EN ISO 5167-3:2022
(Main)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 5167-3:2022)
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 5167-3:2022)
This document specifies the geometry and method of use (installation and operating conditions) of nozzles and Venturi nozzles when they are inserted in a conduit running full to determine the flowrate of the fluid flowing in the conduit.
This document also provides background information for calculating the flowrate and is applicable in conjunction with the requirements given in ISO 5167‑1.
This document is applicable to nozzles and Venturi nozzles in which the flow remains subsonic throughout the measuring section and where the fluid can be considered as single-phase. In addition, each of the devices can only be used within specified limits of pipe size and Reynolds number. It is not applicable to the measurement of pulsating flow. It does not cover the use of nozzles and Venturi nozzles in pipe sizes less than 50 mm or more than 630 mm, or where the pipe Reynolds numbers are below 10 000.
This document deals with
a) three types of standard nozzles:
1) ISA 1932[1] nozzle;
2) the long radius nozzle[2];
3) the throat-tapped nozzle
b) the Venturi nozzle.
The three types of standard nozzle are fundamentally different and are described separately in this document. The Venturi nozzle has the same upstream face as the ISA 1932 nozzle, but has a divergent section and, therefore, a different location for the downstream pressure tappings, and is described separately. This design has a lower pressure loss than a similar nozzle. For all of these nozzles and for the Venturi nozzle 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.
[1] ISA is the abbreviation for the International Federation of the National Standardizing Associations, which was superseded by ISO in 1946.
[2] The long radius nozzle differs from the ISA 1932 nozzle in shape and in the position of the pressure tappings.
Durchflussmessung von Fluiden mit Drosselgeräten in voll durchströmten Leitungen mit Kreisquerschnitt - Teil 3: Düsen und Venturidüsen (ISO 5167-3:2022)
Dieses Dokument legt die geometrischen Formen und Maße sowie die Anwendung (Einbau- und Betriebsbedingungen) von Düsen und Venturidüsen, die in einer voll durchströmten Rohrleitung zur Bestimmung des Durchflusses eines Fluids eingebaut sind, fest.
Dieses Dokument enthält grundlegende Informationen für die Durchflussberechnung und ist gemeinsam mit den in ISO 5167 1 festgelegten Anforderungen anzuwenden.
Dieses Dokument ist anzuwenden für Düsen und Venturidüsen, in denen die Strömung im gesamten Messquerschnitt im Unterschallbereich liegt und wo das Fluid als einphasig betrachtet werden kann. Weiterhin kann das betreffende Gerät nur innerhalb festgelegter Grenzen für Rohrdurchmesser und Reynolds-Zahl verwendet werden. Dieses Dokument ist nicht anzuwenden für Messungen bei pulsierenden Strömungen sowie für die Verwendung von Düsen und Venturidüsen bei Rohrdurchmessern kleiner als 50 mm oder größer als 630 mm oder für auf das Rohr bezogene Reynolds-Zahlen unter 10 000.
Dieses Dokument behandelt:
a) drei Arten von Norm-Düsen:
1) ISA-1932-Düsen ;
2) die Langradius-Düse ;
3) Düse mit Entnahmebohrung am Halsteil;
b) die Venturidüse.
Die drei Arten von Norm-Düsen sind grundsätzlich verschieden und sind in diesem Dokument getrennt behandelt. Die Venturidüse hat die gleiche Stirnseite auf der Einlaufseite wie die ISA-1932-Düse, aber ein divergierendes Teil (Diffusor) und deswegen eine andere Anordnung der Druckentnahmen auf der Auslaufseite und wird deshalb getrennt beschrieben. Diese Ausführung hat einen geringeren Druckverlust als eine gleichartige Düse. Für alle Düsen und für die Venturidüse wurden direkte Kalibrierungen, ausreichend in Anzahl, Spreizung und Qualität, durchgeführt, sodass die Ergebnisse der Kalibrierungen auf ähnliche Anordnungen übertragbar sind und die Kalibrierkoeffizienten innerhalb bestimmter Grenzen der Messunsicherheit angegeben werden können.
Mesurage du débit des fluides au moyen d'appareils déprimogènes insérés dans des conduites en charge de section circulaire - Partie 3: Tuyères et Venturi-tuyères (ISO 5167-3:2022)
Le présent document spécifie la géométrie et le mode d'emploi (conditions d'installation et d'utilisation) de tuyères et de Venturi-tuyères insérés dans une conduite en charge dans le but de déterminer le débit du fluide s'écoulant dans cette conduite.
