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Transcript of Reciprocating Compressors
Gulf Professional Publishingan imprint of Butterworth-Hememann
H E I N Z P. B L O C K AND JOHN J. HOEFNER
This book is dedicated to the mechanics, technicians, engineers, and managers whose quest for excellence leads them to be resourceful... and who recognize that resourcefulness includes reaching for the written word.
Copyright 1996 by Butterworth-Heinemann. All rights reserved. Printed in the United States of America. This book, or parts thereof, may not be reproduced in any form without permission of the publisher. Originally published by Gulf Publishing Company, Houston, TX. For information, please contact: Manager of Special Sales Buttewoith-Heinemann 225 Wildwood Avenue Woburn, MA 01801-2041 Tel: 781-904-2500 Fax:781-904-2620 For information on all Butterworth-Heinemann publications available, contact our World Wide Web home page at: http://www.bh.com
10 9 8 7 6 5 4 3 Library of Congress Cataloging-in-Publication Data Bloch, Heinz P., 1933Reciprocating compressors : operation and maintenance / Heinz P. Bloch, John J. Hoefner. p. cm.
Includes bibliographical references and index.ISBN 0-88415-525-0 (alk. paper) 1. Compressors. 2. CompressorsMaintenance and repair. I. Hoefner, John J. II. Title. TJ990.B547 1996 621.5'1dc20 96-3059 CIP Printed in the United States of America Printed on Acid-Free Paper ()IV
ContentsACKNOWLEDGMENTS, vii PREFACE, ix1 RECIPROCATING COMPRESSORS ANDTHEIR APPLICATIONSIntroduction. What Is a Compressor? How Compressors Work. Methods of Compression. Types of Compressors. Compressor Definitions. Pressure. Pressure Definitions Associated with Compressors. Theory of Reciprocating Compressors. Characteristics of Reciprocating Compressors. Compressor Type Selection, Reciprocating Compressor Cylinder Arrangements.
2 DESIGN AND MATERIALS FOR RECIPROCATING COMPRESSOR COMPONENTS 44Materials of Construction. Non-Lubricated or Oil-Free Cylinder Construction. Piston Rod Column or Frame Loading. Disturbing or Shaking Forces. Foundations for Reciprocating Compressors. Compressor Piping and Pulsation. Design Overview of Labyrinth Piston Compressors.
3 OPERATION AND MAINTENANCE OF RECIPROCATING COMPRESSORSLubrication of Reciprocating Compressors. Operational Problems and Maintenance of Compressor Valves. Compressor Piston Rod Packing. Compressor Control Systems. Compressor Cylinder Cooling. Non-Lubricated Compressor Maintenance. LabyrinthPiston Compressors.
4 OVERHAUL AND REPAIR OF RECIPROCATING COMPRESSORSRule of Thumb for General Running Clearances. Compressor Alignment. Web Deflection Measurements. Compressor Cylinder
Alignment. Foundation Problems and Repairs. Compressor Bearing Maintenance and Replacement. Cylinder Repair and Maintenance. Compressor Piston Maintenance. Rebuilding Compressor Pistons. Installing Pistons Bn Piston Rods. Setting Piston End Clearances. Inspection and Reconditioning Piston Rods. Manufacture of Compressor Piston Rods. Other Compressor Component Repairs. Compressor Part Replication.
5 TROUBLESHOOTING COMPRESSOR PROBLEMSIntroduction. Compressor Problems. Typical Compressor Problems. Troubleshooting Lubrication Systems. Significance of Intercooler Pressures. Interstage Pressures. Belt Drives. Motor Controls. Diagnostic Tests. Evaluating Reciprocating Compressor Condition Using Ultrasound and Vibration Patterns. Compressor Service Technician Reports. Basic Air Compressor System Evaluation.
6 PREVENTIVE MAINTENANCE FOR RECIPROCATING: Introduction. Compressor Maintenance. Emergency Repairs Should Be Minimized. Effectiveness of Preventive Maintenance. Compressor Preventive Maintenance Program. Spare Parts. Vendor Selection. Personnel Training. Maintenance Contractors. Predictive Maintenance. Integrated Condition Monitoring Systems.
7 SAFETY IN OPERATION AND MAINTENANCEBasic Safety Rules. Lock-Out/Tag-Out Program. Safe Maintenance Procedures Restated. Valve Installation. Fires and Explosions. Summary. Air Piping.
