ANSI ASME MFC-22-2007 Measurement of Liquid by Turbine Flowmeters《用涡轮流量计测量液体》.pdf

1、Measurementof Liquid by Turbine FlowmetersAN AMERICAN NATIONAL STANDARDASME MFC-222007Intentionally left blank ASME MFC-222007Measurementof Liquid byTurbineFlowmetersAN AMERICAN NATIONAL STANDARDThree Park Avenue New York, NY 10016Date of Issuance: April 14, 2008This Standard will be revised when th

2、e 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 thisdocument. Periodically certain actions of the ASME MFC Committee may be published as Cases.Cases and interp

3、retations are published on the ASME Web site under the Committee Pages athttp:/cstools.asme.org 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 Nat

4、ionalStandards. 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 for public review and comment that provides an opportunity

5、for additional public input 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 connect

6、ion 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 suc

7、h 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

8、 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 pri

9、or written permission of the publisher.The American Society of Mechanical EngineersThree Park Avenue, New York, NY 10016-5990Copyright 2008 byTHE AMERICAN SOCIETY OF MECHANICAL ENGINEERSAll rights reservedPrinted in U.S.A.CONTENTSForeword ivCommittee Roster . vCorrespondence With the MFC Committee .

10、 vi1 Scope . 12 References . 13 Definitions and Symbols 14 Principle of Measurement. 25 Selection of Meter and Accessory Equipment for Flow Rate Determination . 26 Installation 47 Meter Performance . 78 Operation and Maintenance . 89 Measurement Uncertainty. 10Figures1 Typical Meter Performance Curv

11、e . 22 Schematic of Liquid Turbine Meter (Upstream-Downstream Stator) . 33 Schematic of Liquid Turbine Meter (Cantilever Stator) . 44 Typical Turbine Meter System . 45 Typical Installation of an Upstream Flow Conditioner 56 Typical Performance Curve of Turbine Meter Showing Effect of Back Pressure 6

12、Tables1 Symbols 32 Results of the Uncertainty Example 12iiiFOREWORDTurbine flowmeters cover a family of devices with varying designs that depend on rotatingblades for the measurement of fluid velocity. This Standard is for liquid turbine meters and isnot intended for gas turbine meters. The primary

13、purpose of the liquid turbine flowmeter is tomeasure flowing volume. The flowing volume can be recalculated as volume at a specific set ofconditions or as mass flow with the proper addition of additional measurements that can includetemperature, pressure, and analytical devices.The liquid flow turbi

14、ne meters can be used for process monitoring, control, and custody transferapplications.Suggestions for improvement of this Standard are welcome. They should be sent to: TheAmerican Society of Mechanical Engineers, Attn: Secretary, MFC Standards Committee, ThreePark Avenue, New York, NY 10016-5990.F

15、ollowing approval by the Standards Committee and the ASME Board, this Standard wasapproved as an American National Standard on June 8, 2007, with the designationASME MFC-222007.ivASME MFC COMMITTEEMeasurement of Fluid Flow in Closed Conduits(The following is the roster of the Committee at the time o

16、f approval of this Standard.)STANDARDS COMMITTEE OFFICERSR. J. DeBoom, ChairZ. D. Husain, Vice ChairC. J. Gomez, SecretarySTANDARDS COMMITTEE PERSONNELC. J. Blechinger, Member Emeritus, ConsultantR. M. Bough, Rolls-Royce Motor CarsG. P. Corpron, ConsultantR. J. DeBoom, ConsultantR. H. Fritz, Corresp

17、onding Member, Lonestar Measurement however, they shouldnot contain proprietary names or information.Requests that are not in this format will be rewritten in this format by the Committee priorto being answered, which may inadvertently change the intent of the original request.ASME procedures provid

18、e for reconsideration of any interpretation when or if additionalinformation that might affect an interpretation is available. Further, persons aggrieved by aninterpretation may appeal to the cognizant ASME Committee or Subcommittee. ASME does not“approve,” “certify,” “rate,” or “endorse” any item,

19、construction, proprietary device, or activity.Attending Committee Meetings. The MFC Committee regularly holds meetings, which are opento the public. Persons wishing to attend any meeting should contact the Secretary of theMFC Standards Committee.viASME MFC-222007MEASUREMENT OF LIQUID BY TURBINE FLOW

20、METERS1 SCOPEThis Standard describes the criteria for the applicationof a turbine flowmeter with a rotating blade for themeasurement of liquid flows through closed conduitrunning full.The standard discusses the following:(a) considerations regarding the liquids to bemeasured(b) turbine flowmeter sys

