ISO/TR 9464 TECHNICAL REPORT Second edition 2008-05-15 `,,```,,,,````-`-`,,`,,`,`,,` - Guidelines for the use of ISO 5167:2003 Lignes directrices pour l'utilisation de l'ISO 5167:2003 Reference number ISO/TR 9464:2008(E) Copyright International Organization for Standardization Provided by IHS under license with ISO No reproduction or networking permitted without license from IHS © ISO 2008 Not for Resale ISO/TR 9464:2008(E) PDF disclaimer This PDF file may contain embedded typefaces In accordance with Adobe's licensing policy, this file may be printed or viewed but shall not be edited unless the typefaces which are embedded are licensed to and installed on the computer performing the editing In downloading this file, parties accept therein the responsibility of not infringing Adobe's licensing policy The ISO Central Secretariat accepts no liability in this area Adobe is a trademark of Adobe Systems Incorporated `,,```,,,,````-`-`,,`,,`,`,,` - Details of the software products used to create this PDF file can be found in the General Info relative to the file; the PDF-creation parameters were optimized for printing Every care has been taken to ensure that the file is suitable for use by ISO member bodies In the unlikely event that a problem relating to it is found, please inform the Central Secretariat at the address given below COPYRIGHT PROTECTED DOCUMENT © ISO 2008 All rights reserved Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from either ISO at the address below or ISO's member body in the country of the requester ISO copyright office Case postale 56 • CH-1211 Geneva 20 Tel + 41 22 749 01 11 Fax + 41 22 749 09 47 E-mail copyright@iso.org Web www.iso.org Published in Switzerland ii Copyright International Organization for Standardization Provided by IHS under license with ISO No reproduction or networking permitted without license from IHS © ISO 2008 – All rights reserved Not for Resale ISO/TR 9464:2008(E) Contents Page Foreword iv Introduction v `,,```,,,,````-`-`,,`,,`,`,,` - Scope Normative references Terms and definitions How the structure of this guide relates to ISO 5167:2003 (all parts) 5.1 5.2 5.3 5.4 Guidance on the use of ISO 5157:2003 (all parts) Guidance specific to the use of ISO 5167-1:2003 Guidance specific to the use of ISO 5167-2:2003 Guidance specific to the use of ISO 5167-3:2003 23 Guidance specific to the use of ISO 5167-4:2003 24 6.1 6.2 6.3 6.4 6.5 Information of a general nature relevant to the application of ISO 5167:2003 (all parts) 25 Secondary instrumentation 25 Measurement of pressure and differential pressure 27 Measurement of temperature 31 Determination of density 35 Electrical supply and electrical installations 40 Annex A (informative) Principles of measurement and computation 41 Annex B (informative) Computation of compressibility factor for natural gases 57 Annex C (informative) Orifice plate assembly 59 Bibliography 68 iii © ISO 2008 – All rights reserved Copyright International Organization for Standardization Provided by IHS under license with ISO No reproduction or networking permitted without license from IHS Not for Resale ISO/TR 9464:2008(E) Foreword ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies) The work of preparing International Standards is normally carried out through ISO technical committees Each member body interested in a subject for which a technical committee has been established has the right to be represented on that committee International organizations, governmental and non-governmental, in liaison with ISO, also take part in the work ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part The main task of technical committees is to prepare International Standards Draft International Standards adopted by the technical committees are circulated to the member bodies for voting Publication as an International Standard requires approval by at least 75 % of the member bodies casting a vote In exceptional circumstances, when a technical committee has collected data of a different kind from that which is normally published as an International Standard (“state of the art”, for example), it may decide by a simple majority vote of its participating members to publish a Technical Report A Technical Report is entirely informative in nature