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Fluid flow measurement
Fluid Flow Measurement A Practical Guide to Accurate Flow Measurement CH00ppi-x 10/24/01 4:45 PM Page i CH00ppi-x 10/24/01 4:45 PM Page ii Fluid Flow Measurement A Practical Guide to Accurate Flow Measurement Second Edition E.L. Upp Paul J. LaNasa Boston Oxford Auckland Johannesburg Melbourne New Delhi CH00ppi-x 10/24/01 4:45 PM Page iii Gulf Professional Publishing is an imprint of Butterworth–Heinemann. Copyright © 2002 by Butterworth–Heinemann A member of the Reed Elsevier group All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, without the prior written permission of the publisher. Recognizing the importance of preserving what has been written, Butterworth–Heinemann prints its books on acid-free paper whenever possible. Butterworth–Heinemann supports the efforts of American Forests and the Global ReLeaf program in its campaign for the betterment of trees, forests, and our envi- ronment. Library of Congress Cataloging-in-Publication Data Fluid flow measurement: a practical guide to accurate flow measurement / E.L. Upp, Paul J. LaNasa. p.cm. Includes bibliographical references and index. ISBN 0-88415-758-X (alk. Paper) 1. Fluid dynamic measurements. 2. Flow meters. I. LaNasa, Paul J., 1941- II. Title. TA357.5.M43 U66 2001 681’ .28—dc21 2001030550 British Library Cataloguing-in-Publication Data A catalogue record for this book is available from the British Library. The publisher offers special discounts on bulk orders of this book. For information, please contact: Manager of Special Sales Butterworth–Heinemann 225 Wildwood Avenue Woburn, MA 01801–2041 Tel: 781-904-2500 Fax: 781-904-2620 For information on all Gulf Professional Publishing publications available, contact our World Wide Web home page at: http://www.gulfpp.com 10 9 8 7 6 5 4 3 2 1 Printed in the United States of America CH00ppi-x 10/24/01 4:45 PM Page iv Contents Dedication . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . viii Preface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ix CHAPTER 1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1 Chapter Overview, 1. Requisites of Flow Measurement, 2. Background of Flow Measurement, 3. History of Flow Measurement, 4. Definition of Terms, 6. CHAPTER 2 Basic Flow Measurement Laws . . . . . . . . . . . . . . . . . . . . . . . . . . . . .24 Reynolds Number, 26. Gas Laws, 27. Expansion of Liquids, 31. Fundamental Flow Equation, 32. References, 34. CHAPTER 3 Types of Fluid Flow Measurement . . . . . . . . . . . . . . . . . . . . . . . . . . .35 Custody Transfer, 36. Non-Custody Transfer Measurement, 46. References, 47. CHAPTER 4 Basic Reference Standards . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .48 American Gas Association (AGA), 49. American Petroleum Institute (API), 52. American Society of Mechanical Engineers (ASME), 63. American Society of Testing Materials (ASTM), 64. Gas Processors Association (GPA), 65. Instrument Society of America (ISA), 67. CHAPTER 5 From Theory to Practice . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .72 “Ideal” Installations, 73. Non-Ideal Installations, 74. Fluid Characteristics Data, 74. References, 90. CHAPTER 6 Fluids . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .91 Fluids—Liquids and Gases, 91. Fluid Characteristics, 97. Liquids, 104. References, 108. v CH00ppi-x 10/24/01 4:45 PM Page v CHAPTER 7 Flow . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .109 Required Characteristics, 109, Measurement Units, 111, Installation Requirements, 112, Flow Pattern, 113, References, 115. CHAPTER 8 Operations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .116 Operational Considerations, 116. Operational Influences on Gas Measurement, 117. Uncertainty, 123. Other Fluid Flow Considerations, 132. CHAPTER 9 Maintenance Meter Equipment . . . . . . . . . . . . . . . . . . . . . . . . . . . .136 Gas Measurement Maintenance, 138. Effects of Liquids and Solids on Orifice Measurement, 146. Effects on Other Meters, 149. General Maintenance of Liquid Meters, 150. Specific Liquid Maintenance Problems, 152. CHAPTER 10 Measurement and Meters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .154 Meter Characteristics, 154. Types of Meters, 156. CHAPTER 11 Differential (Head) Meters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .162 Orifice Meter, 164. Meter Design Changed, 165. Orifice Meter Description, 169. Sizing, 170. Equations, 171. Maintenance, 174. Flow Nozzles, 175. Venturi Meters, 178. Venturi Installation, 179. Other Head Meters, 180. CHAPTER 12 Linear and Special Meters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .183 Non-Intrusive Meters, 184. Intrusive Linear Meters, 192. Other and Special-Purpose Meters, 206. References, 211. CHAPTER 13 Readouts and Related Devices . . . . . . . . . . . . . . . . . . . . . . . . . . . .213 Electronics, 213. Related Devices, 215. Crude Oil Sampling, 221. Natural Gas Sampling, 221. Calorimetry, 225. References, 225. vi Fluid Flow Measurement CH00ppi-x 10/24/01 4:45 PM Page vi CHAPTER 14 Proving Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .226 Liquid Provers, 227. Gas Provers, 232. Critical Flow Provers, 233. Central Test Facility, 234. References, 234. CHAPTER 15 “Loss and Unaccounted for” Fluids . . . . . . . . . . . . . . . . . . . . . . . .236 Introduction, 235. Liquid, 236. Gas, 239. CHAPTER 16 Auditing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .244 Introduction, 244. Gas Meters, 245. Liquid Meters, 245. Analysis Equipment, 246. Audit Principles, 246. Objective, 247. Procedures, 247. Evidence, 248. Definitive Testing, 248. Sources of Information, 250. Contract Review, 250. Field Measurement Equipment Review, 251. Data Review and Comparison, 251. Auditing Gas Measurement Systems, 252. Chart Review, 253. Auditing Liquid Measurement, 253. Finalizing the Audit, 254. Conclusion, 254. Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .255 Contents vii CH00ppi-x 10/24/01 4:45 PM Page vii Dedication We dedicate this book to our families, particularly our wives, Carol LaNasa and Ann Upp, who assumed most of the responsibilities in raising our families while we worked and traveled in pursuit of our careers. And we express deepest appreciation to the companies—Tennessee Gas Pipeline, The Boeing Company, Daniel Industries (now the Daniel Division of Emerson Process Management), NuTech Industries, and CPL & Associates—whose assignments provided the opportunity for most of our flow-measurement experience. Also, we offer special appreciation to the Daniel Division of Emerson Process Management, whose financial support allowed this book to be pub- lished. For over 70 years, Daniel technical personnel have helped customers solve flow-measurement problems. During this time it has become appar- ent to us that good flow measurement is not a simple commodity to be se- lected solely by comparing product specifications. Rather, successful flow measurement results from application of good products with a full under- standing of the equally important topics discussed in this book. We subtitled the book “A practical guide to accurate flow measurement” and are quite confident that practical know-how comes only from a thor- ough understanding of fluid flow basics coupled with extensive experience. We have tried to share our experience and that of our peers through the ex- amples and illustrations in the book. If our readers can make any contribu- tion to reducing flow measurement uncertainties by application of the book’s information, we will feel more than amply rewarded for the time and effort invested in writing it. viii Fluid Flow Measurement CH00ppi-x 10/24/01 4:45 PM Page viii Preface As noted in the preceding Dedication, the tendency to make flow meas- urement a highly theoretical and technical subject overlooks a basic tenet: Practical application of meters, metering principles, and metering instru- mentation and related equipment is the real key to quality measurement. And that includes the regular maintenance by trained and experienced per- sonnel with quality equipment required to keep flow-measurement systems operating so as to achieve their full measurement potential. We cannot begin to name the many friends who make up our background of experience. They include the pioneers in flow measurement, flow-meas- urement design engineers, operating personnel—ranging from top-manage- ment to the newest testers—academic and research based engineers and scientists, worldwide practitioners, theorists, and those just getting started in the business. Deepest appreciation goes to our friends at Daniel, especially Gene Perkins, division president. Daniel’s financial support and encouragement to write without bias for or against any specific manufacturer made this book possible. A special thanks to Patsye Roesler of Daniel, who typed from our notes and multiple revisions (which we often had trouble deciphering ourselves), and to Jim Anthony, who edited and made our Louisiana cajun readable to the English-speaking public. Our personal experience has been that explaining creates the most com- plete comprehension. Standing in front of a “class” as a “student” asks for an explanation of a point just covered, quickly and clearly separates what you have learned by rote from that which you truly understand. One finds out very rapidly what he really knows. Hopefully you will find that which you need to know and understand. Why another book on flow measurement? Several factors motivated us. We have mentioned our emphasis on the practical side of the subject. Another reason is the large number of early retirements by experienced measurement personnel. And a third consideration is the tendency to make our various measurement standards “technically defensible”—but confusing. We felt simply that a practical guide could be a useful project. In the material covering standards, the brief overviews are coupled with our hope that interested readers will consult the documents and organiza- tions listed for additional information. In the same vein, detailed theoretical Preface ix CH00ppi-x 10/24/01 4:45 PM Page ix discussions are left to such excellent sources as the latest edition of the Flow Measurement Engineering Handbook by R.W. Miller. Because of the extent of such detailed information, we present only outlines along with ref- erence information for the reader’s use. We hope that enough practical information will be found in this book to help a reader analyze a flow problem to the extent that direction to the