21、tem(c) installation requirements(d) design specifications(e) the maintenance, operation, and performance(f) measurement uncertaintiesThis Standard does not address the details of theinstallation of accessory equipment used to measurepressure, temperature, and/or density for the accuratedetermination

22、 of mass or base volumes, or those accesso-ries used to automatically compute mass or basevolumes.2 REFERENCESThe following is a list of publications referenced in thisStandard. Unless otherwise specified, the latest editionshall apply.ANSI/NCSL Z540.2-1997 (R2002), U.S. Guide toExpression of Uncert

23、ainty in MeasurementPublisher: NCSL International, 2995 Wilderness Place,Suite 107, Boulder, CO 80301-5404ASME MFC-1M, Glossary of Terms Used in theMeasurement of Fluid Flows in PipesPublisher: The American Society of MechanicalEngineers (ASME), Three Park Avenue, New York,NY 10016-5990; Order Depar

24、tment: 22 Law Drive,P.O. Box 2300, Fairfield, NJ 07007-2300ISO Guide to the expression of uncertainty inmeasurementPublisher: International Organization forStandardization (ISO), 1 ch. de la Voie-Creuse, Casepostale 56, CH-1211, Geneve 20, Switzerland/SuisseNIST Technical Note 1297 (TN 1297), Guidel

25、ines forEvaluating and Expressing the Uncertainty of NISTMeasurement ResultsPublisher: United States Department of Commerce,Technology Administration, National Institute ofStandards and Technology (NIST), 100 Bureau Drive,1Gaithersburg, MD 20899; http:/physics.nist.gov/Pubs/guidelines/TN1297/tn1297s

26、.pdf3 DEFINITIONS AND SYMBOLSMuch of the vocabulary and many of the symbolsused in this Standard are defined in ASME MFC-1M.Others that are unique in the field under consideration,or with special technical meanings are given in para. 3.1.Where a term has been adequately defined in the maintext, refe

27、rence is made to the appropriate paragraph.3.1 Definitionsbase flow rate: flow rate converted from flowing condi-tions to base conditions of pressure and temperature,generally expressed in units of base volume per unittime (e.g., gpm, m3/h, etc.).base pressure: a specified reference pressure to whic

28、h afluid volume at flowing conditions is reduced for thepurpose of billing and transfer accounting. It is generallytaken as 14.73 psia (101.560 kPa) by the gas industry inthe U.S.base temperature: a specified reference temperature towhich a fluid volume at flowing conditions is reducedfor the purpos

29、e of billing and transfer accounting. It isgenerally taken as 60F (15.56C) by the gas industry inthe U.S.base volume: volume of the fluid at base pressure andtemperature.flowing pressure: static pressure of the fluid at the flowingcondition.flowing temperature: the temperature of the fluid at theflo

30、wing condition.linearity: linearity refers to the constancy of K factor overa specified range, defined by either the pipe Reynoldsnumber or the flow rate. A typical liquid turbine meterperformance curve is shown in Fig. 1. The linear rangeof the turbine meter is usually specified by a banddefined by

31、 maximum and minimum K factors, withinwhich the K factor for the meter is assumed to be Kmean.The upper and lower limits of this range can be specifiedby the manufacturer as a function of maximum andminimum Reynolds number ranges, a flow rate rangeof a specified fluid, or other meter design limitati

32、onssuch as pressure, temperature, or installation effects.pipe Reynolds number: expressed by the equationReppvpDH9271pH9267vpDH9262(1)ASME MFC-222007Fig. 1 Typical Meter Performance CurveFlow range linearity, Application AFlow range linearity,Application BLinearity BLinearity AwhereD p diameter of t

33、he inlet pipe that is of the samenominal size as the metervpp average fluid velocity in the inlet pipeH9262 p dynamic viscosity of the fluidH9267 p density of the fluidrangeability or turndown: flowmeter rangeability is theratio of the maximum to minimum flow rates orReynolds number in the range ove

34、r which the metermeets a specified uncertainty and/or accuracy.repeatability of measurements (qualitative): the closeness ofagreement among a series of results obtained with thesame method on identical test material, under the sameconditions (i.e., same operator, same apparatus, samelaboratory, and

35、short intervals of time).reproducibility: the closeness of agreement betweenresults obtained when the conditions of measurementdiffer; for example, with respect to different test appara-tus, operators, facilities, time intervals, etc.Reynolds number: a dimensionless parameter expressingthe ratio bet