Le présent document fournit également des informations de fond nécessaires au calcul de ce débit, et il convient de l'utiliser conjointement avec les exigences stipulées dans l’ISO 5167‑1.
Le présent document est applicable aux tuyères et aux Venturi-tuyères dans lesquels l'écoulement reste subsonique dans tout le tronçon de mesurage et dans lesquels un fluide peut être considéré comme monophasique. De plus, chacun de ces appareils ne peut être utilisé que dans des limites spécifiées de diamètre de conduite et de nombre de Reynolds. Il n'est pas applicable au mesurage d'un écoulement pulsé. Il ne couvre pas l'utilisation de tuyères et de Venturi-tuyères dans des conduites de diamètre inférieur à 50 mm ou supérieur à 630 mm, ni les cas où les nombres de Reynolds rapportés à la tuyauterie sont inférieurs à 10 000.
Le présent document traite
a) de trois types de tuyères normalisées:
la tuyère ISA 1932[1];
la tuyère à long rayon[2];
la tuyère avec prises de pression au col;
b) du Venturi-tuyère.
Les trois types de tuyères normalisées sont fondamentalement différents et sont décrits séparément dans le présent document. Le Venturi-tuyère a la même face amont que la tuyère ISA 1932, mais, étant donné qu'il comporte un divergent et, par conséquent, un emplacement différent pour les prises de pression aval, il est décrit séparément. Ce modèle présente une perte de pression plus basse qu’une tuyère similaire. Pour toutes ces tuyères et pour le Venturi-tuyère, des étalonnages directs ont été réalisés, en nombre suffisant, sur une gamme suffisante et avec une qualité suffisante pour permettre à des systèmes d'application cohérents de se baser sur leurs résultats et coefficients dans certaines limites prévisibles d'incertitude.
[1] ISA est le sigle de la Fédération internationale des associations nationales de normalisation, organisme remplacé par l’ISO en 1946.
[2] La tuyère à long rayon se distingue de la tuyère ISA 1932 par sa forme et par la position des prises de pression.
Merjenje pretoka fluida na osnovi tlačne razlike, povzročene z napravo, vstavljeno v polno zapolnjen vod s krožnim prerezom - 3. del: Šobe in Venturijeve šobe (ISO 5167-3:2022)
Ta dokument določa geometrijo in metodo uporabe (namestitev in pogoje delovanja) šob in Venturijevih šob, kadar so vstavljene v polno zapolnjen vod za ugotavljanje hitrosti pretoka fluida skozi vod.
Prav tako podaja dodatne informacije za izračunavanje hitrosti pretoka in se uporablja skupaj z zahtevami iz standarda ISO 5167‑1.
Dokument se uporablja za šobe in Venturijeve šobe, ki v predelu merjenja ohranjajo podzvočen pretok in pri katerih se lahko fluid obravnava kot enofazen. Vsako od teh naprav je mogoče uporabljati samo v okviru določenih omejitev glede velikosti cevi in Reynoldsovega števila. Ne uporablja se za merjenje utripajočega pretoka. Ne obravnava uporabe šob in Venturijevih šob v ceveh z velikostjo manj kot 50 mm ali več kot 630 mm, ali pri katerih so Reynoldsova števila za cevi nižja od 10.000.
Ta dokument obravnava:
a) tri vrste standardnih šob:
šoba ISA 1932[1];
šoba z dolgim polmerom[2];
šoba z zoženim grlom;
b) Venturijevo šobo.
Naštete vrste standardnih šob se bistveno razlikujejo in so v tem dokumentu opisane ločeno. Venturijeva šoba ima enako gornjo ploskev kot šoba ISA 1932, vendar ima divergenten odsek ter zato drugačno lokacijo za tlačne odcepe v smeri toka in je opisana ločeno. Ta zasnova ima nižjo izgubo tlaka kot katera koli podobna šoba. Za vse te šobe in za Venturijevo šobo so bili opravljeni poskusi neposrednega umerjanja v zadostnem številu, razpršenosti in kakovosti, da so omogočili skladne sisteme uporabe, ki temeljijo na njihovih rezultatih in podajo koeficiente z določenimi predvidljivimi mejami negotovosti.
[1] ISA je okrajšava za Mednarodno zvezo nacionalnih združenj za standardizacijo, ki jo je leta 1946 nadomestila organizacija ISO.
