1、Orifice Metering of Natural Gas and Other Related Hydrocarbon FluidsConcentric, Square-edged Orifice MetersPart 3: Natural Gas ApplicationsAGA Report No. 3Part 3Manual of Petroleum Measurement StandardsChapter 14.3.3American Gas Association400 North Captiol Street, NWWashington, DC 20001American Pet
2、roleum Institute1220 L Street, NWWashington, DC 20005FOURTH EDITION, NOVEMBER 2013An American National StandardANSI/API MPMS Ch. 14.3.3/AGA Report No. 3, Part 3Special NotesThis AGA/API publication necessarily addresses problems of a general nature. With respect to particular circumstances, local, s
3、tate, and federal laws and regulations should be reviewed.Neither AGA and API nor any of AGAs or APIs employees, subcontractors, consultants, committees, or other assignees make any warranty or representation, either express or implied, with respect to the accuracy, completeness, or usefulness of th
4、e 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 of AGAs or APIs employees, subcontractors, consultants, or other assignees represent that use of
5、 this publication would not infringe upon privately owned rights.Users of this publication should not rely exclusively on the information contained in this document. Sound business, scientific, engineering, and safety judgment should be used in employing the information contained herein.This AGA/API
6、 publication may be used by anyone desiring to do so. Every effort has been made by AGA/API to assure the accuracy and reliability of the data contained in it; however, AGA/API makes no representation, warranty, or guarantee in connection with this publication and hereby expressly disclaims any liab
7、ility or responsibility for loss or damage resulting from its use or for the violation of any authorities having jurisdiction with which this publication may conflict.This AGA/API publication is published to facilitate the broad availability of proven, sound engineering and operating practices. It i
8、s not intended to obviate the need for applying sound engineering judgment regarding when and where this publication should be utilized. The formulation and publication of this AGA/API publication is not intended in any way to inhibit anyone from using any other practices.Any manufacturer marking eq
9、uipment or materials in conformance with the marking requirements of an API standard is solely responsible for complying with all the applicable requirements of that standard. API does not represent, warrant, or guarantee that such products do in fact conform to the applicable API standard.All right
10、s reserved. No part of this work may be reproduced, translated, stored in a retrieval system, or transmitted by any means, electronic, mechanical, photocopying, recording, or otherwise, without prior written permission from either the American Gas Association, 400 N. Capitol St., NW, Washington, DC
11、20001 or API Publishing Services, 1220 L Street, NW, Washington, DC 20005.Copyright 2013 American Gas Association and American Petroleum InstituteForewordNothing contained in this AGA/API publication is to be construed as granting any right, by implication or otherwise, for the manufacture, sale, or
12、 use of any method, apparatus, or product covered by letters patent. Neither should anything contained in the publication be construed as insuring anyone against liability for infringement of letters patent.This document was produced under API standardization procedures that ensure appropriate notif
13、ication and participation in the developmental process and is designated as API Manual of Petroleum Measurement Standard (MPMS) Chapter 14.3.3 and AGA Report No. 3, Part 3. Questions concerning the procedures under which this publication was developed should be directed in writing to the Director of
14、 Standards, American Petroleum Institute, 1220 L Street, NW, Washington, DC 20005. Questions concerning the interpretation of the content of this publication should be directed to the Director of Standards, American Petroleum Institute, 1220 L Street, NW, Washington, DC 20005 and to the Vice Preside
15、nt, 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 permission to reproduce or translate all or any part of the material published herein should also
16、be addressed to the Director of Standards, American Petroleum Institute (as above) or the Vice President, Operations and Engineering, American Gas Association (as above).Shall: As used in a standard, “shall” denotes a minimum requirement in order to conform to the specification.Should: As used in a
17、standard, “should” denotes a recommendation or that which is advised but not required in order to conform to the specification.This AGA/API publication is reviewed and revised, reaffirmed, or withdrawn at least every five years. A one-time extension of up to two years may be added to this review cyc
18、le. Status of the publication can be ascertained from the API Standards Department, telephone (202) 682-8000. A catalog of API publications and materials is published annually by API, 1220 L Street, NW, Washington, DC 20005.A catalog of AGA Operations and Engineering publications, which is published
19、 and updated as needed and can be obtained by contacting AGA Operations and Engineering Department, phone (202) 824-7000 or web site http:/www.aga.org/Pages/contact_us.aspx. Suggested revisions are invited and should be submitted to the Standards Department, API, 1220 L Street, NW, Washington, DC 20
20、005, standardsapi.org or Operations and Engineering Department, American Gas Association, 400 North Capitol Street, NW, Washington, DC 20001, http:/www.aga.org/Pages/contact_us.aspx.iiiContentsPage1 Scope . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
21、 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11.1 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11.2 Definition of Natural Gas . . . . . . . . . . . . .