and does not have to be reviewed until the data it provides are considered to be no longer valid or useful Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights ISO shall not be held responsible for identifying any or all such patent rights ISO/TR 9464 was prepared by Technical Committee ISO/TC 30, Measurement of fluid flow in closed conduits, Subcommittee SC 2, Pressure differential devices This second edition cancels and replaces the first edition (ISO/TR 9464:1998), which has been technically revised `,,```,,,,````-`-`,,`,,`,`,,` - iv Copyright International Organization for Standardization Provided by IHS under license with ISO No reproduction or networking permitted without license from IHS © ISO 2008 – All rights reserved Not for Resale ISO/TR 9464:2008(E) Introduction The objective of this Technical Report is to assist users of ISO 5167, which was published in 2003 in four parts Guidance on particular clauses of ISO 5157:2003 is given Some clauses of ISO 5167:2003 (parts to 4) are not commented upon and the corresponding clause numbers are therefore omitted from this Technical Report, except when it has been thought to be useful to keep a continuous numbering of paragraphs `,,```,,,,````-`-`,,`,,`,`,,` - v © ISO 2008 – All rights reserved Copyright International Organization for Standardization Provided by IHS under license with ISO No reproduction or networking permitted without license from IHS Not for Resale `,,```,,,,````-`-`,,`,,`,`,,` - Copyright International Organization for Standardization Provided by IHS under license with ISO No reproduction or networking permitted without license from IHS Not for Resale TECHNICAL REPORT ISO/TR 9464:2008(E) Guidelines for the use of ISO 5167:2003 Scope The objective of this Technical Report is to provide guidance on the use of ISO 5167:2003 (all parts) ISO 5167:2003 is an International Standard for flow measurement based on the differential pressure generated by a constriction introduced into a circular conduit (see ISO 5167-1:2003, 5.1) It presents a set of rules and requirements based on theory and experimental work undertaken in the field of flow measurement For a more detailed description of the scope, reference should be made to ISO 5167-1:2003, Clause Definitions and symbols applicable to this Technical Report are given in ISO 5167-1:2003, Clauses and Neither ISO 5167-1:2003 nor this Technical Report give detailed theoretical background, for which reference should be made to any general textbook on fluid flow With the application of the rules and requirements set out in ISO 5167-1:2003, it is practicable to achieve flow measurement within an uncertainty of approximately % of the calculated flowrate The constraints applicable to each of the primary devices described in ISO 5167:2003 (parts to 4) need to be given consideration before determining the most suitable type for a particular application Parts to can also be used to form the basis for preliminary design of a metering system The information necessary for detailed design, manufacture and final check is specified in the clauses and paragraphs of ISO 5167:2003 (parts to 4) Secondary instrumentation is not covered by ISO 5167-1:2003, but Clause of this Technical Report makes normative reference to ISO 2186 Normative references The following referenced documents are indispensable for the application of this document For dated references, only the edition cited applies For undated references, the latest edition of the referenced document (including any amendments) applies ISO 2186, Fluid flow in closed conduits — Connections for pressure signal transmissions between primary and secondary elements ISO/TR 3313:1998, Measurement of fluid flow in closed conduits — Guidelines on the effects of flow pulsations on flow-measurement instruments ISO 4006, Measurement of fluid flow in closed conduits — Vocabulary and symbols ISO 5167-1:2003, Measurement of fluid flow by means of pressure differential devices inserted in circular cross-section conduits running full — Part 1: General principles and requirements `,,```,,,,````-`-`,,`,,`,`,,` - ISO 5167-2:2003, Measurement of fluid flow by means of pressure differential devices inserted in circular cross-section conduits running full — Part 2: Orifice plates