36、ween inertia and viscous forces.turbine meter: a flow measuring device with a rotor thatresponds to the velocity of flowing fluid in closed con-duit. The flowing fluid causes the rotor to move with atangential velocity that is directly linearly proportionalto the volumetric flow rate.3.2 SymbolsSee

37、Table 1.4 PRINCIPLE OF MEASUREMENT4.1 Measuring MechanismThe measuring mechanism consists of the rotor, rotorshafting, bearings, and the necessary supporting struc-ture (Figs. 2 and 3). The flowing fluid passing throughthe blades of the rotor, which are at an angle to thedirection of the flow, impar

38、ts a tangential force on theblades. This tangential force causes the rotation of therotor that is directly linearly proportional to the axial2flow rate through the meter. For ideal fluids and friction-less rotor, the rate of rotation is linearly proportional tothe axial flow velocity and the constan

39、t of proportional-ity is a function of the blade angle.4.2 Output and Readout Device4.2.1 The rate of revolution of the rotor is normallydetermined from the blade passing frequency or by othermeans that relates to the rate of rotation.4.2.2 Turbine meter output may be mechanical,electrical, electrom

40、echanical, optical, analog, and digital.The readout devices may be of any form suitable for theapplication.4.2.3 For electrical pulse output meters, the outputincludes the pulse detector system and all electrical con-nections necessary to transmit the indicated rotor revo-lutions outside the body fo

41、r uncorrected volumeregistration.5 SELECTION OF METER AND ACCESSORYEQUIPMENT FOR FLOW RATE DETERMINATIONFor proper selection and operation of the meter, thefollowing information may be necessary:(a) fluid properties of the flowing stream includingviscosity, vapor pressure, toxicity, corrosiveness, l

42、ubrica-tion properties, specific gravity, etc.(b) flow rate range and operational conditions includ-ing unidirectional or bidirectional flows and continuousor intermittent flows(c) performance characteristics that are required forthe application including linearity over a specified flowrange, repeat

43、ability at any flow rate, and improved lin-earity over a flow range(d) the flange rating, area classification, materials, anddimensions of the equipment used(e) available space for the meter installation and prov-ing facility, if required for the application(f) operating pressure ranges, acceptable

44、pressurelosses through the meter installation, and necessary con-sideration to avoid vaporization of the fluid while pass-ing through the meter(g) operating temperature range and the applicabilityof the automatic temperature compensation(h) effects of corrosive fluids and contaminants on themeter(i)

45、 amount and size of the suspended solids in theflowing stream including filtering equipment for themetering section(j) types of readout and printout devices, or desiredoutput system to be used for signal preamplificationand output units of the measurement as required(k) for multiple meter-run instal

46、lations and how ameter is taken in or out of service during operation ofthe entire systemASME MFC-222007Fig. 2 Schematic of Liquid Turbine Meter (Upstream-Downstream Stator)FlowUpstream statorRotor bladesBearingShaftEnd connectionMeter housingUpstream stator supportRotor hubPickupDownstream stator s

47、upportDownstream statorTable 1 SymbolsDimensions U.S. CustomarySymbol Quantity Note (1) SI Units UnitsG Specific gravity Dimensionless . . . . . .K Calibration factor (pulses/unit volume) L3pulses/m3pulses/ft3PaStatic pressure, absolute ML1T2Pa abs lbf/ft2absPgStatic pressure, gauge ML1T2Pa gage lbf

48、/ft2gageH9004P Meter pressure loss ML1T2Pa lbf/ft2q Volume flow rate L3T1m3/s ft3/hrV Liquid volume passed L3m3ft3M Liquid mass passed M kg lbmH9267 Mass density ML3kg/m3lbm/ft3f Frequency linearly related to rotational speed T1s1sec1PeEquilibrium pressure ML1T2Pa lbf/ft2VpAverage fluid velocity LT1

49、m/s ft/secGENERAL NOTE:b p subscript for base conditions of temperature, pressure, and fluid compositionf p subscript for flowing conditions of temperature, pressure, and fluid compositionp p subscript for inlet pipeeff p subscript for effective degreesNOTE:(1) Fundamental dimensions: M p mass; L p length; T p time.3ASME MFC-222007Fig. 3 Schematic of Liquid Turbine Meter (Cantilever Stator)FlowUpstream statorRotor hubBearingShaftEnd connectionMeter housingUpstream stator supportPickupDownstream stator supportDownstream statorRotor bladesFig. 4 Typical Turbine M