[2] Šoba z dolgim polmerom se razlikuje od šobe ISA 1932 po obliki in položaju tlačnih odcepov.
General Information
Relations
Standards Content (Sample)
SLOVENSKI STANDARD
01-januar-2023
Nadomešča:
SIST EN ISO 5167-3:2020
Merjenje pretoka fluida na osnovi tlačne razlike, povzročene z napravo, vstavljeno
v polno zapolnjen vod s krožnim prerezom - 3. del: Šobe in Venturijeve šobe (ISO
5167-3:2022)
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 5167-
3:2022)
Durchflussmessung von Fluiden mit Drosselgeräten in voll durchströmten Leitungen mit
Kreisquerschnitt - Teil 3: Düsen und Venturidüsen (ISO 5167-3:2022)
Mesurage du débit des fluides au moyen d'appareils déprimogènes insérés dans des
conduites en charge de section circulaire - Partie 3: Tuyères et Venturi-tuyères (ISO
5167-3:2022)
Ta slovenski standard je istoveten z: EN ISO 5167-3:2022
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.
EN ISO 5167-3
EUROPEAN STANDARD
NORME EUROPÉENNE
November 2022
EUROPÄISCHE NORM
ICS 17.120.10 Supersedes EN ISO 5167-3:2020
English Version
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 5167-3:2022)
Mesurage du débit des fluides au moyen d'appareils Durchflussmessung von Fluiden mit Drosselgeräten in
déprimogènes insérés dans des conduites en charge de voll durchströmten Leitungen mit Kreisquerschnitt -
section circulaire - Partie 3: Tuyères et Venturi-tuyères Teil 3: Düsen und Venturidüsen (ISO 5167-3:2022)
(ISO 5167-3:2022)
This European Standard was approved by CEN on 22 October 2022.
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 CEN-CENELEC 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 CEN-CENELEC Management
Centre has the same status as the official versions.
CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway,
Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Türkiye and
United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2022 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 5167-3:2022 E
worldwide for CEN national Members.
Contents Page
European foreword . 3
European foreword
This document (EN ISO 5167-3:2022) has been prepared by Technical Committee ISO/TC 30
"Measurement of fluid flow in closed conduits" in collaboration with CCMC.
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 May 2023, and conflicting national standards shall be
withdrawn at the latest by May 2023.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN shall not be held responsible for identifying any or all such patent rights.
This document supersedes EN ISO 5167-3:2020.
Any feedback and questions on this document should be directed to the users’ national standards
body/national committee. A complete listing of these bodies can be found on the CEN website.
According to the CEN-CENELEC Internal Regulations, the national standards organizations of the
following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria,
Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland,
Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Republic of
North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Türkiye and the
United Kingdom.
Endorsement notice
The text of ISO 5167-3:2022 has been approved by CEN as EN ISO 5167-3:2022 without any
modification.
INTERNATIONAL ISO
STANDARD 5167-3
Third edition
2022-10
Measurement of fluid flow by means of
pressure differential devices inserted
in circular cross-section conduits
running full —
Part 3:
Nozzles and Venturi nozzles
Mesurage du débit des fluides au moyen d'appareils déprimogènes
insérés dans des conduites en charge de section circulaire —
Partie 3: Tuyères et Venturi-tuyères
Reference number
ISO 5167-3:2022(E)
ISO 5167-3:2022(E)
© ISO 2022
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on
the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below
or ISO’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: +41 22 749 01 11
Email: copyright@iso.org
Website: www.iso.org
Published in Switzerland
ii
ISO 5167-3:2022(E)
Contents Page
Foreword .v
Introduction . vi
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 2
4 Principles of the method of measurement and computation . 2
5 Nozzles and Venturi nozzles . 3
5.1 ISA 1932 nozzle . 3
5.1.1 General shape . 3
5.1.2 Nozzle profile . 3
5.1.3 Downstream face . 5
5.1.4 Material and manufacture . 5
5.1.5 Pressure tappings . 5
5.1.6 Coefficients of ISA 1932 nozzles . 7
5.1.7 Uncertainties . 8
5.1.8 Pressure loss, Δϖ . 8
5.2 Long radius nozzles . 9
5.2.1 General . 9
5.2.2 Profile of high-ratio nozzle . 9
5.2.3 Profile of low-ratio nozzle . 11
5.2.4 Material and manufacture .12
5.2.5 Pressure tappings .12
5.2.6 Coefficients of long radius nozzles .12
5.2.7 Uncertainties .13
5.2.8 Pressure loss, Δϖ .13
5.3 Throat-tapped nozzles . 13
5.3.1 General .13
5.3.2 Profile of throat-tapped nozzle. 14
5.3.3 Material and manufacturing . 15