ISO 5167-3:2003, Measurement of fluid flow by means of pressure differential devices inserted in circular cross-section conduits running full — Part 3: Nozzles and Venturi nozzles © ISO 2008 – All rights reserved Copyright International Organization for Standardization Provided by IHS under license with ISO No reproduction or networking permitted without license from IHS Not for Resale ISO/TR 9464:2008(E) ISO 5167-4:2003, Measurement of fluid flow by means of pressure differential devices inserted in circular cross-section conduits running full — Part 4: Venturi tubes Terms and definitions For the purposes of this document, the terms and definitions given in ISO 4006 apply How the structure of this guide relates to ISO 5167:2003 (all parts) Clause of this Technical Report sets out the guidance specific to each of the four parts of ISO 5167:2003: ⎯ 5.1 covers part 1; ⎯ 5.2 covers part 2; ⎯ 5.3 covers part 3; ⎯ 5.4 covers part Subsequent subclause numbering relates to the clauses in each of the parts Hence, 5.1.1 covers Clause in part 1; 5.4.3.1.1 covers Subclause 3.1.1 in part Guidance applicable to all four parts is given in Clause Guidance on the use of ISO 5157:2003 (all parts) 5.1 Guidance specific to the use of ISO 5167-1:2003 5.1.1 Scope `,,```,,,,````-`-`,,`,,`,`,,` - No comments on this clause 5.1.2 Normative references No comments on this clause 5.1.3 Terms and definitions No comments on this clause 5.1.4 Symbols and subscripts No comments on this clause 5.1.5 5.1.5.1 Principle of the method of measurement and computation Principle of the method of measurement No comments on this subclause Copyright International Organization for Standardization Provided by IHS under license with ISO No reproduction or networking permitted without license from IHS © ISO 2008 – All rights reserved Not for Resale ISO/TR 9464:2008(E) 5.1.5.2 Method of determination of the diameter ratio of the standard primary device See Annex A of this Technical Report 5.1.5.3 Computation of flowrate The equations to be used to determine the flowrate of a measuring system are given in ISO 5167-1:2003, Clause Some results of these calculations will be fixed with installation dimensions and will only need to be computed once Other calculations will need to be repeated for every flow measurement point Annex A gives worked examples of the iterative computations shown in ISO 5167-1:2003, Annex A 5.1.5.4 Determination of density, pressure and temperature 5.1.5.4.1 General No comments on this subclause 5.1.5.4.2 Density For details on density measurement, see 6.4 For details on density computation, see Annex B of this Technical Report 5.1.5.4.3 Static pressure No comments on this subclause 5.1.5.4.4 Temperature The computation of temperature decrease resulting from expansion of the fluid through the primary device requires knowledge of the Joule-Thomson coefficient The coefficient is a function of temperature, pressure and gas composition The calculation can be carried out using an equation of state (see, in Annex B, the “detailed method” using molar composition analysis) or by the use of an approximation valid for natural gas mixtures that are not too rich, and when p and T are in the range given below In the last case, the coefficient is a function of p and T alone Provided that, in the molar composition of the natural gas, methane is greater than 80 %, the temperature is in the range °C to 100 °C and the absolute static pressure is in the range 100 kPa to 20 MPa (1 bar to 200 bar) µ JT = 0,35 − 0,001 42t ( + 0,231 − 0,002 94t + 0,000 0136t ) (0,998 + 0,000 41p − 0,000 111 5p + 0,000 000 3p ) (1) where t is the temperature of the fluid, in degrees Celsius (°C); p is the absolute static pressure of the fluid, in bar `,,```,,,,````-`-`,,`,,`,`,,` - µJT is the Joule-Thomson coefficient, in kelvin per bar (K/bar); The uncertainty was determined from the differences between this equation and the Joule-Thomson coefficient of 14 common natural gases and is given by t ⎞ ⎛ U = 0,066 ⎜ − ⎟ 200 ⎝ ⎠ for p u 70 bar (7 MPa) © ISO 2008 – All rights reserved Copyright International Organization for Standardization Provided by IHS under license with ISO No reproduction or networking permitted without license from IHS (2) Not for Resale ISO/TR 