_API_Std_611_1997.pdf

General-Purpose Steam Turbines for Petroleum,Chemical,and Gas Industry Services API STANDARD 611 FOURTH EDITION,JUNE 1997COPYRIGHT 2000 American Petroleum InstituteInformation Handling Services,2000COPYRIGHT 2000 American Petroleum InstituteInformation Handling Services,2000COPYRIGHT 2000 American Petroleum InstituteInformation Handling Services,2000COPYRIGHT 2000 American Petroleum InstituteInformation Handling Services,2000 General-Purpose Steam Turbinesfor Petroleum,Chemical,and GasIndustry Services Manufacturing,Distribution and Marketing Department API STANDARD 611FOURTH EDITION,JUNE 1997COPYRIGHT 2000 American Petroleum InstituteInformation Handling Services,2000COPYRIGHT 2000 American Petroleum InstituteInformation Handling Services,2000 SPECIAL NOTES API publications necessarily address problems of a general nature.With respect to partic-ular circumstances,local,state,and federal laws and regulations should be reviewed.API is not undertaking to meet the duties of employers,manufacturers,or suppliers towarn and properly train and equip their employees,and others exposed,concerning healthand safety risks and precautions,nor undertaking their obligations under local,state,orfederal laws.Information concerning safety and health risks and proper precautions with respect to par-ticular materials and conditions should be obtained from the employer,the manufacturer orsupplier of that material,or the material safety data sheet.Nothing contained in any API publication is to be construed as granting any right,byimplication or otherwise,for the manufacture,sale,or use of any method,apparatus,or prod-uct covered by letters patent.Neither should anything contained in the publication be con-strued as insuring anyone against liability for infringement of letters patent.Generally,API standards are reviewed and revised,reaffirmed,or withdrawn at least everyfive years.Sometimes a one-time extension of up to two years will be added to this reviewcycle.This publication will no longer be in effect five years after its publication date as anoperative API standard or,where an extension has been granted,upon republication.Statusof the publication can be ascertained from the API Authoring Department telephone(202)682-8000.A catalog of API publications and materials is published annually and updatedquarterly by API,1220 L Street,N.W.,Washington,D.C.20005.This document was produced under API standardization procedures that ensure appropri-ate notification and participation in the developmental process and is designated as an APIstandard.Questions concerning the interpretation of the content of this standard or com-ments and questions concerning the procedures under which this standard was developedshould be directed in writing to the director of the Authoring Department(shown on the titlepage of this document),American Petroleum Institute,1220 L Street,N.W.,Washington,D.C.20005.Requests for permission to reproduce or translate all or any part of the materialpublished herein should also be addressed to the director.API standards are published to facilitate the broad availability of proven,sound engineer-ing and operating practices.These standards are not intended to obviate the need for apply-ing sound engineering judgment regarding when and where these standards should beutilized.The formulation and publication of API standards is not intended in any way toinhibit anyone from using any other practices.Any manufacturer marking equipment or materials in conformance with the markingrequirements of an API standard is solely responsible for complying with all the applicablerequirements of that standard.API does not represent,warrant,or guarantee that such prod-ucts do in fact conform to the applicable API standard.All rights reserved.No part of this work may be reproduced,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,1220 L Street,N.W.,Washington,D.C.20005.Copyright 1997 American Petroleum InstituteCOPYRIGHT 2000 American Petroleum InstituteInformation Handling Services,2000COPYRIGHT 2000 American Petroleum InstituteInformation Handling Services,2000 iii FOREWORD This standard is based on the accumulated knowledge and experience of manufacturersand users of steam turbines.The objective of this publication is to provide a purchase speci-fication to facilitate the manufacture and procurement of general-purpose steam turbines foruse in petroleum refinery service.The primary purpose of API standards for mechanical equipment is to establish minimummechanical requirements.This limitation in scope is one of charter as opposed to interest andconcern.Energy conservation is of concern and has become increasingly important in allaspects of equipment design,application,and operation.Thus,innovative energy-conservingapproaches should be aggressively pursued by the manufacturer an