Table of Contents

Acknowledgements xiii; Preface to the First Edition xv; Preface to the Second Edition xvii; Part 1; 1.1 Introduction 3; 1.1.1 Unacceptable Conditions 3; 1.1.2 Causes of Unsteady and Transient flows 4; 1.2 Unsteady Flows in Pipes and Tunnels 5; 1.2.1 Basic Ideas 5; 1.2.2 A Simple Example 6; 1.2.3 Pressure Wave Reflections and Pipeline Period 8; 1.2.4 A 'Rapid' Event 10; 1.2.5 Effects of Friction 10; 1.2.6 Max-Min Head Envelopes 10; 1.2.7 Column Separation and Vapour Cavity Formation 10; 1.2.8 Air and Gas Entrainment 12; 1.2.9 Fluid-Structure Interaction 13; 1.2.10 Water Hammer in Steam Pipelines 13; 1.2.11 Mass Oscillation and Rigid Column Behaviour 14; 1.2.12 Resonance and Auto-oscillation 15; 1.2.13 Key Points Developed in Sections 1.1 and 1.2 17; 1.3 Suppression of Fluid Transients 17; 1.3.1 Practical Methods of Surge Suppression 18; 1.3.2 Direct Action 18; 1.3.2.1 Stronger Pipes 18; 1.3.2.2 Rerouting 19; 1.3.2.3 Changing Valve Movements 19; 1.3.2.4 Avoiding Check Valve Slam 20; 1.3.2.5 Increasing the Inertia of Pumps and their Motors 22; 1.3.2.6 Minimizing Resonance Hazards 23; 1.3.3 Diversionary Tactics 24; 1.3.3.1 Air Vessels and Air Cushion Surge Chambers 25; 1.3.3.2 Accumulators 28; 1.3.3.3 Surge Shafts 29; 1.3.3.4 One-Way Surge Tanks (Feed Tanks) 30; 1.3.3.5 Vacuum-Breaking and Air Release Valves 31; 1.3.3.6 Pressure Relief Valves and Bursting Discs 33; 1.3.3.7 Bypass Lines 35; 1.3.3.8 Avoiding Water Hammer in Steam Pipelines 36; 1.3.4 Choice of Protection Strategy 36; 1.3.5 Summary of Part 1 38; Part 2; 2.1 Assessment and Management of Risk 43; 2.1.1 Introduction 43; 2.1.2 A Procedure for Fluid Transient Risk Assessments 47; 2.2 Demonstration Examples 49; 2.2.1 Rising Main Example 1 49; 2.2.2 Rising Main Example 2 61; 2.2.3 A Pumped Outfall 66; 2.2.4 A Gravity-Fed Main 69; 2.2.5 A Line to an Offshore Oil Terminal 72; 2.2.6 A Process System Supplied by a Ram Pump 76; 2.2.7 A High-Pressure Feed System 80; 2.2.8 Looped Networks 86; 2.2.9 An Ash Slurry Line 89; 2.2.10 A Sub-Sea Recharge System 92; 2.2.11 Cooling Water Systems 96; 2.2.12 A Phosphate Ester Pipeline 99; 2.2.13 Key Points Developed in Sections 2.1 and 2.2 101; 2.3 Computer Modelling of Transient Flows 102; 2.3.1 Introduction 102; 2.3.2 Brief Outline of Solution by the Method of Characteristics 103; 2.3.3 Idealizations and Assumptions 107; 2.3.4 Preparation for Computer-Aided Analyses 109; 2.3.4.1 System Data 110; 2.3.4.2 Fluid Data 110; 2.3.4.3 Pipes and Tunnels 110; 2.3.4.4 Junctions 110; 2.3.4.5 Pumps 111; 2.3.4.6 Valves 111; 2.3.4.7 Reservoirs, Sumps and Tanks 111; 2.3.4.8 Air Vessels, Accumulators and Surge Shafts 111; 2.3.4.9 Feed Tanks 112; 2.3.4.10 Bypass Lines 112; 2.3.4.11 Transient Event Data 112; 2.3.4.12 Aims and Objectives 113; 2.3.4.13 Expectations on Completion 113; 2.3.4.14 Idealizations and Assumptions 113; 2.3.4.15 Confirmation and Testing 114; 2.4 Accidents and Incidents 119; 2.4.1 The Case of the Lightweight Anchor Blocks 119; 2.4.2 The Dancing Feed Range 120; 2.4.3 Where has all the Water Gone? 121; 2.4.4 A Midnight Feast 122; 2.4.5 Green for Danger 123; 2.4.6 Minor Change - Major Problem 126; 2.4.7 A Positive Reflection 126; 2.4.8 Hanging Free 128; 2.4.9 The Devil is in the Detail 129; 2.4.10 Lessons to be Learned 130; 2.5 Transients: Current Status - Future Developments 131; 2.5.1 Summary of Fluid Transient Modelling Capability in 2003 131; 2.5.2 Knowledge Engineering and Fluid Transients 133; 2.5.3 Behaviour and Response of the Fluid 137; 2.5.4 Dynamic Behaviour of Components and Devices 138; 2.5.5 Fluid-Structure Interaction (FSI) 139; 2.5.6 Concluding Remarks 140; Part 3; 3.1 Some Basic Theory 143; 3.1.1 Change in Pressure across a Transient 143; 3.1.2 The Wave Speed Equation 144; 3.1.3 Equations for Calculating Wave Speeds 145; 3.1.3.1 Pipes of Circular Cross-Section 145; 3.1.3.2 Tunnels 151; 3.1.3.3 Plastic, uPVC and Glass-Reinforced Plastic Pipes 153; 3.1.3.4 Non-circular Ducts 153; 3.1.3.5 Liquids Other than Water 154; 3.1.3.6 Multiphase and Multicomponent Fluids 155; 3.1.3.7 Plastically Deforming Tubes 158; 3.1.3.8 Flexible Hoses 159; 3.1.3.9 Data for Wave Speed Estimates 160; 3.2 Rigid Column Approximations 162; 3.2.1 Equation of Motion 163; 3.2.2 Cavity Formation and Collapse in a Rising Main 164; 3.2.3 Air or Water Admission at a Low-Pressure Point 167; 3.3 Estimation of Air Vessel Capacities 168; 3.3.1 Rising Mains 168; 3.3.1.1 Unthrottled Air Vessels 169; 3.3.1.2 Throttled (Bypass) Air Vessels 185; 3.3.1.3 Worked Example and Outline Procedure 187; 3.3.2 Start-up of Deep-Well Pumps 190; 3.3.2.1 Outline Procedure 196; 3.3.2.2 Demonstration Example 197; 3.4 Pump Data 201; 3.4.1 Pump Performance Characteristics 201; 3.4.2 Moment of Inertia of Pumps and Motors 210; 3.4.2.1 Pump Inertias 210; 3.4.2.2 Motor Inertias 213; 3.5 Pressure Rises Following Valve Closure 214; 3.6 Air Relief and Vacuum-Breaking Valves 224; 3.6.1 Ventilation of Pipelines 225; 3.6.2 Air Valves for Surge Control 227; 3.6.3 Selection and Siting of Air Valves 230; 3.6.4 Air Valves in Fuel and Petrochemical Lines 233; 3.6.5 Air Valves for Sewage and Inustrial Effluents 234; 3.6.6 Air Valves for Deep-Well Installations 235; 3.6.7 The Sizing of Air Valves 235; 3.6.8 Care and Maintenance 238; 3.7 Pressure Relief and Safety Valves 238; 3.7.1 Sizing Considerations 241; 3.7.2 Bursting Discs 243; 3.8 Valve Characteristics 245; 3.8.1 Head Losses Through Valves 245; 3.8.2 Dynamic Performance of Check Valves 264; 3.9 Other Sources of Information 270; 3.9.1 Bibliography 270; 3.9.2 World Wide Web 271; References 274; Suggested Further Reading 279; Index 281

