API MPMS 14.3.1-2012 Orifice Metering of Natural Gas and Other Related Hydrocarbon Fluids-Concentric Square-edged Orifice Meters Part 1 General Equations and Uncertainty Guidelines.pdf

1、Orifice Metering of Natural Gas and Other Related Hydrocarbon FluidsConcentric, Square-edged Orifice MetersPart 1: General Equations and Uncertainty GuidelinesAGA Report No. 3Part 1Manual of Petroleum Measurement StandardsChapter 14.3.1American Gas Association400 North Captiol Street, NWWashington,

2、DC 20001American Petroleum Institute1220 L Street, NWWashington, DC 20005FOURTH EDITION, SEPTEMBER 2012ERRATA, JULY 2013An American National StandardANSI/API MPMS Ch. 14.3.1/AGA Report No. 3, Part 1Special NotesThis AGA/API publication necessarily addresses problems of a general nature. With respect

3、 to particularcircumstances, local, state, and federal laws and regulations should be reviewed.Neither AGA and API nor any of AGAs or APIs employees, subcontractors, consultants, committees, or otherassignees make any warranty or representation, either express or implied, with respect to the accurac

4、y,completeness, or usefulness of the information contained herein, or assume any liability or responsibility for any use,or the results of such use, of any information or process disclosed in this publication. Neither AGA and API nor any ofAGAs or APIs employees, subcontractors, consultants, or othe

5、r assignees represent that use of this publicationwould not infringe upon privately owned rights.This AGA/API publication may be used by anyone desiring to do so. Every effort has been made by AGA/API toassure the accuracy and reliability of the data contained in it; however, AGA/API makes no repres

6、entation, warranty,or guarantee 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 jurisdiction with which this publication mayconflict.This AGA/API publication is

7、published to facilitate the broad availability of proven, sound engineering and operatingpractices. It is not intended to obviate the need for applying sound engineering judgment regarding when and wherethis publication should be utilized. The formulation and publication of this AGA/API publication

8、is not intended in anyway 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 with all the applicable requirements of that standard. API does not represent,

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11、is to be construed as granting any right, by implication or otherwise, forthe manufacture, 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 pa

12、tent.This document was produced under API standardization procedures that ensure appropriate notification andparticipation in the developmental process and is designated as API Manual of Petroleum Measurement Standard(MPMS) Chapter 14.3.1 and AGA Report No. 3, Part 1. Questions concerning the proced

13、ures under which thispublication was developed should be directed in writing to the Director of Standards, American Petroleum Institute,1220 L Street, NW, Washington, DC 20005. Questions concerning the interpretation of the content of this publicationshould be directed to the Director of Standards,

14、American Petroleum Institute, 1220 L Street, NW, Washington, DC20005 and to the Vice President, Operations and Engineering, American Gas Association, 400 N. Capitol Street, NW,Washington, DC 20001, and shall be handled in accordance with APIs Procedures for Standards Development.Requests for permiss

15、ion to reproduce or translate all or any part of the material published herein should also beaddressed to the Director of Standards, American Petroleum Institute (as above) or the Vice President, Operationsand Engineering, American Gas Association (as above).This AGA/API publication is reviewed and

16、revised, reaffirmed, or withdrawn at least every five years. A one-timeextension of up to two years may be 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 publishedannu

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18、 Suggested revisions are invited and should be submitted to the Standards Department, API, 1220 L Street, NW,Washington, DC 20005, standardsapi.org or Operations and Engineering Department, American Gas Association,400 North Capitol Street, NW, Washington, DC 20001, http:/www.aga.org/Pages/contact_u

19、s.aspx.iiiContentsPage1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11.1 Scope . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

20、. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11.2 Organization of Standard . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 Normative References. . . . . . . . . . . . . . . . . . . . . . . . .

21、 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 Terms, Definitions, and Symbols. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33.1 Terms and Definitions. . . . . . . . . . . . . . . .

