_MFC_12M_Edtn_2006.pdf

AN AMERICAN NATIO NAL STANDARDMeasurement ofFluid Flow in Closed Conduits Using Multiport Averaging Pitot Primary ElementsASME MFC-12M2006Copyrighted material licensed to Stanford University by Thomson Scientific(),downloaded on Oct-05-2010 by Stanford University User.No further reproduction or distribution is permitted.Uncontrolled when printed.ASME MFC-12M2006Measurement ofFluid Flow in ClosedConduits UsingMultiport AveragingPitot PrimaryElementsAN AMERICAN NATIONAL STANDARDThree Park Avenue New York,NY 10016Copyrighted material licensed to Stanford University by Thomson Scientific(),downloaded on Oct-05-2010 by Stanford University User.No further reproduction or distribution is permitted.Uncontrolled when printed.Date of Issuance:October 9,2006This Standard will be revised when the society approves the issuance of a new edition.There willbe no addenda issued to this edition.ASME issues written replies to inquiries concerning interpretations of technical aspects of thisStandard.Interpretations are published on the ASME website under the Committee Pages athttp:/www.asme.org/codes/as they are issued.ASME is the registered trademark of The American Society of Mechanical Engineers.This code or standard was developed under procedures accredited as meeting the criteria for American NationalStandards.The Standards Committee that approved the code or standard was balanced to assure that individuals fromcompetent and concerned interests have had an opportunity to participate.The proposed code or standard was madeavailable forpublic review andcomment thatprovides an opportunityfor additional publicinput from industry,academia,regulatory agencies,and the public-at-large.ASME does not“approve,”“rate,”or“endorse”any item,construction,proprietary device,or activity.ASME does not take any position with respect to the validity of any patent rights asserted in connection with anyitems mentioned in this document,and does not undertake to insure anyone utilizing a standard against liability forinfringement of any applicable letters patent,nor assume any such liability.Users of a code or standard are expresslyadvised that determination of the validity of any such patent rights,and the risk of infringement of such rights,isentirely their own responsibility.Participation by federal agency representative(s)or person(s)affiliated with industry is not to be interpreted asgovernment or industry endorsement of this code or standard.ASME accepts responsibility for only those interpretations of this document issued in accordance with the establishedASME procedures and policies,which precludes the issuance of interpretations by individuals.No part of this document may be reproduced in any form,in an electronic retrieval system or otherwise,without the prior written permission of the publisher.The American Society of Mechanical EngineersThree Park Avenue,New York,NY 10016-5990Copyright 2006 byTHE AMERICAN SOCIETY OF MECHANICAL ENGINEERSAll rights reservedPrinted in U.S.A.Copyrighted material licensed to Stanford University by Thomson Scientific(),downloaded on Oct-05-2010 by Stanford University User.No further reproduction or distribution is permitted.Uncontrolled when printed.CONTENTSForeword.ivCommittee Roster.vCorrespondence With the MFC Committee.vi1Scope.12Terms and Definitions.13References.24Operating Principles.35Flow Equations.56Unit Construction Considerations.57Installation Effects.68Operation.79Flow Coefficient.710 Flow Rate Measurement Uncertainty.7Figures1APT Showing Total and Reference Pressure Sensed on the Strut.42APT Showing Total Pressure Sensed on the Strut and Reference Pressure Sensedat the Pipe Wall.4Tables1Symbols.2Nonmandatory AppendicesATypical Cross Sections of Multiport Averaging Pitot Primary Elements.9BMultiport Averaging Pitot Primary Element Flow Theory.10iiiCopyrighted material licensed to Stanford University by Thomson Scientific(),downloaded on Oct-05-2010 by Stanford University User.No further reproduction or distribution is permitted.Uncontrolled when printed.FOREWORDMultiport averaging pitot primary elements cover a family of head-class devices that makeuse of the Bernoulli principal to measure the flow of liquids and gases.This Standard tries toclarify differences between the construction and operation of these devices and other head-classdevices,such as orifice meters,Venturi meters,and nozzles.Due to differences in the design of multiport averaging pitot primary elements,this Standardcannot address detailed performance characteristics in specific applications.It does cover issuesthat are common to such devices.Suggestions for improvements to this Standard are encouraged and should be sent to:Secretary,ASME MFC Committee,the American Society of Mechanical Engineers,Three Park Avenue,NewYork,NY 10016-5990.ASME MFC-12M2006 was approved by the American National Standard Institute onMarch 21,2006.ivCopyrighted material licensed to Stanford University by Thomson Scientific(),downloaded on Oct-05-2010 b