety ....................................................................................... 125
7.2
Heater System Concept Design ...............................................................126
7.3
Inlet Tank Simulation ..............................................................................128
7.4
7.5
7.6
7.3.1
Inlet Tank – Relief Valve ..........................................................129
7.3.2
Inlet Tank – Orifice Device ......................................................135
7.3.3
Tank Concept Simulation Summary ........................................ 140
Pump Design ........................................................................................... 141
7.4.1
Permco Series 424 Gear Pump ................................................ 145
7.4.2
Salami Gear Pump ................................................................... 147
7.4.3
Flowing Water in a Gear Pump ............................................... 148
Relief Device Selection........................................................................... 148
7.5.1
Relief Valve ............................................................................. 149
7.5.2
Orifice ...................................................................................... 150
7.5.3
Relief Device Selection Summary ........................................... 151
Electric Pump Motor ............................................................................... 152
7.6.1
Electrical Consumption Calculations....................................... 153
xii
7.6.2
Alternative Motor Sizing and Design Concept .................. 157
8. PROPOSED FUTURE ACTIVITIES................................................................. 159
8.1
Proposed Proof of Concept Testing .................................................. 159
9. CONCLUSION ................................................................................................... 162
Appendix A
Reference Relief Valve (RRV) ..........................................................166
Appendix B
Bosch Relief Valve Simulation Results ............................................ 194
Appendix C
Orifice Simulation Results .................................................................220
Appendix D
Tank Concept Simulation Results ..................................................... 234
Appendix E
PG&E Electrical and Gas Rate – March 2014 .................................. 280
Appendix F
Water Property Tables .......................................................................281
Bibliography ............................................................................................................. 283
xiii
LIST OF TABLES
Tables
Page
1.
Temperature for Pressure vs. Flow Rate ........................................................... 19
2.
Temperature vs. Pressure Drop ......................................................................... 20
3.
Property Tables and Charts (English Units) ..................................................... 23
4.
Temperature vs. Pressure Drop ......................................................................... 75
5.
Pressure Drop Estimate for Flow Rate vs. Orifice Diameter .......................... 109
6.
Orifice Size for Pressure Drop vs. Flow Rate ................................................. 110
7.
Electric Motor Size for Hydraulic Pump Drive .............................................. 153
8.
Horse Power required with 95% Efficient Motor ........................................... 155
9.
Energy Cost for Electric Heaters (U.S. Department of Energy ...................... 157
xiv
LIST OF FIGURES
Figures
Page
1.
Diagram of a Heat pump water heater ................................................................ 6
2.
Diagram of an Active Solar water heater (www.energy.gov) ............................ 6
3.
Diagram of a Passive Solar water heater (www.energy.gov) ............................. 6
4.
Diagram of a tank-less water heater.................................................................... 8
5.
Diagram of a Tank-less water heater layout (www.tanklesswaterheaterguide.com)
............................................................................................................................. 9
6.
Pressure Drop vs. Temperature ......................................................................... 20
7.
Thermodynamic Model – Conservation of Energy Equation ......................... . 25
8.
Example Valve CAD 3D Model ....................................................................... 30
9.
Reference Relief Valve 3D Model (Side & Isometric Views) ....................... . 30
10.
RRV Mesh with Highlighted Cross-Section View ........................................... 31
11.
Boundary Wall Names (ANSYS) ..................................................................... 33
12.
ANSYS RRV Wall – INLET ............................................................................ 33
13.
ANSYS RRV Wall – OUTLET ........................................................................ 33
14.
ANSYS RRV Wall - Inlet Wall ........................................................................ 33
15.
ANSYS RRV Wall - Chamber Inlet Wall ........................................................ 33
16.
ANSYS RRV Wall - Chamber Outlet Wall ...................................................... 34
17.
ANSYS RRV Wall - Valve Outlet Wall ........................................................... 34
18.
ANSYS RRV Wall - Valve Inner Wall ............................................................ 34
xv
19.
ANSYS RRV Wall - Outlet Wall ................................................................... . 34
20.
Cell Shape Simulation in CAD ......................................................................... 35
21.