9464:2008(E) and t ⎞ ⎡ (290 − t ) ⎛ 1 ⎞ ⎤ ⎛ U = 0,066 ⎜ − − ⎟⎥ ⎢1 − ⎜ 200 ⎟⎠ ⎢⎣ ⎝ ⎝ 70 p ⎠ ⎦⎥ for p > 70 bar (7 MPa) (3) where U is the (expanded) uncertainty in the Joule-Thomson coefficient (K/bar) NOTE If an orifice plate with β = 0,6 has a differential pressure ∆p = 0,5 bar, the uncertainty in the Joule-Thomson coefficient corresponds to an uncertainty in flowrate in the range from 0,001 % to 0,009 %, depending on the temperature, the pressure and the gas composition 5.1.6 General requirements for the measurements 5.1.6.1 Primary device 5.1.6.1.1 No comments on this subclause 5.1.6.1.2 No comments on this subclause 5.1.6.1.3 devices Table 1, whilst not exhaustive, lists materials most commonly used for the manufacture of primary Table — Steels commonly used for the manufacture of primary devices Stainless steels High elastic limit stainless steel AISI BS 970 AFNOR DIN 304 304-S15 Z6CN18-09 1.4301 316 316-S16 Z6CND17-11 1.4401 420 420-S37 Z30C13 Table gives the mean linear expansion coefficient, elasticity moduli and yield stresses for the materials of Table according to their AISI designation Table — Characteristics of commonly used steels Mean linear expansion coefficient Elasticity modulus Yield stress K−1 Pa Pa 304 17 × 10−6 193 × 109 215 × 106 316 16 × 10−6 193 × 109 230 × 106 420 10 × 10−6 200 × 109 494 × 106 AISI designation between °C and 100 °C The values given in Table vary with both temperature and the treatment process of the steel For precise calculations, it is recommended that the data are obtained from the manufacturer When the primary device under operating conditions is at a different temperature from the one at which the diameter “d” was determined (this temperature is referred to as the reference or calibration temperature), the expansion or contraction of the primary device should be calculated The corrected diameter “d” to be used in the computation of diameter ratio and flowrate should be calculated using Equation (4), assuming there is no restraint due to the mounting: `,,```,,,,````-` Copyright International Organization for Standardization Provided by IHS under license with ISO No reproduction or networking permitted without license from IHS © ISO 2008 – All rights reserved Not for Resale ISO/TR 9464:2008(E) Key a ε and p1 have to be known for compressible fluids only b For incompressible fluids, ε = and no loop is necessary c For the first step, E1 = but proceed to “NO”, except for classical Venturi tubes and Venturi nozzles Figure A.4 — Flowchart example — Computation of pressure ∆p 56 `,,```,,,,````-`-`,,`,,`,`,,` - Copyright International Organization for Standardization Provided by IHS under license with ISO No reproduction or networking permitted without license from IHS © ISO 2008 – All rights reserved Not for Resale ISO/TR 9464:2008(E) Annex B (informative) Computation of compressibility factor for natural gases B.1 Calculation of density, ρ The density of a gas may be calculated by means of either of the following equations: ρ= ρ= pM RuTZ (B.1) ρ pT0 Z (B.2) p 0TZ where Z is the compressibility factor; ρ is the density; M is the molecular weight of the gas; The subscript refers to a reference state of temperature and pressure Z is a function of the composition of the gas B.2 Calculation of compressibility factor, Z `,,```,,,,````-`-`,,`,,`,`,,` - Ru is the universal gas constant Modern methods for the computation of Z aim to cover the entire range of transmission metering conditions and gas compositions These are described in ISO 12213 [2] ISO 12213 has three parts: 1) introduction and guidelines; 2) calculation using molar composition analysis; 3) calculation using physical properties All of these parts were published in 2006 and are based on AGA Report Number [7] The calculation of Z using molar composition analysis, also known as the “detailed method”, uses up to 21 components and has been thoroughly evaluated for a broad range of typical natural gas pipeline temperatures, pressures and gas compositions (see Reference [9]) High accuracy measurements on five gravimetrically prepared reference natural gas mixtures were made by four leading laboratories in Europe and North America The gas compositions were selected by European and North American pipeline company representatives, and