ASME MFC-6–2013

[Revision and Redesignation of ASME MFC-6M–1998 (R2005)]

Measurement of Fluid Flow in Pipes Using Vortex Flowmeters

AN A MERICAN NA TIONAL S T AND ARD

Copyright c 2013 by the American Society of Mechanical Engineers.

No reproduction may be made of this material without written consent of ASME.

MFC-6–2013

[Revision and Redesignation of ASME MFC-6M–1998 (R2005)]

MFC-6–2013

[Revision and Redesignation of ASME MFC-6M–1998 (R2005)]

Measurement of Fluid Flow in Pipes Using Vortex Flowmeters

AN AMERICAN NATIONAL STANDARD

Two Park Avenue • New York, NY • 10016 USA

Date of Issuance: July 31, 2013

This Standard will be revised when the Society approves the issuance of a new edition.

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CONTENTS

Foreword iv

Committee Roster v

Correspondence With the MFC Committee vi

Nonmandatory Appendices

1. Period Jitter and Its Effect on Calibration 11

2. Bibliography 12

iii

FOREWORD

This Standard has been prepared by Subcommittee 6, Vortex Shedding Flowmeters, of the ASME Standards Committee for Measurement of Fluid Flow in Closed Conduits (MFC). It is one of a series of standards covering a variety of devices that measure the flow of fluids in closed conduits. The vortex shedding principle has become an accepted basis for fluid flow measurement. Flowmeters based on this principle are available for measuring the flow of fluids ranging from cryogenic liquids to steam and high-pressure gases. Vortex shedding flowmeters are also referred to as vortex meters. Their designs are proprietary, and therefore, their design details and associated uncer- tainty bands cannot be covered in this Standard. However, these devices have in common the shedding of alternating pairs of vortices from some obstruction in the meter.

This Standard contains the relevant terminology, test procedures, list of specifications, application notes, and equa- tions with which to determine the expected performance characteristics.

This revision was approved by the American National Standards Institute on February 19, 2013.

iv

ASME MFC COMMITTEE

Measurement of Fluid Flow in Closed Conduits

(The following is the roster of the Committee at the time of approval of this Standard.)

STANDARDS COMMITTEE OFFICERS

R. J. DeBoom, Chair

Z. D. Husain, Vice Chair

D. C. Wyatt, Vice Chair

C. J. Gomez, Secretary

STANDARDS COMMITTEE PERSONNEL

C. J. Blechinger, Honorary Member, Consultant G. E. Mattingly, The Catholic University of America

R. M. Bough, Rolls-Royce Corp. R. W. Miller, Honorary Member, R. W. Miller & Associates, Inc.

M. S. Carter, Flow Systems, Inc. A. Quraishi, American Gas Association

R. J. DeBoom, Consultant R. N. Steven, Colorado Engineering Experiment Station, Inc.

D. Faber, Contributing Member, Badger Meter, Inc. D. W. Spitzer, Contributing Member, Spitzer and Boyes, LLC

C. J. Gomez, The American Society of Mechanical Engineers J. H. Vignos, Honorary Member, Consultant

F. D. Goodson, Emerson Process Management — Daniel D. E. Wiklund, Emerson Process Management — Rosemount

Z. D. Husain, Chevron Corp. J. D. Wright, Contributing Member, National Institute of

C. G. Langford, Honorary Member, Consultant Standards and Technology

W. M. Mattar, Invensys/Foxboro Co. D. C. Wyatt, Wyatt Engineering

SUBCOMMITTEE 6 — VORTEX SHEDDING FLOWMETERS

W. M. Mattar, Chair, Invensys/Foxboro Co. M. Moeller, Krohne Messtechnik GmbH

G. Coutinho, Krohne Marshall Private Ltd. J. G. Olin, Sierra Instruments Inc.

R. J. DeBoom, Consultant P. I. Moore, Chevron Corp.

J. Foster, Emerson Process Management — Rosemount B. K. Rao, Consultant

J. J. Freiberg, Racine Federated Inc. D. W. Spitzer, Spitzer and Boyes, LLC

H. E. Hall, Dow Chemical Canada ULC J. A. Storer, Vortek Instruments LLC

Z. D. Husain, Chevron Corp. J. H. Vignos, Consultant

M. J. Keilty, Endress Hauser Flowtec AG D. E. Wiklund, Emerson Process Management — Rosemount

G. E. Mattingly, The Catholic University of America

v

CORRESPONDENCE WITH THE MFC COMMITTEE

General. ASME Standards are developed and maintained with the intent to represent the consensus of concerned interests. As such, users of this Standard may interact with the Committee by requesting interpretations, proposing revisions, and attending Committee meetings. Correspondence should be addressed to:

Secretary, MFC Standards Committee

The American Society of Mechanical Engineers Two Park Avenue

New York, NY 10016-5990

https://go.asme.org/Inquiry

Proposing Revisions. Revisions are made periodically to the Standard to incorporate changes that appear neces- sary or desirable, as demonstrated by the experience gained from the application of the Standard. Approved revi- sions will be published periodically.