ANSYS FLUENT Workbench Display ............................................................ 48
22.
ANSYS FLUENT MESH Display.................................................................... 48
23.
MESH Sizing .................................................................................................... 49
24.
ANSYS Fluent Launcher Pop-up...................................................................... 50
25.
ANSYS Solution Setup – General Page ........................................................... 51
26.
ANSYS Solution Setup – Viscous Model ........................................................ 52
27.
ANSYS Solution Setup – Materials (Liquid Water)......................................... 53
28.
ANSYS Solution Setup – Materials (Steel) ...................................................... 54
29.
ANSYS Solution Setup – Cell Zone Conditions .............................................. 55
30.
ANSYS Solution Setup – Boundary Conditions (Thermal) ............................. 55
31.
ANSYS Solution Setup – Boundary Conditions (Momentum) ........................ 56
32.
ANSYS Solution Setup – Inlet ......................................................................... 56
33.
ANSYS Solution Setup – Inlet Conditions ....................................................... 57
34.
ANSYS Solution Setup – Outlet ....................................................................... 58
35.
ANSYS Solution Setup – Outlet Conditions .................................................... 58
36.
ANSYS Solution Setup – Solution Methods .................................................... 60
37.
ANSYS Solution Setup – Solution Controls .................................................... 61
38.
ANSYS Solution Setup – Initialization and Run .............................................. 62
39.
Reference Relief Valve Model (Pro-Engineer vs ANSYS) .............................. 66
xvi
40.
ANSYS Simulation Residual Plot .................................................................... 66
41.
ANSYS Simulation Contour Plot Control (Static and Total Pressure .............. 67
42.
ANSYS Simulation Contour Plot (Static Pressure RRV 1000psi) ................... 67
43.
ANSYS Simulation Contour Plot (Total Pressure RRV 1000psi) .................... 68
44.
ANSYS Simulation Velocity Vector Plot (Static Pressure RRV 1000psi)....... 69
45.
ANSYS Simulation Velocity Vector Plot (Total Pressure RRV 1000psi) ....... 69
46.
ANSYS Simulation Velocity Vector Plot ((Total Pressure – valve close-up).. 70
47.
ANSYS Simulation Contour Plot Control (Temperature) ................................ 70
48.
ANSYS Simulation Contour Plot (Total Temperature, RRV 1000psi) ............ 71
49.
ANSYS Simulation Velocity Vector Plot (Total Temperature, RRV 1000psi)….
........................................................................................................................... 72
50.
ANSYS Simulation DOT Plot (Total Pressure, RRV 1000psi) ........................ 72
51.
ANSYS Simulation Histogram (Total Pressure, RRV 1000psi) ...................... 73
52.
ANSYS Simulation DOT Plot (Total Temperature, RRV 1000psi) ................. 74
53.
ANSYS Simulation Histogram (Total Temperature, RRV 1000psi)................ 74
54.
ANSYS Simulation Contour Plot (Enthalpy, RRV 1000psi) ........................... 76
55.
ANSYS Simulation DOT Plot (Enthalpy, RRV 1000psi) ................................ 76
56.
ANSYS Simulation Histogram (Enthalpy, RRV 1000psi) ............................... 77
57.
ANSYS Simulation Contour Plot (Entropy, RRV 1000psi) ............................. 79
58.
ANSYS Simulation DOT Plot (Entropy, RRV 1000psi) .................................. 79
59.
ANSYS Simulation Histogram (Entropy, RRV 1000psi) ................................ 79
xvii
60.
ANSYS Simulation DOT Tri-Plot Comparison (Entropy vs. Total Energy and
Internal Energy, RRV 1000psi) ........................................................................ 80
61.
ANSYS Simulation Contour Control (RRV 5000psi) ...................................... 81
62.
ANSYS Simulation Contour Plot (Total Pressure, RRV 5000psi) ................... 81
63.
ANSYS Simulation Velocity Vector (Total Pressure, RRV 5000psi) .............. 82
64.
ANSYS Simulation Histogram (Total Pressure, RRV 5000psi) ...................... 82
65.
ANSYS Simulation Contour Plot (Total Temperature, RRV 5000psi) ............ 83
66.