are characteristic of a wide range of commercial natural gases found world-wide The calculation of Z using physical properties, known as the “gross method”, uses a simplified input data set comprising any three from superior (gross) calorific value (heating value), relative density, carbon dioxide content and nitrogen content, together with pressure and temperature With this limited information, the equation predicts Z within the respective pressure and temperature ranges of MPa to 12 MPa (0 bar to 120 bar) and 265 K to 335 K (−8 °C to 62 °C) with an accuracy of about 0,1 %, about the same as the detailed method 57 © ISO 2008 – All rights reserved Copyright International Organization for Standardization Provided by IHS under license with ISO No reproduction or networking permitted without license from IHS Not for Resale ISO/TR 9464:2008(E) The detailed and gross calculation methods have also been published in Technical Monographs by the Groupe Européen de Recherches Gazières (GERG) and are known as the Master (or Molar) GERG-88 Virial Equation and Standard (or Simplified) GERG-88 Virial Equation (SGERG) Consistent thermophysical property calculations over a range of pipeline operating conditions are also needed for general orifice meter calibrations using sonic nozzles and cross-meter checking The GRI/AGA8 detail equation provides highly accurate, internally consistent derived thermophysical properties at standard pipeline operating conditions These properties include the speed of sound, heat capacity, enthalpy, and entropy required for sonic nozzle and other metering calculations used to evaluate and calibrate orifice, turbine and ultrasonic meters It is not recommended that the SGERG equation be used for calculating derived thermophysical properties `,,```,,,,````-`-`,,`,,`,`,,` - 58 Copyright International Organization for Standardization Provided by IHS under license with ISO No reproduction or networking permitted without license from IHS © ISO 2008 – All rights reserved Not for Resale ISO/TR 9464:2008(E) Annex C (informative) Orifice plate assembly Recommended orifice plate assemblies are illustrated below `,,```,,,,````-`-`,,`,,`,`,,` - 59 © ISO for 2008 – All rights reserved Copyright International Organization Standardization Provided by IHS under license with ISO No reproduction or networking permitted without license from IHS Not for Resale `,,```,,,,````-`-`,,`,,`,`,,` - ISO/TR 9464:2008(E) Key raised face (RF) flange gasket orifice plate Figure C.1 — Standard RF orifice flange assembly 60 Copyright International Organization for Standardization Provided by IHS under license with ISO No reproduction or networking permitted without license from IHS © ISO 2008 – All rights reserved Not for Resale ISO/TR 9464:2008(E) Key raised face (RF) flange ‘O’ rings orifice plate dowel pins (for location) Figure C.2 — Dowelled orifice flange assembly `,,```,,,,````-`-`,,`,,`,`,,` - © ISO 2008 – All rights reserved Copyright International Organization for Standardization Provided by IHS under license with ISO No reproduction or networking permitted without license from IHS Not for Resale 61 ISO/TR 9464:2008(E) Key `,,```,,,,````-`-`,,`,,`,`,,` - raised face (RF) flange gasket orifice plate (locates on flange RF outside diameter) Figure C.3 — Orifice flange assembly 62 Copyright International Organization for Standardization Provided by IHS under license with ISO No reproduction or networking permitted without license from IHS © ISO 2008 – All rights reserved Not for Resale ISO/TR 9464:2008(E) Key raised face (RF) flange gasket orifice plates (locates in flange face recess) Figure C.4 — Tongued faced orifice flange assembly `,,```,,,,````-`-`,,`,,`,`,,` - 63 © ISO 2008 – All rights reserved Copyright International Organization for Standardization Provided by IHS under license with ISO No reproduction or networking permitted without license from IHS Not for Resale ISO/TR 9464:2008(E) Key raised face (RF) flange gasket integral carrier Figure C.5 — Integral carrier orifice flange assembly 64 Copyright International Organization for Standardization Provided by IHS under license with ISO No reproduction or networking permitted without license from IHS `,,```,,,,````-`-`,,`,,`,`,,` - © ISO 2008 – All rights