About the Author

Professor A. R. David Thorley BSc, MPhil, PhD, CEng, FIMechE, FICE, MemASME. Professor Emeritus of Fluid Engineering - City University, London, UK. Professor Thorley's engineering career began as an apprentice in the automobile industry, followed by a period as a graduate engineer in the electricity supply industry. Since joining the academic sector, he has maintained strong links with industry through extensive consultancy, research and development. This latter activity has been concerned with a variety of projects in the field of fluid engineering, predominantly concerned with the design of safe and reliable piping systems for the water, oil, nuclear and petrochemical industries, for which he has acquired an international reputation. The principal themes in this work have been the need to apply engineering common sense and judgement to challenge underlying assumptions in, and designs of, real piping systems, since most such systems are unique and yet a single mistake can have catastrophic consequences. Arising from his academic and R&D activities, Professor Thorley has published some 62 journal and conference papers, 50 industrial reports and briefing papers to project sponsors. He has also written, or been joint author of, books on fluid transients and the design of anchor blocks. In 1983 Professor Thorley founded the Thermo-Fluids Engineering Research Centre at City University and assembled around him a number of colleagues active in applying their skills to solving and understanding problems in thermo-fluids engineering, which would directly benefit UK industry. Much of their work related to the energy sector and attracted funding from industry at home and abroad, as well as from Research Councils. From 1993 to 1999 Professor Thorley was Head of the Department of Mechanical Engineering and Aeronautics, then Dean of the School of Engineering from 1999 to 2001, embracing activities in aeronautical, civil, electrical and electronic, and mechanical engineering. Among his professional activities, Professor Thorley has contributed to the organization of several international conferences on unsteady and transient flows in pipeline systems and been Chairman of three of them. He has been an active member of ESDU working parties for Design Items, and Scientific Advisor and representative of the EEC Commissioners for a transient flow project at the Delft Hydraulics Laboratory in the Netherlands. He has travelled and lectured overseas professionally on numerous occasions, visiting India, Indonesia, North and South Africa, and North and South America, often by invitation and sometimes at the instigation of the British Council. He is registered with the World Bank as a consultant and has been an expert witness in the High Court in London. Professor Thorley is married with three grown-up children. They share many activities as a family, but specific interests include sailing (the Caribbean, Europe, the Mediterranean, and the Far East), and travel. He is a member of the Little Ship Club and Cruising Association, and a Governor of the RNLI. Since retiring from full-time employment he has extended his sailing including a trans-Atlantic passage to the Caribbean where he is currently cruising among the islands.