EN ISO 5167-2:2003

SLOVENSKI STANDARD
01-januar-2004
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SIST EN ISO 5167-1:1997
SIST EN ISO 5167-1:1997/A1:2001
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Measurement of fluid flow by means of pressure differential devices inserted in circular
cross-section conduits running full - Part 2: Orifice plates (ISO 5167-2:2003)
Durchflussmessung von Fluiden mit Drosselgeräten in voll durchströmten Leitungen mit
Kreisquerschnitt - Teil 2: Blenden (ISO 5167-2:2003)
Mesure de débit des fluides au moyen d'appareils déprimogenes insérés dans des
conduites en charge de section circulaire - Partie 2: Diaphragmes (ISO 5167-2:2003)
Ta slovenski standard je istoveten z: EN ISO 5167-2:2003
ICS:
17.120.10 Pretok v zaprtih vodih Flow in closed conduits
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN STANDARD
EN ISO 5167-2
NORME EUROPÉENNE
EUROPÄISCHE NORM
March 2003
ICS 17.120.10 Together with EN ISO 5167-1:2003,
EN ISO 5167-3:2003 and EN ISO 5167-4:2003,
supersedes EN ISO 5167-1:1995
English version
Measurement of fluid flow by means of pressure differential
devices inserted in circular cross-section conduits running full -
Part 2: Orifice plates (ISO 5167-2:2003)
Mesure de débit des fluides au moyen d'appareils Durchflussmessung von Fluiden mit Drosselgeräten in voll
déprimogènes insérés dans des conduites en charge de durchströmten Leitungen mit Kreisquerschnitt - Teil 2:
section circulaire - Partie 2: Diaphragmes (ISO 5167- Blenden (ISO 5167-2:2003)
2:2003)
This European Standard was approved by CEN on 20 February 2003.
CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European
Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such national
standards may be obtained on application to the Management Centre or to any CEN member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by translation
under the responsibility of a CEN member into its own language and notified to the Management Centre has the same status as the official
versions.
CEN members are the national standards bodies of Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece,
Hungary, Iceland, Ireland, Italy, Luxembourg, Malta, Netherlands, Norway, Portugal, Slovak Republic, Spain, Sweden, Switzerland and
United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
Management Centre: rue de Stassart, 36  B-1050 Brussels
© 2003 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 5167-2:2003 E
worldwide for CEN national Members.

CORRECTED  2003-09-03
Foreword
This document (EN ISO 5167-2:2003) has been prepared by Technical Committee ISO/TC 30
"Measurement of fluid flow in closed conduits" in collaboration with CMC.
This European Standard shall be given the status of a national standard, either by publication of an
identical text or by endorsement, at the latest by September 2003, and conflicting national
standards shall be withdrawn at the latest by September 2003.
This document, together with EN ISO 5167-1:2003, EN ISO 5167-3:2003 and EN ISO 5167-4:2003,
supersedes EN ISO 5167-1:1995.
According to the CEN/CENELEC Internal Regulations, the national standards organizations of the
following countries are bound to implement this European Standard: Austria, Belgium, Czech
Republic, Denmark, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy,
Luxembourg, Malta, Netherlands, Norway, Portugal, Slovakia, Spain, Sweden, Switzerland and the
United Kingdom.
Endorsement notice
The text of ISO 5167-2:2003 has been approved by CEN as EN ISO 5167-2:2003 without any
modifications.
NOTE Normative references to International Standards are listed in Annex ZA (normative).
Annex ZA
(normative)
Normative references to international publications
with their relevant European publications
This European Standard incorporates by dated or undated reference, provisions from other
publications. These normative references are cited at the appropriate places in the text and the
publications are listed hereafter. For dated references, subsequent amendments to or revisions of any
of these publications apply to this European Standard only when incorporated in it by amendment or
revision. For undated references the latest edition of the publication referred to applies (including
amendments).
NOTE Where an International Publication has been modified by common modifications, indicated by
(mod.), the relevant EN/HD applies.
Publication Year Title EN Year
ISO 4006 1991 Measurement of fluid flow in closed EN 24006 1993
conduits - Vocabulary and symbols
ISO 5167-1 1991 Measurement of fluid flow by means of EN ISO 5167-1 1995
pressure differential devices - Part 1:
Orifice plates, nozzles and Venturi
tubes inserted in circular cross-section
conduits running full
INTERNATIONAL ISO
STANDARD 5167-2
First edition
2003-03-01
Measurement of fluid flow by means of
pressure differential devices inserted in
circular-cross section conduits running
full —
Part 2:
Orifice plates
Mesure de débit des fluides au moyen d'appareils déprimogènes
insérés dans des conduites en charge de section circulaire —
Partie 2: Diaphragmes
Reference number
ISO 5167-2:2003(E)
©
ISO 2003
ISO 5167-2:2003(E)
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ii © ISO 2003 — All rights reserved

