PIPE SYSTEM HYDRAULICS - Environmentally Conscious Materials Handling - page 235

CHAPTER 9
PIPE SYSTEM HYDRAULICS

Blake P. Tullis
Utah State University
Logan, Utah

1 INTRODUCTION 239

5.5 Air Release Valves 252

5.6 Combination Valves 253

1.1 Basic Fluid Mechanics
Equations

5.7 Pressure Relief Valves 253

240

1.2 Energy Losses 241

6 CENTRIFUGAL PUMP
SELECTION AND
PERFORMANCE

2 FLUID FRICTION 242

253

3 MINOR LOSSES 245

7 OTHER PIPELINE
OPERATION
CONSIDERATIONS

4 PIPE SELECTION 247

255

5 VALVES 248

7.1 External Loads 255

5.1 Control Valves 248

7.2 Maximum and Minimum Flow
Velocities

5.2 Check Valves 251

256

5.3 Air Valves 252

5.4 Air/Vacuum Valves 252

REFERENCES 256

1 INTRODUCTION

There are many factors that should be considered when designing a pipeline.
They include (but are not limited to): discharge capacity (present and future); pipe
diameter; maximum positive and negative steady state and transient pressures;
pipe material and pressure class; joint type, fluid type, and soil type; pumping
requirements; the need for storage in the system; live and static external loads;
the use of proper bedding material, installation techniques, and air valves to
reduce the risk of pipe collapse due to negative internal pressures; control valve
selection and operation; and proper filling, flushing, and draining protocols.
Negative pressures in the pipeline can cause external materials to leach into the
pipe through joints, potentially contaminating the fluid. As a worst-case scenario,
poor pipe design could lead to the collapse of the pipe. When the pipeline carries
a fluid that may be hazardous if introduced to the local environment, additional
precautions or design considerations are warranted. Such considerations should
include leak detection monitoring, isolation valves distributed along the length

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