_RP_688-2012_2021.pdf

Pulsation and Vibration Control in Positive Displacement Machinery Systems for Petroleum,Petrochemical,and Natural Gas Industry ServicesAPI RECOMMENDED PRACTICE 688 FIRST EDITION,APRIL 2012REAFFIRMED,JULY 2021Special NotesAPI 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 APIs 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 APIs 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 InstituteForewordThis 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 infring