other detailed references will become clear. We have tried to “demystify” flow measurement by breaking the subject into simple sections and discussing them in everyday terms. Each technology has its own terminology and jar- gon; that’s why you will find many definitions and explanations of terms in the book. In short, flow measurement is based on science, but successful applica- tion depends largely on the art of the practitioner. Too frequently we blindly follow the successful artist simply because “that’s the way we’ve always done it.” Industry experience the world over shows, however, that under- standing why something is done can almost always generate better flow measurement. REFERENCE 1. Miller, Richard W. 1996. Flow Measurement Engineering Handbook, Third Edition. New York: McGraw-Hill. x Fluid Flow Measurement CH00ppi-x 10/24/01 4:45 PM Page x [...]... meters are available for measuring flow Proper selection involves a full understanding of all pertinent characteristics relative to a specific measurement job BACKGROUND OF FLOW MEASUREMENT The subjects below form the background for fluid flow measurement that should be understood before embarking on the task of choosing a flow measurement system Fluid, ” flow and measurement are defined in generally... continuity Measurement: 1 the act or process of measuring; 2 a figure, extent, or amount obtained by measuring CH01pp001-023 4 10/24/01 4:46 PM Page 4 Fluid Flow Measurement Combining these into one definition for fluid flow measurement yields: Fluid flow measurement: the measurement of smoothly moving particles that fill and conform to the piping in an uninterrupted stream to determine the amount flowing... achieved until the fluid is properly prepared for measurement On the other hand, the cost of preparing the fluid and/or the flow may sometimes outweigh the value of the flow measurement, and less accuracy should be accepted HISTORY OF FLOW MEASUREMENT Flow measurement has evolved over the years in response to demands to measure new products, measure old products under new conditions of flow, and for tightened... Ideal: Flow that follows theoretical assumptions Flow, Layered: Flow that has sufficient liquid present so the gas flows at a velocity above that for liquid flow at the bottom of a line This flow is not accurately measured with current flow meters Flow, Non-Fluctuating: Flow that has gradual variation in rate over long periods of time Flow, Non-Swirling: Flow with velocity components moving in straight... across the pipe Flow, Pulsating: The variation in flow rate that has a frequency higher than the meter-station frequency response Flow, Slug: Flow with sufficient liquid present so that the liquid collects in low spots and then “kicks over” as a solid slug of liquid This flow is not accurately measured with current flow meters 11 CH01pp001-023 12 10/24/01 4:46 PM Page 12 Fluid Flow Measurement Flow, Totalized:... defines the condition of the flow into the meter Flow Proportional Composite Sampling: The process of collecting gas over a period of time at a rate that is proportional to the pipeline flow rate Flow Rate: The volume or mass of flow through a meter per unit time Flow Regime: The characteristic flow behavior of a flow process Flow Temperature: The average temperature of a flowing stream taken at a specified... stream taken at a specified location in a metering system Fluid Flow Measurement: The measurement of smoothly moving particles that fill and conform to the piping in an uninterrupted stream to determine the amount flowing Fluid Dynamics: Mechanics of the flow forces and their relation to the fluid motion and equilibrium Fluids, Dehydrated: Fluids that normally have been separated into gas and liquid... are exposed to the flowing fluid CH02pp023-034 10/24/01 4:46 PM Page 24 CHAPTER 2 Basic Flow Measurement Laws All of the following laws should be recognized and met before flow measurement is attempted Certain physical laws explain what happens in the “real” world Some of these laws explain what happens when fluid flows in a pipeline, and these in turn explain what happens in a flowing stream as it... Measurement Chapter 14.3, Part 2 In flow measurement applications in which the fluid velocity is well below sonic, it is common practice to inset a temperaturesensing device in the middle of the flowing stream to obtain the flowing temperature For practical applications, the sensed temperature is assumed to be the static temperature of the flowing fluid The use of flowing temperature in this part of... Temperature Stratification: At low flow rates, proper mixing does not take place; layers of flow have different temperatures, densities, and speed of sound Proper mixing must be achieved to measure the fluid temperature Throughput Tests: The passage at the flowing fluid through the operating meter compared to volume standard at the operating flow rate Transition Flow: Flow, with a variable velocity profile, . Fluid Flow Measurement A Practical Guide to Accurate Flow Measurement CH00ppi-x 10/24/01 4:45 PM Page i CH00ppi-x 10/24/01 4:45 PM Page ii Fluid Flow Measurement A. Requisites of Flow Measurement, 2. Background of Flow Measurement, 3. History of Flow Measurement, 4. Definition of Terms, 6. CHAPTER 2 Basic Flow Measurement