5.3.4 Pressure tappings . 15
5.3.5 Coefficients . 16
5.3.6 Uncertainties . 16
5.3.7 Calibration and extrapolation . 17
5.3.8 Pressure Loss . 17
5.4 Venturi nozzles . 18
5.4.1 General shape . 18
5.4.2 Material and manufacture . 20
5.4.3 Pressure tappings . 20
5.4.4 Coefficients . 21
5.4.5 Uncertainties .22
5.4.6 Pressure loss .22
6 Installation requirements .23
6.1 General .23
6.2 Minimum upstream and downstream straight lengths for installation between
various fittings and the primary device . 23
6.3 Flow conditioners . 29
6.4 Circularity and cylindricality of the pipe .29
6.5 Location of primary device and carrier rings .30
6.6 Method of fixing and gaskets . 31
7 Flow calibration of nozzles .31
7.1 General . 31
7.2 Test facility . 32
iii
ISO 5167-3:2022(E)
7.3 Meter installation . . 32
7.4 Design of the test programme . 32
7.5 Reporting the calibration results . 32
7.6 Uncertainty analysis of the calibration . 32
7.6.1 General . 32
7.6.2 Uncertainty of the test facility . 33
7.6.3 Uncertainty of the nozzle . 33
Annex A (informative) Tables of discharge coefficients and expansibility [expansion]
factors .34
Annex B (informative) Akashi type (Mitsubishi type) flow conditioner .41
Bibliography .42
iv
ISO 5167-3:2022(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.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the
different types of ISO documents should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www.iso.org/directives).
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. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received (see www.iso.org/patents).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and
expressions related to conformity assessment, as well as information about ISO's adherence to
the World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT) see
www.iso.org/iso/foreword.html.
This document was prepared by Technical Committee ISO/TC 30, Measurement of fluid flow in closed
conduits, Subcommittee SC 2, Pressure differential devices, in collaboration with the European Committee
for Standardization (CEN) Technical Committee CEN/SS F05, Measuring instruments, in accordance with
the Agreement on technical cooperation between ISO and CEN (Vienna Agreement).
This third edition cancels and replaces the second edition (ISO 5167-3:2020), of which it constitutes a
minor revision. The main changes are as follows:.
— harmonization with ISO/IEC Guide 98-3;
— minor changes to give harmonization with the other parts of ISO 5167.
A list of all parts in the ISO 5167 series can be found on the ISO website.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www.iso.org/members.html.
v
ISO 5167-3:2022(E)
Introduction
ISO 5167, consisting of six parts, covers the geometry and method of use (installation and operating
conditions) of orifice plates, nozzles, Venturi tubes, cone meters and wedge meters 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. ISO 5167 also
provides methdology for bespoke calibration of differential pressure meters.
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 to facilitate the instrument readings
are known as secondary devices, and the flow computer that receives these readings and performs
the algorithms is known as a tertiary device. ISO 5167 (all parts) covers primary devices; secondary
devices (ISO 2186) and tertiary devices will be mentioned only occasionally.
Aspects of safety are not dealt within ISO 5167-1 to ISO 5167-6. It is the responsibility of the user to
ensure that the system meets applicable safety regulations.
vi
INTERNATIONAL STANDARD ISO 5167-3:2022(E)
Measurement of fluid flow by means of pressure
differential devices inserted in circular cross-section
conduits running full —
Part 3:
Nozzles and Venturi nozzles
1 Scope
This document specifies the geometry and method of use (installation and operating conditions) of
nozzles and Venturi nozzles when they are inserted in a conduit running full to determine the flowrate
of the fluid flowing in the conduit.
This document also provides background information for calculating the flowrate and is applicable in
conjunction with the requirements given in ISO 5167-1.
This document is applicable to nozzles and Venturi nozzles in which the flow remains subsonic
throughout the measuring section and where the fluid can be considered as single-phase. In addition,
each of the devices can only be used within specified limits of pipe size and Reynolds number. It is
not applicable to the measurement of pulsating flow. It does not cover the use of nozzles and Venturi
nozzles in pipe sizes less than 50 mm or more than 630 mm, or where the pipe Reynolds numbers are
below 10 000.
This document deals with
a) three types of standard nozzles:
1)
1) ISA 1932 nozzle;
2)
2) the long radius nozzle ;
3) the throat-tapped nozzle
b) the Venturi nozzle.