reserved Not for Resale ISO/TR 9464:2008(E) `,,```,,,,````-`-`,,`,,`,`,,` - Key single chamber orifice body orifice plate locking nut upstream sealring sealing bar downstream sealring ‘O’ ring locking bar winding mechanism to remove orifice plate Figure C.6 — Single chamber orifice assembly 65 © ISO 2008 – All rights reserved Copyright International Organization for Standardization Provided by IHS under license with ISO No reproduction or networking permitted without license from IHS Not for Resale ISO/TR 9464:2008(E) Key ring type joint (RTJ) flange orifice plate (integral male RTJ) `,,```,,,,````-`-`,,`,,`,`,,` - Figure C.7 — Standard RTJ orifice flange assembly 66 Copyright International Organization for Standardization Provided by IHS under license with ISO No reproduction or networking permitted without license from IHS © ISO 2008 – All rights reserved Not for Resale ISO/TR 9464:2008(E) `,,```,,,,````-`-`,,`,,`,`,,` - Key ring type joint (RTJ) flange ring type joint gasket orifice plate (integral female RTJ) Figure C.8 — Standard RTJ orifice flange assembly 67 © ISO 2008 – All rights reserved Copyright International Organization for Standardization Provided by IHS under license with ISO No reproduction or networking permitted without license from IHS Not for Resale ISO/TR 9464:2008(E) [1] ISO 5168:2005, Measurement of fluid flow — Procedures for the evaluation of uncertainties [2] ISO 12213 (all parts), Natural gas — Calculation of compression factor [3] ISO/IEC Guide 98-31) , Uncertainty of measurement — Part 3: Guide to the expression of uncertainty in measurement (GUM:1995) [4] IEC 60079-0:2007, Explosive atmospheres — Part 0: Equipment — General requirements [5] IEC 60584 (all parts), Thermocouples [6] IEC 60751, Industrial platinum resistance thermometer sensors [7] AGA Report Number 8, Compressibility factor of natural gas and related hydrocarbon gases American Gas Association, January 1994 [8] BRAIN, T.J.S and REID, J Measurement of orifice plate edge sharpness Measurement and Control, 6, 1973, pp 377-383 [9] GERG Technical Monograph, High Accuracy Compressibility Factor Calculation for Natural Gases and Similar Mixtures by Use of a Truncated Virial Equation GERG TM2 1988 [10] Matheson Gas Products, The Matheson unabridged gas data book East Rutherford, New Jersey, 1974 [11] MILLER, R.W Flow measurement engineering handbook Third edition, 1996 [12] NORMAN, R., RAWAT, M.S and JEPSON, P Buckling and eccentricity effects on orifice metering accuracy International Gas Research Conference, 1983 [13] READER-HARRIS, M.J., GIBSON, J., HODGES, D., NICHOLSON, I and RUSHWORTH, R The performance of flow nozzles at high Reynolds number In: Proc 14th International Flow Measurement Conference, FLOMEKO 14, Sandton, South Africa, September 2007 [14] SAVIDGE, J.L and BEYERLEIN, S.W GRI Report No 93/D181, Technical Reference Document for 2nd Edition of AGA Report No Reprinted March 1995 Gas Research Institute, Chicago, Illinois [15] STARLING, K.E and SAVIDGE, J.L Compressibility factors of natural gas and other related hydrocarbon gases American Gas Association, Transmission Measurement Committee Report No and American Petroleum Institute, MPMS chapter 14.2, second edition [16] ZEDAN, H.F and TEYSSANDIER, R.G The effect of recesses on the discharge coefficient of a flange tapped orifice plate, ASME Symposium on Mass Flow Measurement, 1984 1) ISO/IEC Guide 98-3 will be published as a reissue of the Guide to the Expression of Uncertainty in Measurement (GUM),1995 68 Copyright International Organization for Standardization Provided by IHS under license with ISO No reproduction or networking permitted without license from IHS © ISO 2008 – All rights reserved Not for Resale `,,```,,,,````-`-`,,`,,`,`,,` - Bibliography `,,```,,,,````-`-`,,`,,`,`,,` - Copyright International Organization for Standardization Provided by IHS under license with ISO No reproduction or networking permitted without license from IHS Not for Resale ISO/TR 9464:2008(E) ICS 17.120.10 Price based on 68 pages `,,```,,,,````-`-`,,`,,`,`,,` - © ISO 2008 – Allforrights reserved Copyright International Organization Standardization Provided by IHS under license with ISO No reproduction or networking permitted without license from IHS Not for Resale