M00044957
New product
API RP 688 (R2021) Pulsation and Vibration Control in Positive Displacement Machinery Systems for Petroleum, Petrochemical, and Natural Gas Industry Services, First Edition
standard by American Petroleum Institute, 04/01/2012
In stock
Warning: Last items in stock!
Availability date: 01/06/2022
API RECOMMENDED PRACTICE 688 FIRST EDITION, APRIL 2012
REAFFIRMED, JULY 2021
API publications necessarily address problems of a general nature. With respect to particular circumstances, local, state, and federal laws and regulations should be reviewed. The use of API publications is voluntary. In some cases, third parties or authorities having jurisdiction may choose to incorporate API standards by reference and may mandate compliance.
Neither API nor any of API's employees, subcontractors, consultants, committees, or other assignees make any warranty or representation, either express or implied, with respect to the accuracy, completeness, or usefulness of the information contained herein, or assume any liability or responsibility for any use, or the results of such use, of any information or process disclosed in this publication. Neither API nor any of API's employees, subcontractors, consultants, or other assignees represent that use of this publication would not infringe upon privately owned rights.
API publications may be used by anyone desiring to do so. Every effort has been made by the Institute to assure the accuracy and reliability of the data contained in them; however, the Institute makes no representation, warranty, or guarantee in connection with this publication and hereby expressly disclaims any liability or responsibility for loss or damage resulting from its use or for the violation of any authorities having jurisdiction with which this publication may conflict.
API publications are published to facilitate the broad availability of proven, sound engineering and operating practices. These publications are not intended to obviate the need for applying sound engineering judgment regarding when and where these publications should be utilized. The formulation and publication of API publications is not intended in any way to inhibit anyone from using any other practices.
Any manufacturer marking equipment or materials in conformance with the marking requirements of an API standard is solely responsible for complying with all the applicable requirements of that standard. API does not represent, warrant, or guarantee that such products do in fact conform to the applicable API standard.
Classified areas may vary depending on the location, conditions, equipment, and substances involved in any given situation. Users of this Recommended Practice should consult with the appropriate authorities having jurisdiction.
Users of this Recommended Practice should not rely exclusively on the information contained in this document. Sound business, scientific, engineering, and safety judgment should be used in employing the information contained herein.
All rights reserved. No part of this work may be reproduced, translated, stored in a retrieval system, or transmitted by any means, electronic, mechanical, photocopying, recording, or otherwise, without prior written permission from the publisher. Contact the Publisher, API Publishing Services, 200 Massachusetts Avenue, NW, Suite 1100, Washington, DC 20001.
Copyright © 2012 American Petroleum Institute
This document is intended to describe, discuss and clarify the design of pulsation and vibration control for positive displacement machinery systems used for services in the petroleum, petrochemical and natural gas industries. The original focus of this document was to provide insight on the many changes to the pulsation and vibration material in the Clause 7.9 of the 5th Edition of API 618 for reciprocating compressors only. Due to industry interest, the scope of this document has been expanded to include other types of positive displacement equipment (such as pumps and screw compressors). However, due to publication schedules, these other types of positive displacement equipment will be addressed in future editions.
This document is not intended to be an all-inclusive source of information for this complex subject. Rather, it is offered as an introduction to the major aspects of pulsation and vibration control for positive displacement machinery addressed during a typical system design. A significant amount of the material has been extracted from documents previously published by the contributors. The different design philosophies of the various contributors are consolidated in this document to help users understand the choices available and make informed decisions about what is appropriate for their application. While the theory is generally applicable to all types of positive displacement machinery, the text in this edition will frequently refer specifically to reciprocating compressors.
Nothing contained in any API publication is to be construed as granting any right, by implication or otherwise, for the manufacture, sale, or use of any method, apparatus, or product covered by letters patent. Neither should anything contained in the publication be construed as insuring anyone against liability for infringement of letters patent.
Shall: As used in a standard, “shall” denotes a minimum requirement in order to conform to the specification.
Should: As used in a standard, “should” denotes a recommendation or that which is advised but not required in order to conform to the specification.
This document was produced under API standardization procedures that ensure appropriate notification and participation in the developmental process and is designated as an API standard. Questions concerning the interpretation of the content of this publication or comments and questions concerning the procedures under which this publication was developed should be directed in writing to the Director of Standards, American Petroleum Institute, 200 Massachusetts Avenue, NW, Suite 1100, Washington, DC 20001. Requests for permission to reproduce or translate all or any part of the material published herein should also be addressed to the director.
Generally, API standards are reviewed and revised, reaffirmed, or withdrawn at least every five years. A one-time extension of up to two years may be added to this review cycle. Status of the publication can be ascertained from the API Standards Department, telephone (202) 682-8000. A catalog of API publications and materials is published annually by API, 200 Massachusetts Avenue, NW, Suite 1100, Washington, DC 20001.
Suggested revisions are invited and should be submitted to the Standards Department, API, 200 Massachusetts Avenue, NW, Suite 1100, Washington, DC 20001, standards@api.org.
iii
v
Pulsation and Vibration Control in Positive Displacement Machinery Systems for Petroleum, Petrochemical, and Natural Gas Industry Services
The purpose of this document is to provide guidance on the application of pulsation and vibration control requirements found in the API purchasing specifications for positive displacement machinery. The fundamentals of pulsation and piping system analysis are presented in this Part.
The text begins with an overview of the fundamentals of pulsation and mechanical theory in Section 3. The intent of Section 3 is to introduce terminology and define the elements of the analysis process. Section 4 begins with a discussion of the acoustic and mechanical modeling techniques associated with the different design philosophies, which emphasize either pulsation or mechanical control, and concludes with a discussion on the appropriate selection of a Design Approach and Philosophy. Section 5 discusses the effects of pulsation on the accuracy of various types of flow measurement devices. Section 6 summarizes the requirements for documenting study results. Section 7 offers guidance on the performance of field testing to validate the results of the design process and to troubleshoot pulsation or vibration problems. Finally, methodologies for conducting a dynamic analysis of the compressor or pump valve performance are described in Section 8. The material in this Part is generally applicable to all types of positive displacement machinery.
Part 2 deals specifically with reciprocating compressors and provides commentary regarding each paragraph of Clause 7.9 of API 618, 5th Edition. It is the intent of the API Subcommittee on Mechanical Equipment that similar material be provided on reciprocating pumps and screw compressors in future editions.
For the purposes of this document, the following definitions apply.
Process whereby the one-dimensional acoustic characteristics of fluids, and the reciprocating compressor dynamic flow influence on these characteristics, are modeled taking into account the fluid properties, the compressor model and the connected vessels and piping, and other equipment. The model is based upon the governing mathematical equations (motion, continuity, etc.). The simulation should allow for determination of pressure/flow modulations at any point in the piping model resulting from any generalized compressor excitation. (Refer also to 2.2, 2.4, 2.9, 2.13, 2.16, and 2.18.)
Portion of the acoustic simulation in which the pressure pulsation amplitudes due to imposed compressor(s) operation for the anticipated loading, speed range and state conditions are predicted. (Refer to 2.1.)
Measure of acoustic or vibration sensitivity to excitation when the frequency of the excitation source is coincident with or near an acoustic or mechanical natural frequency. A high amplification factor (AF > 10) indicates that vibration during operation near a natural frequency could be excessive. A low amplification factor (e.g. AF < 5) indicates that the system is not as sensitive to excitation when operating in the vicinity of the associated acoustic or mechanical
1