1、 AMERICAN NATIONAL STANDARD ANSI/ISA-75.11.01-2013 Inherent Flow Characteristic and Rangeability of Control Valves Approved 30 January 2013 ANSI/ISA75.11.012013 Inherent Flow Characteristic and Rangeability of Control Valves ISBN: 978-0-876640-01-2 Copyright 2013 by the International Society of Auto
2、mation. All rights reserved. Not for resale. Printed in the United States of America. No part of this publication may be reproduced, stored in a retrieval system, or transmitted in any form or by any means (electronic mechanical, photocopying, recording, or otherwise), without the prior written perm
3、ission of the Publisher. ISA 67 Alexander Drive P.O. Box 12277 Research Triangle Park, North Carolina 27709 - 3- ANSI/ISA75.11.012013 Preface This preface, as well as all footnotes and annexes, is included for information p urposes and is not part of ANSI/ISA-75.11.01-2013. This document has been pr
4、epared as part of the service of the International Society of Automation toward a goal of uniformity in the field of instrumentation. To be of real value, this document should not be static but should be subject to periodic review. Toward this end, the Society welcomes all comments and criticisms an
5、d asks that they be addressed to the Secretary, Standards and Practices Board; ISA; 67 Alexander Drive; P. O. Box 12277; Research Triangle Park, NC 27709; Telephone (919) 549-8411; Fax (919) 549-8288; E-mail: standardsisa.org. The ISA Standards and Practices Department is aware of the growing need f
6、or attention to the metric system of units in general, and the International System of Units (SI) in particular, in the preparation of instrumentation standards. The Department is further aware of the benefits to USA users of ISA standards of incorporating suitable references to the SI (and the metr
7、ic system) in their business and professional dealings with other countries. Toward this end, this Department will endeavor to introduce SI-acceptable metric units in all new and revised standards, recommended practices, and technical reports to the greatest extent possible. Standard for Use of the
8、International System of Units (SI): The Modern Metric System, published by the American Society for Testing the minimum is 0.021. Figure 1 Example of globe valve specimen compared to manufacturer-specified flow characteristic ANSI/ISA75.11.012013 - 12- INHERENT RANGEABILITY OF TEST = = 91 SPECIMEN (
9、per Subclause 2.1.3): The maximum relative flow coefficient meeting the requirements of Clause 4 is 0.91; the minimum is 0.01. *Tolerance band for = 0.01 is 10 0.2 = 25% of = 0.01. Figure 2 Example of butterfly valve specimen compared to manufacturer-specified flow characteristic Developing and prom
10、ulgating sound consensus standards, recommended practices, and technical reports is one of ISAs primary goals. To achieve this goal the Standards and Practices Department relies on the technical expertise and efforts of volunteer committee members, chairmen and reviewers. ISA is an American National
11、 Standards Institute (ANSI) accredited organization. ISA administers United States Technical Advisory Groups (USTAGs) and provides secretariat support for International Electrotechnical Commission (IEC) and International Organization for Standardization (ISO) committees that develop process measurement and control standards. To obtain additional information on the Societys standards program, please write: ISA Attn: Standards Department 67 Alexander Drive P.O. Box 12277 Research Triangle Park, NC 27709 ISBN: 978-0-876640-01-2