The three types of standard nozzle are fundamentally different and are described separately in this
document. The Venturi nozzle has the same upstream face as the ISA 1932 nozzle, but has a divergent
section and, therefore, a different location for the downstream pressure tappings, and is described
separately. This design has a lower pressure loss than a similar nozzle. For all of these nozzles and for
the Venturi nozzle 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.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements 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.
1) ISA is the abbreviation for the International Federation of the National Standardizing Associations, which was
superseded by ISO in 1946.
2) The long radius nozzle differs from the ISA 1932 nozzle in shape and in the position of the pressure tappings.
ISO 5167-3:2022(E)
ISO 4006, Measurement of fluid flow in closed conduits — Vocabulary and symbols
ISO 5167-1, Measurement of fluid flow by means of pressure differential devices inserted in circular cross-
section conduits running full — Part 1: General principles and requirements
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 4006 and ISO 5167-1 apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at https:// www .electropedia .org/
4 Principles of the method of measurement and computation
The principle of the method of measurement is based on the installation of a nozzle or a Venturi nozzle
into a pipeline in which a fluid is running full. The installation of the primary device causes a static
pressure difference between the upstream side and the throat. The flowrate can be determined from
the measured value of this pressure difference and from the knowledge of the characteristics of the
flowing fluid as well as the circumstances under which the device is being used. It is assumed that the
device is geometrically similar to one on which calibration has been carried out and that the conditions
of use are the same, i.e. that it is in accordance with this document.
The mass flowrate can be determined by Formula (1):
C π
q = ερdp2Δ (1)
m 1
4 4
1−β
The uncertainty limits can be calculated using the procedure given in ISO 5167-1:2022, Clause 8.
Similarly, the value of the volume flowrate can be calculated by Formula (2) since
q
m
q = (2)
V
ρ
where
ρ is the fluid density at the temperature and pressure for which the volume is stated;
q is the volume flowrate.
V
Computation of the flowrate, which is a purely arithmetic process, is performed by replacing the
different items on the right-hand side of Formula (1) by their numerical values. Tables A.1 to A.5 are
given for convenience. Tables A.1, A.2 and A.4 give the values of C as a function of β. Table A.3 gives
the values of C as a function of Re . Table A.5 gives expansibility (expansion) factors, ε. They are not
d
intended for precise interpolation. Extrapolation is not permitted.
The discharge coefficient C may be dependent on Re or Re which is itself dependent on q and has to
D d m
be obtained by iteration. (See ISO 5167-1 for guidance regarding the choice of the iteration procedure
and initial estimates.)
The diameters d and D mentioned in Formula (1) are the values of the diameters at working conditions.
Measurements taken at any other conditions should be corrected for any possible expansion or
contraction of the primary device and the pipe due to the values of the temperature and pressure of the
fluid during the measurement.
ISO 5167-3:2022(E)
It is necessary to know the density and the viscosity of the fluid at working conditions. In the case
of a compressible fluid, it is also necessary to know the isentropic exponent of the fluid at working
conditions.
5 Nozzles and Venturi nozzles
5.1 ISA 1932 nozzle
5.1.1 General shape
The part of the nozzle inside the pipe is circular. The nozzle consists of a convergent section with a
rounded profile, and a cylindrical throat.
Figure 1 shows the cross-section of an ISA 1932 nozzle at a plane passing through the centreline of the
throat.
The letters in the following text refer to those shown on Figure 1.
5.1.2 Nozzle profile
5.1.2.1 The profile of the nozzle may be characterized by distinguishing:
— a flat inlet part A, perpendicular to the centreline;
— a convergent section defined by two arcs of circumference B and C;
— a cylindrical throat E;
— a recess F which is optional (it is required only if damage to the edge G is feared).
5.1.2.2 The flat inlet part A is limited by a circumference centred on the axis of revolution, with a
diameter of 1,5d, and by the inside circumference of the pipe, of diameter D.
When d = (2/3)D, the radial width of this flat part is zero.
When d is greater than (2/3)D, the upstream face of the nozzle does not include a flat inlet part within
the pipe. In this case, the nozzle is manufactured as if D were greater than 1,5d, and the inlet flat part
is then faced off so that the largest diameter of the convergent profile is just equal to D [see 5.1.2.7 and
Figure 1 b)].