ANSYS Simulation Histogram (Total Temperature, RRV 5000psi)................ 83
67.
ANSYS Simulation Contour Plot (Enthalpy, RRV 5000psi) ........................... 84
68.
ANSYS Simulation Dot Plot & Histogram (Enthalpy, RRV 5000psi) ............ 84
69.
ANSYS Simulation Contour Plot (Entropy, RRV 5000psi) ............................. 85
70.
ANSYS Simulation Dot Plot & Histogram (Entropy, RRV 5000psi) .............. 85
71.
ANSYS Simulation Dot Plot & Histogram (Entropy, RRV 5000psi) .............. 85
72.
ANSYS Simulation Dot Plots (Total Energy & Internal Energy, RRV 5000psi)
........................................................................................................................... 86
73.
ANSYS Simulation Histogram (Total Energy & Internal Energy, RRV, 5000psi)
........................................................................................................................... 86
74.
BOSCH Pressure Relief Valve Model# 9-530-232-130 ................................... 86
75.
Bosch 3D CAD Model – Pro-Engineer ............................................................ 88
76.
Bosch Relief Valve 3D ANSYS Model ............................................................ 89
77.
Bosch RV Model – Wall Names ....................................................................... 89
xviii
78.
Bosch 3D ANSYS – INLET Wall .................................................................... 90
79.
Bosch 3D ANSYS Model – OUTLET Wall ..................................................... 90
80.
Bosch 3D ANSYS Model – Inlet Outer Wall ................................................... 90
81.
Bosch 3D ANSYS Model – Outlet Outer Wall ................................................ 90
82.
Bosch 3D ANSYS Model – Upper Valve Wall ................................................ 90
83.
Bosch 3D ANSYS Model – Lower Valve Wall ............................................... 90
84.
Bosch 3D ANSYS Model – Inner Valve Wall ................................................. 90
85.
Bosch 3D ANSYS Model – Spring Wall .......................................................... 90
86.
Bosch 3D CAD Model – ANSYS MESH Cell ................................................. 91
87.
Bosch 3D CAD Model – ANSYS MESH Sizing ............................................. 92
88.
Bosch 3D CAD Model – ANSYS MESH Display ........................................... 92
89.
ANSYS Contour Plot (Absolute Pressure, Bosch RV, 5000psi) ...................... 93
90.
ANSYS Contour Plot (Total Pressure, Bosch RV, 5000psi) ............................ 94
91.
ANSYS Contour Plot (Density, Bosch RV, 5000psi)....................................... 94
92.
ANSYS Contour Plot (Total Temperature, Bosch RV, 5000psi) ..................... 95
93.
ANSYS Contour Plot (Enthalpy, Bosch RV, 5000psi)..................................... 95
94.
ANSYS Contour Plot (Entropy, Bosch RV, 5000psi) ...................................... 96
95.
ANSYS Simulation Setup – Inlet and Outlet (Bosch RV, 1000psi) ................. 97
96.
ANSYS Contour Plot (Total Pressure, Bosch RV, 1000psi) ............................ 98
97.
ANSYS Contour Plot Total Temperature, Bosch RV, 1000psi) ...................... 98
98.
ANSYS Dot Plot (Total Energy, Bosch RV, 1000psi) ..................................... 99
xix
99.
ANSYS Histogram (Total Temperature, Bosch RV, 1000psi) ......................... 99
100.
ANSYS Contour Plot (Total Enthalpy, Bosch RV, 1000psi) ......................... 100
101.
ANSYS Contour Plot (Total Entropy, Bosch RV, 1000psi) ........................... 100
102.
ANSYS Viscous Model Control Display (Realizable, Bosch RV, 1000psi) .. 101
103.
ANSYS Residual Plot Comparison (Standard vs. Realizable, Bosch RV, 1000psi)
......................................................................................................................... 101
104.
ANSYS Contour Plot – Total Pressure (Realizable vs. Standard, Bosch RV,
1000psi)........................................................................................................... 102
105.
ANSYS Contour Plot – Total Temperature (Realizable vs. Standard, Bosch RV,
1000psi)........................................................................................................... 102
106.