22、 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11.3 Basis for Equations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11.4 Expansion Factor Appli
23、cation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 Normative References. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 Symbo
24、ls, Units, and Terminology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23.1 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
25、. . . . . . . . . . 23.2 Symbols and Units . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23.3 Terminology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
26、. . . . . . . . . . . . . . . . . . . . . . . . . . . . 44 Flow Measurement Equations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54.1 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
27、 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54.2 Equations for Mass Flow of Natural Gas . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54.3 Equations for Volume Flow of Natural Gas . . . . . . . . . .
28、 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64.4 Volume Conversion from Reference Base to Base Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85 Flow Equation Components Requiring Additional Computation . . . . . . . . . . . .
29、. . . . . . . . . . . . . . . . . . . . . 95.1 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95.2 Diameter Ratio () . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
30、. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95.3 Coefficient of Discharge for Flange-tapped Orifice Meter Cd (FT) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95.4 Velocity of Approach Factor (Ev) . . . . . . . . . . . . . . . . . . . . . . .
31、. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 115.5 Reynolds Number (ReD) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 125.6 Expansion Factor (Y). . . . . . . . . . . . . . . . . . . . .
32、. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 136 Gas Properties . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 166.1 General . . . . . . . . . . . .
33、 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 166.2 Physical Properties . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
34、 . 166.3 Compressibility . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 166.4 Relative Density. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
35、 . . . . . . . . . . . . . . . . . . . 186.5 Density of Fluid at Flowing Conditions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20Annex A (informative) Adjustments for Instrument Calibration . . . . . . . . . . . . . . . . . . . . . . .
36、. . . . . . . . . . . . . . . 24Annex B (informative) Factors Approach . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30Annex C (informative) Flow Calculation Examples . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
37、 . . . . . . . . . . . . . . 33Annex D (informative) Pipe Tap Orifice Metering . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41Annex E (informative) SI Conversions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
38、 . . . . . . . . . . . . . . . . . 42Annex F (informative) Development of Constants for Flow Equations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44Annex G (informative) Buckingham and Bean Empirical Expansion Factor (Y ) for Flange-tapped Orifice Meters. . . . . . . . . . . . .
39、 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50Bibliography . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54vContentsPageTables1 Lin
40、ear Coefficient of Thermal Expansion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10A.1 Water Density Based on Patterson and Morris Equation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28E.1 Volume Reference
41、 Conditions for Custody Transfer Operations: Natural Gas Volume . . . . . . . . . . . . . . 42E.2 Energy Reference Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42E.3 Heating Value Reference Conditions . . . . . .
42、 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43G.1 Comparison Between Equation (35) and Equation (G.3). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53viviiIntroductionAPI MPMS Chapter 14.3.3/AGA Report No. 3, Par
43、t 3 is organized as follows: Symbols and units are first defined, the basic flow equation is presented, then key equation components are defined, and finally the gas properties applicable to orifice metering of natural gas are developed. Factors to compensate for meter calibration and location are i
44、ncluded in Annex A. The factor approach to orifice measurement is included in Annex B. Annex F covers derivation of constants. The user is cautioned that the symbols may be different from those used in previous orifice metering standards.1Orifice Metering of Natural Gas and Other Related Hydrocarbon
45、 FluidsConcentric, Square-edged Orifice MetersPart 3: Natural Gas Applications1 Scope1.1 GeneralThis part of API MPMS Ch. 14.3/AGA Report No. 3 has been developed as an application guide for the calculation of natural gas flow through a flange-tapped, concentric orifice meter, using the U.S. customa
46、ry (USC) inch-pound system of units. For applications involving international system (SI) of units, a conversion factor can be applied to the results (Qm, Qv, or Qb) determined from the equations in 4.3. Intermediate conversion of units will not necessarily produce consistent results. As an alternat
47、ive, the more universal approach specified in API MPMS Ch. 14.3.1/AGA Report No. 3, Part 1 can be used. The meter has to be constructed and installed in accordance with API MPMSCh. 14.3.2/AGA Report No. 3, Part 2.1.2 Definition of Natural GasAs used in this document, the term natural gas applies to
48、fluids that for all practical purposes are considered to include both pipeline and production quality gas with single-phase flow and mole percentage ranges of components as given in Table 1 of API MPMS Ch. 14.2/AGA Report No. 8. For other hydrocarbon mixtures, the more universal approach specified i
49、n API MPMS Ch. 14.3.1/AGA Report No. 3, Part 1 may be more applicable. Diluents or mixtures other than those stipulated in API MPMS Ch. 14.2/AGA Report No. 8 may increase the flow measurement uncertainty.1.3 Basis for EquationsThe computation methods used in this document are consistent with those developed in API MPMS Ch. 14.3.1/AGA Report No. 3, Part 1 and include the Reader-Harris/Gallagher (RG) equation for flange-tapped orifice meter discharge coefficient. The equation has been modified to reflect the more common units of the USC inch-pound system. 1.4 Expansion Factor Appl
