Water Hammer: Practical Solutions

WATER HAMMER: PRACTICAL SOLUTIONS

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WATER HAMMER: PRACTICAL SOLUTIONS B. B. Sharp and D. B. Sharp Burnell Research Laboratory, Victoria, Australia

["lUTTER WORTH E I N E M A N N OXFORD AMSTERDAM BOSTON LONDON NEW YORK PARIS SAN DIEGO SAN FRANCISCO SINGAPORE SYDNEY TOKYO

Butterworth-Heinemann An imprint of Elsevier Science Linacre House, Jordan Hill, Oxford 0X2 8DP 200 Wheeler Road, Burlington, MA 01803 First published 1996 Transferred to digital printing 2003 Copyright © 1996, B. B. Sharp and D. B. Sharp. All rights reserved The right of B. B. Sharp and D. B. Sharp to be identified as the authors of this work has been asserted in accordance with the Copyright, Designs and Patents Act 1988 No part of this publication may be reproduced in any material form (including photocopying or storing in any medium by electronic means and whether or not transiently or incidentally to some other use of diis publication) without the written permission of the copyright holder except in accordance with the provisions of the Copyright, Designs and Patents Act 1988 or under the terms of a licence issued by the Copyright Licensing Agency Ltd, 90 Tottenham Court Road, London, England WIT 4LR Applications for the copyright holder's written permission to reproduce any part of this publication should be addressed to the publisher British Library Cataloguing in Publication Data A catalogue record for this book is available from the British Library ISBN 0 340 64597 0

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Contents

1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19. 20. 21. 22. 23. 24. 25. 26. 27.

V

Contents Nomenclature Introduction

vii ix

The Valve (Gate) The Pump The Booster Inertia An Optimum Pump Location The Non-return Valve (check valve) Non-return Valve as a Protection Method The Complex System The Separation Problem The Non-elastic Conduit The High Point Fire protection The Plumbing Problem Structural Interaction The Open Surge Tank The One-way Surge Tank The Pressure Reducing Valve The Resonance Problem Series Pumping Compounding of Pipes - System Alternatives The Impact of Waves - Coastal Defence Problem The Air Vessel A Hydroelectric Example Expansion Loops (Lyres) Dead End Cooling Water Systems Sewage Pumping

1 9 15 19 25 35 41 48 55 61 65 69 73 79 85 89 95 101 107 111 115 121 129 133 137 141 145

vi Contents 28. 29.

Blowdown from High-Temperature/Pressure Systems Classification Discussion

149 153

Appendix 1 Liquid and Material Properties Appendix 2 Data File for Complex Network Example References Index

155 159 165 171

Nomenclature

The diagrams and notations for the data follow the basic scheme of the computer analysis with the following conditions. The velocity is used as the basic flow variable and because the water-hammer wave propagation is a celerity the symbol C^ is used. Pipes ; numbered from the downstream end, have n(j) -f 1 internal points /, numbered from 1 to n{j) + 1 from the downstream node to the next upstream node. The wave propagation, shown by the arrows in thefigurebelow, is associated with a sign for CJg that is positive when passing in the direction of negative velocity and conversely negative when passing in the direction of positive velocity. NP«5 NPB«7

\ > \ ^ -CJg

^ / T ^CJg

^

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