22、 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33.2 Symbols . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74 Field of Applicat

23、ion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84.1 Applicable Fluids. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

24、. . . . . . . 84.2 Types of Meters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 94.3 Uncertainty of Measurement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

25、 . . . . . . . . . . . . . . . . . . . 105 Method of Calculation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 106 Orifice Flow Equation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

26、. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 106.1 Velocity of Approach Factor (Ev) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 126.2 Orifice Plate Bore Diameter (d). . . . . . . . . . . . . . . . . . . . . .

27、. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 126.3 Meter Tube Internal Diameter (D). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 127 Empirical Coefficient of Discharge . . . . . . . . . . . . . .

28、 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 137.1 Regression Database . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 147.2 Empirical Coefficient of Discharge Equation f

29、or Flange-tapped Orifice Meters . . . . . . . . . . . . . . . . . . . . 157.3 Reynolds Number (ReD) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 167.4 Flow Conditions. . . . . . . . . . . . . . . . . . . . . . . .

30、 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 167.5 Pulsating Flow . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 178 Empirical Expansion Factor (

31、Y ) for Flange-tapped Orifice Meters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 198.1 Upstream Expansion Factor (Y1) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 208.2 Downstream Expansion Factor (Y2). . . .

32、. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 219 In-situ Calibration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 229.1 General . . . . . . .

33、. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 229.2 Meter Factor (MF). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

34、 . . . . . . 2210 Fluid Physical Properties . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2310.1 Viscosity () . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

35、. . . . . . . . . . . . . . . . . . . . . . . 2310.2 Density (t,p, b) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2310.3 Isentropic Exponent (). . . . . . . . . . . . . . . . . . . . . . . . . . . . .

36、 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2411 Unit Conversion Factors. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2411.1 Orifice Flow Equation . . . . . . . . . . . . . . . . .

37、. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2411.2 Reynolds Number Equation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2511.3 Expansion Factor Equation . . . .

38、 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2511.4 Flow Rate per Unit of Time Conversion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2512 Practical Uncertainty Gui

39、delines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2812.1 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

40、 2812.2 Uncertainty Over a Flow Range . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2812.3 Uncertainty of Flow Rate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

41、. . . . . . . . . . 2812.4 Typical Uncertainties. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3112.5 Example Uncertainty Calculations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

42、. . . . . . . . . . . . . . . . . . . . 37vContentsPageAnnex A (informative) Discharge Coefficients for Flange-tapped Orifice Meters . . . . . . . . . . . . . . . . . . . . . . . 40Annex B (informative) Adjustments for Instrument Calibration and Use . . . . . . . . . . . . . . . . . . . . . . . . .

43、. . . . . 51Annex C (informative) Buckingham and Bean Empirical Expansion Factor (Y) for Flange-tapped Orifice Meters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52Bibliography . . . . . . . . . . . . .

44、 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56Figures1 Orifice Tapping Location . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

45、 . 52 Orifice Meter Elements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93 Contribution to Flow Error Due to Differential Pressure Instrumentation . . . . . . . . . . . . . . . . . . . . . . . . . 294 Empiri

46、cal Coefficient of Discharge: Uncertainty at Infinite Reynolds Number . . . . . . . . . . . . . . . . . . . . . 325 Relative Change in Uncertainty: Dependence on Reynolds Number . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 326 Practical Uncertainty Levels. . . . . . . . . . . . . . . .

47、. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34Tables1 Linear Coefficient of Thermal Expansion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 132 Orifice Flow Rate Equation: Unit Conversion Fact

48、or (N1). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 263 Reynolds Number Equation: Unit Conversion Factor (N2). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 274 Empirical Expansion Factor Equation: Unit Conversion Factor (N3) . . . . . . .

49、 . . . . . . . . . . . . . . . . . . . . . . 275 Uncertainty Statement for Empirical Expansion Factor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 336 Example Uncertainty Estimate for Liquid Flow Calculation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 387 Example Uncertainty Estimate for Natural Gas Flow Calculation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39A.1 Discharge Coefficients for Flange-tapped Orifice Meters: Nominal 2-in. (50-mm) MeterD = 1.939 in. (49.25 mm) . . . . . . . . . . .