APPENDIX: RECIPROCATING COMPRESSOR CALCULATIONS, 389 INDEX, 408
AcknowledgmentsThe authors are indebted to a number of compressor manufacturers for granting permission to use copyrighted material for this text. First among these is Dresser-Rand's Olean, New York, facilitysuccessor company to John Hoefner's original employer, The Worthington Compressor Company of Buffalo, New York. We also acknowledge Ingersoll-Dresser (Painted Post, New York), Sulzer-Burckhardt (Wmterthur, Switzerland) for allowing us to use material on labyrinth piston machines, and Nuovo Pignone (Florence, Italy) whose input on ethylene hyper-compressors originated from one of their technical publications, Quaderni Pignone. The reader should note that this text was originally compiled for a three-day intense course presented by the authors for the Center for Professional Advancement, East Brunswick, New Jersey. Please contact the center for information on in-plant and public presentations. Disclaimer The information contained in this text has been compiled from various sources. It is believed to be reliable and to represent the best current opinion or practice relative to this topic. Neither the authors nor the equipment manufacturers or the publisher offers any warranty, guarantee, or representations as to its absolute correctness or sufficiency. The authors, equipment manufacturers, and publisher assume no responsibility in connection therewith; nor should it be assumed that all acceptable safety and regulatory measures are contained herein, or that other or additional information may or may not be required under particular or exceptional conditions or circumstances.
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PrefaceOne doesn't have to do too much research to establish how old reciprocating compressor technology really is. If steam turbines ushered in die Industrial Revolution over 200 years ago, reciprocating compressors couldn't have been far behind. On a visit to an Iowa-based equipment manufacturer in 1989, I was amazed to see how a 1908-vintage reciprocating compressor satisfied their around-the-clock plant air requirements dependably and efficiently. Eighty years with nothing but routine, albeit conscientious, "tender loving care" maintenance! What an endorsement of the skill of the original designers, machine builders, and generations of maintenance craftsmen. It's only fair to say that the old turn-of-the-century compressor was designed with greater margins of safety, or strength, or capacity to survive abuse than today's higher rotating speed and higher linear piston velocity reciprocating machines. Many of today's compressors are likely to have been designed with the emphasis on reduced weight, less floor space and, let's face it, least cost. The concepts of maintainability, surveillability, and true life cycle cost are too new to be taught in modem universities and engineering colleges. The reward system for project managers, process design contractors, and project engineers is largely based on capital cost savings and rapid schedules. Regrettably, even the commitment to maintenance excellence of many of today's managers and mechanic/technicians is not always as sound, or as rigorous and consistent, as it perhaps was a few decades ago. Today, everyone speaks of reliability, but many of these well-meaning folks seem to be "forgetful hearers" instead of "doers." There are precious few instances where the maintenance or reliability technician is given either the time or the training to determine the true root causes of equipment failures. Scores of workers are instructed to find the defective part, replace it with a new one, and get the machine back in service. But
the part failed for a reason, and if we don't find the reason for its failure, we are certain to set ourselves up for a repeat event. Whenever we rush a maintenance task, we are likely to omit taking the types of measurements that are critically important to the achievement of ran length extensions and increased reliability and safety. What is needed is more attention to detail; the notion that equipment reliability can be upheld by fixing only those components that are visibly defective may not always be correct. There may be compelling reasons to call for a restoration of all fits, clearances, and dimensions to as-designed values. This takes time and planning. It requires access to authoritative data and a fundamental shift away from business-as-usual, quick-fix, or big-picture attitudes. Time and again we have seen reciprocating compressor owners/users engage in the search for the high technology solution. When a succession of broken valves is encountered, the hunt concentrates on better valve materials instead of the elimination of moisture condensation and flowinduced liquid slugging. When piston rods wear unevenly, some users pursue superior metallic coatings, but close their ears to the possibility of tolerance stackup being the real culprit. This progressive move towards out-of-roundness or not-so-perfect perpendicularity of mating parts could well be the root cause of equipment distress and would have to be rectified before it makes economic sense to install components with advanced configurations or metallurgical compositions/And we might add that it wouldn't hurt if someone took the time to carefully read and implement the original equipment manufacturer's maintenance manual. With the downsizing and re-engineering of organizations in the United States and most other industrialized countries came the attrition of experienced personnel. Less time is spent on rigorous training, and outside contractors are asked to step into the gap. Where do they get their training? How diligently wi