ANSYS Contour Plot – Enthalpy (Realizable vs. Standard, Bosch RV, 1000psi)
......................................................................................................................... 102
107.
ANSYS FLUENT Workbench – Simulation Plots (1000-5000psi) ............... 103
108.
ANSYS Contour Plot – Total Temperature (, Bosch RV, 4000psi) ............... 104
109.
ANSYS Contour Plot – Total Temperature (, Bosch RV, 3000psi) ............... 105
110.
ANSYS Contour Plot – Total Temperature (, Bosch RV, 2000psi) ............... 106
111.
Orifice Diagram .............................................................................................. 108
112.
Orifice 3D CAD Model – Pro-Engineer ......................................................... 112
113.
ANSYS Mesh – Orifice .................................................................................. 113
114.
ANSYS Orifice Mesh Size ............................................................................. 113
115.
Orifice Wall Boundary Names........................................................................ 114
xx
116.
ANSYS Orifice Simulation - Viscous Model and Reference Values ............. 114
117.
ANSYS Orifice Simulation – Inlet and Outlet Setup ..................................... 115
118.
ANSYS Contour Plots (Total Pressure & Velocity Magnitude, Orifice, 5000psi)
......................................................................................................................... 117
119.
ANSYS Orifice Simulation – 5000psi Total Temperature Plots .................... 118
120.
ANSYS Orifice Simulation – Inlet and Outlet Setup, 4000psi ....................... 119
121.
ANSYS Contour Plots (Pressure and Velocity Magnitude, Orifice, 4000ps)..…..
......................................................................................................................... 120
122.
ANSYS Contour Plots (Total Temperature, Orifice, 4000psi) ....................... 121
123.
ANSYS Dot Plot and Histogram (Total Temperature, Orifice, 4000psi) ....... 121
124.
Water Heater Design Concept Layout – Relief Valve .................................... 126
125.
ANSYS 3D Model – RV Tank Concept Model.............................................. 130
126.
ANSYS RV Tank Wall Names ....................................................................... 131
127.
ANSYS Boundary Condition Wall Controls – RV Tank Concept ................. 131
128.
ANSYS 3D Model Fluent Launcher – RV Tank Concept .............................. 132
129.
ANSYS Contour Plot (Total Pressure, RV Tank Concept Simulation).......... 132
130.
ANSYS Contour Plot (Static Temperature, RV Tank Concept Simulation) .. 133
131.
ANSYS Contour Plot (Total Temperature, RV Tank Concept Simulation) ... 134
132.
ANSYS 3D Model – Orifice Tank Concept Simulation................................. 135
133.
ANSYS 3D Model Orifice Tank Sim. (Outlet) .............................................. 136
134.
ANSYS 3D Model Orifice Tank Sim. (Inlet Wall) ........................................ 136
xxi
135.
ANSYS 3D Model Orifice Tank Sim. (Outlet Wall)...................................... 136
136.
ANSYS 3D Model Orifice Tank Simulation (Boundary Wall Names) .......... 136
137.
ANSYS 3D Model Orifice Tank Simulation (Mesh) ..................................... 137
138.
ANSYS Orifice Tank Sim. – Viscous Model Control .................................... 137
139.
ANSYS Contour Plot (Static Temperature, Orifice Tank Simulation)........... 139
140.
ANSYS Contour Plot (Total Temperature, Orifice Tank Simulation) ........... 140
141.
Gear Pump Operational Diagram (www.pumpzone.com) .............................. 143
142.
Gear Pump Fluid Slip (www.pumpzone.com) ................................................ 144
143.
PERMCO Gear Pump View (www.permco.com) .......................................... 145
144.
PERMCO Gear Pump Dimensional Data (www.permco.com) ...................... 146
145.
PERMCO Gear Pump Part Break Down (www.permco.com) ....................... 146
146.
SALAMI Gear Pump Views (www.salami.it) ................................................ 147
147.
SALAMI Gear Pump Detail (www.salami.it) ................................................ 147
148.
Pump Motor Pressure vs. Horse Power (85% EF) .......................................... 154
xxii