1、Specification for ValvesAPI SPECIFICATION 6DTWENTY-FIFTH EDITION,NOVEMBER 2021API MONOGRAM PROGRAM EFFECTIVE DATE:NOVEMBER 2022ERRATA 1,DECEMBER 2021Special NotesAPI publications necessarily address problems of a general nature.With respect to particular circumstances,local,state,and federal laws an
2、d 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 maymandate compliance.Neither API nor any of APIs employees,subcontractors,consultants,committees,or other
3、 assignees make anywarranty or representation,either express or implied,with respect to the accuracy,completeness,or usefulness of theinformation contained herein,or assume any liability or responsibility for any use,or the results of such use,of anyinformation or process disclosed in this publicati
4、on.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 theaccuracy and
5、reliability of the data contained in them;however,the Institute makes no representation,warranty,orguarantee in connection with this publication and hereby expressly disclaims any liability or responsibility for loss ordamage resulting from its use or for the violation of any authorities having juri
6、sdiction with which this publication mayconflict.API publications are published to facilitate the broad availability of proven,sound engineering and operatingpractices.These publications are not intended to obviate the need for applying sound engineering judgmentregarding when and where these public
7、ations should be utilized.The formulation and publication of API publicationsis 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 standardis solely responsible for complying
8、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.Users of this specification should not rely exclusively on the information contained in this document.Sound business,scientific,engin
9、eering,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 permi
10、ssion from the publisher.Contact the Publisher,API Publishing Services,200 Massachusetts Avenue,NW,Suite 1100,Washington,DC 20001.Copyright 2021 American Petroleum InstituteForewordNothing contained in any API publication is to be construed as granting any right,by implication or otherwise,for thema
11、nufacture,sale,or use of any method,apparatus,or product covered by letters patent.Neither should anythingcontained in the publication be construed as insuring anyone against liability for infringement of letters patent.The verbal forms used to express the provisions in this document are as follows.
12、Shall:As used in a standard,“shall”denotes a minimum requirement in order to conform to the standard.Should:As used in a standard,“should”denotes a recommendation or that which is advised but not required in orderto conform to the standard.May:As used in a standard,“may”denotes a course of action pe
13、rmissible within the limits of a standard.Can:As used in a standard,“can”denotes a statement of possibility or capability.This document was produced under API standardization procedures that ensure appropriate notification andparticipation in the developmental process and is designated as an API sta
14、ndard.Questions concerning theinterpretation of the content of this publication or comments and questions concerning the procedures under whichthis publication was developed should be directed in writing to the Director of Standards,American PetroleumInstitute,200 Massachusetts Avenue,Suite 1100,Was
15、hington,DC 20001.Requests for permission to reproduce ortranslate 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-timeextension of up to two years may be
16、 added to this review cycle.Status of the publication can be ascertained from theAPI Standards Department,telephone(202)682-8000.A catalog of API publications and materials is publishedannually by API,200 Massachusetts Avenue,Suite 1100,Washington,DC 20001.Suggested revisions are invited and should be submitted to the Standards Department,API,200 MassachusettsAvenue,Suite 1100,Washington,DC 20001,standardsapi.org.iiiContentsPage1Scope.12Normative References .13Terms,Definitions,Acronyms,Abbrevia