The Committee welcomes proposals for revisions to this Standard. Such proposals should be as specific as possible, citing the paragraph number(s), the proposed wording, and a detailed description of the reasons for the proposal, including any pertinent documentation.

Proposing a Case. Cases may be issued for the purpose of providing alternative rules when justified, to permit early implementation of an approved revision when the need is urgent, or to provide rules not covered by existing provisions. Cases are effective immediately upon ASME approval and shall be posted on the ASME Committee Web page.

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Subject: Cite the applicable paragraph number(s) and the topic of the inquiry.

Edition: Cite the applicable edition of the Standard for which the interpretation is being requested.

Question: Phrase the question as a request for an interpretation of a specific requirement suitable for general understanding and use, not as a request for an approval of a proprietary design or situation.

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Attending Committee Meetings. The MFC Standards Committee regularly holds meetings, which are open to the public. Persons wishing to attend any meeting should contact the Secretary of the MFC Standards Committee.

vi

ASME MFC-6–2013

MeasureMent of fluid flow in PiPes using Vortex flowMeters

1. sCoPe

   This Standard

   1. describes the use of vortex flowmeters, including their physical components, principle of operation, instal- lation, performance, influence factors, and calibration in a closed conduit running full for the measurement of volu- metric flow rate and volume flow total of single-phase liquids or gases, including vapors such as steam

   2. describes the use of vortex flowmeters in combi- nation with one or more other process measurements for the inferential measurement of mass flow rate, mass flow total, base volumetric flow rate, base volume total, and heat flow metering

   3. is limited to full-bore flowmeters and does not include the special case of insertion-type flowmeters

      
      

2. referenCes and related doCuMents

   Unless otherwise indicated, the latest issue of a refer- enced standard shall apply.

   ASME MFC-1M, Glossary of Terms Used in the Measurement of Fluid Flow in Pipes

   Publisher: The American Society of Mechanical Engineers (ASME), Two Park Avenue, New York, NY 10016- 5990; Order Department: 22 Law Drive, P.O. Box 2900, Fairfield, NJ 07007-2900 (www.asme.org)

   
   

   IEC 60529, Degrees of Protection Provided by Enclosures (IP Code)

   Publisher: International Electrotechnical Commission (IEC), 3, rue de Varembé, Case Postale 131, CH-1211 Genève 20, Switzerland/Suisse (www.iec.ch)

   
   

3. terMinologY and sYMBols

3.1 definitions from asMe MfC-1M used in this standard

For the purposes of this Standard, the following defi- nitions are particularly useful in describing the charac- teristics of vortex shedding flowmeters. ASME MFC-1M provides a more extensive collection of definitions and symbols pertaining to the measurement of fluid flow in closed conduits.

cavitation: the implosion of vapor bubbles formed after flashing when the local pressure rises above the vapor pressure of the liquid.

flashing: the formation of vapor bubbles in a liquid when the local pressure falls to or below the vapor pressure of the liquid, often due to local lowering of pressure because of an increase in the liquid velocity.

K factor: in pulses per unit volume, the ratio of the meter output in number of pulses to the corresponding total volume of fluid passing through the meter during a measured period. Variations in the K factor may be pre- sented as a function of either the meter bore Reynolds number or the flow rate of a specific fluid at a specific set of thermodynamic conditions (see Fig. 9.2-1).

lowest local pressure: the lowest pressure found in the meter. This is the pressure of concern regarding flashing and cavitation. Some of the pressure is recovered down- stream of the meter.

meter bore Reynolds number: a dimensionless ratio of iner- tial to viscous forces that is used as a correlating param- eter that combines the effects of viscosity, density, and pipeline velocity. It is defined as

Re  DU

D m

meter factor: the reciprocal of the mean K factor.

pressure loss: the difference between the upstream pres- sure and the pressure downstream of the meter after recovery.

random error: a component of the error of measurement that, in the course of a number of measurements of the same measurand, varies in an unpredictable way.

NOTE: It is not possible to correct for random error.

random uncertainty: a component of uncertainty associ- ated with a random error. Its effect on mean values can be reduced by taking many measurements.

rangeability: flowmeter rangeability is the ratio of the maxi- mum to minimum flow rates or Reynolds number in the range over which the meter meets a specified uncertainty.

response time: for a step change in flow rate, response time is the time needed for the indicated flow rate to

1