ISO 5167-2:2003(E)
Contents Page
Foreword. iv
Introduction . v
1 Scope. 1
2 Normative references . 1
3 Terms, definitions and symbols . 1
4 Principles of the method of measurement and computation. 2
5 Orifice plates . 2
5.1 Description. 2
5.2 Pressure tappings. 6
5.3 Coefficients and corresponding uncertainties of orifice plates. 10
5.4 Pressure loss, ∆ϖ.13
6 Installation requirements . 15
6.1 General. 15
6.2 Minimum upstream and downstream straight lengths for installation between various
fittings and the orifice plate . 15
6.3 Flow conditioners . 20
6.4 Circularity and cylindricality of the pipe. 26
6.5 Location of orifice plate and carrier rings. 27
6.6 Method of fixing and gaskets . 28
Annex A (informative) Tables of discharge coefficients and expansibility [expansion] factors. 29
Annex B (informative) Flow conditioners. 41
Bibliography . 46

ISO 5167-2:2003(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 2.
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.
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 5167-2 was prepared by Technical Committee ISO/TC 30, Measurement of fluid flow in closed conduits,
Subcommittee SC 2, Pressure differential devices.
This first edition of ISO 5167-2, together with the second edition of ISO 5167-1 and the first editions of
ISO 5167-3 and ISO 5167-4, cancels and replaces the first edition of ISO 5167-1:1991, which has been
technically revised, and ISO 5167-1:1991/Amd.1:1998.
ISO 5167 consists of the following parts, under the general title Measurement of fluid flow by means of
pressure differential devices inserted in circular-cross section conduits running full :
 Part 1: General principles and requirements
 Part 2: Orifice plates
 Part 3: Nozzles and Venturi nozzles
 Part 4:Venturi tubes
iv © ISO 2003 — All rights reserved

ISO 5167-2:2003(E)
Introduction
ISO 5167, consisting of four parts, covers the geometry and method of use (installation and operating
conditions) of orifice plates, nozzles and Venturi tubes when they are inserted in a conduit running full to
determine the flowrate of the fluid flowing in the conduit. It also gives necessary information for calculating the
flowrate and its associated uncertainty.
ISO 5167 (all parts) is applicable only to pressure differential devices in which the flow remains subsonic
throughout the measuring section and where the fluid can be considered as single-phase, but is not applicable
to the measurement of pulsating flow. Furthermore, each of these devices can only be used within specified
limits of pipe size and Reynolds number.
ISO 5167 (all parts) deals with devices for which direct calibration experiments have been made, sufficient in
number, spread and quality to enable coherent systems of application to be based on their results and
coefficients to be given with certain predictable limits of uncertainty.
The devices introduced into the pipe are called “primary devices”. The term primary device also includes the
pressure tappings. All other instruments or devices required for the measurement are known as “secondary
1)
devices”. ISO 5167 (all parts) covers primary devices; secondary devices will be mentioned only occasionally.
ISO 5167 consists of the following four parts.
a) ISO 5167-1 gives general terms and definitions, symbols, principles and requirements as well as methods
of measurement and uncertainty that are to be used in
...