5.1.2.3 The arc of circumference B is tangential to the flat inlet part A when d < (2/3)D while its
radius R is equal to 0,2d ± 0,02d for β < 0,5 and to 0,2d ± 0,006d for β ≥ 0,5. Its centre is at 0,2d from the
inlet plane and at 0,75d from the axial centreline.
5.1.2.4 The arc of circumference C is tangential to the arc of circumference B and to the throat E.
Its radius R is equal to d/3 ± 0,033d for β < 0,5 and to d/3 ± 0,01d for β ≥ 0,5. Its centre is at
d/2 + d/3 = (5/6)d from the axial centreline and as given by Formula (3), at
12+ 39
ad= =0,3041d (3)
n
from the flat inlet part A.
ISO 5167-3:2022(E)
a) d ≤ (2/3)D b) d > (2/3)D
Key
1 portion to be cut off
a
See 5.1.2.7.
b
Direction of flow.
Figure 1 — ISA 1932 nozzle
5.1.2.5 The throat E has a diameter d and a length b = 0,3d.
n
The value d of the diameter of the throat shall be taken as the mean of the measurements of at least four
diameters distributed in axial planes and at approximately equal angles to each other.
The throat shall be cylindrical. No diameter of any cross-section shall differ by more than 0,05 % from
the value of the mean diameter. This requirement is considered to be satisfied when the deviations in
the length of any of the measured diameters comply with the said requirement in respect of deviation
from the mean.
ISO 5167-3:2022(E)
5.1.2.6 The recess F has a diameter c equal to at least 1,06d and a length less than or equal to 0,03d.
n
The ratio of the depth (c − d)/2 of the recess to its axial length shall not be greater than 1,2.
n
The outlet edge G shall be sharp.
5.1.2.7 The total length of the nozzle, excluding the recess F, as a function of β is equal to
0,604 1d for 0,3 ≤ β ≤
and
07,,50 25 2
0,404 1+− −0,,522 5 d for <≤β 08.
2
β 3
β
5.1.2.8 The profile of the convergent inlet shall be checked by means of a template.
Two diameters of the convergent inlet in the same plane perpendicular to the axial centreline shall not
differ from each other by more than 0,1 % of their mean value.
5.1.2.9 The surface of the upstream face and the throat shall be such that they have a roughness
−4
criterion Ra ≤ 10 d.
5.1.3 Downstream face
5.1.3.1 The thickness, H shall not exceed 0,1D.
5.1.3.2 Apart from the condition given in 5.1.3.1, the profile and the surface finish of the downstream
face are not specified (see 5.1.1).
5.1.4 Material and manufacture
The ISA 1932 nozzle may be manufactured from any material and in any way, provided that it remains
in accordance with the foregoing description during flow measurement.
5.1.5 Pressure tappings
5.1.5.1 Corner pressure tappings shall be used upstream of the nozzle.
The upstream pressure tappings may be either single tappings or annular slots. Both types of tappings
may be located either in the pipe or its flanges or in carrier rings as shown in Figure 1.
The spacing between the centrelines of individual upstream tappings and face A is equal to half the
diameter or to half the width of the tappings themselves, so that the tapping holes break through the
wall flush with face A. The centreline of individual upstream tappings shall meet the centreline of the
primary device at an angle of as near 90° as possible.
The diameter δ of a single upstream tapping and the width a of annular slots are specified below. The
minimum diameter is determined in practice by the need to prevent accidental blockage and to give
satisfactory dynamic performance.
For clean fluids and vapours:
— for β ≤ 0,65: 0,005D ≤ a or δ ≤ 0,03D
— for β > 0,65: 0,01D ≤ a or δ ≤ 0,02D.
ISO 5167-3:2022(E)
For any value of β:
— for clean fluids: 1 mm ≤ a or δ ≤ 10 mm
— for vapours, in the case of annular chambers: 1 mm ≤ a ≤ 10 mm
— for vapours and for liquefied gases, in the case of single tappings: 4 mm ≤ δ ≤ 10 mm.
NOTE The requirements on size as a fraction of pipe diameter are based on geometrical similarity to the
original nozzle runs on which the discharge coefficient is based. For vapours and for liquefied gases, there are
pipe diameters for which it is not possible to manufacture a system using single tappings that is in accordance
with this document.
The annular slots usually break through the pipe over the entire perimeter, with no break in continuity.
If not, each annular chamber shall connect with the inside of the pipe by at least four openings, the axes
of which are at equal angles to one another and the individual opening area of which is at least 12 mm .
The internal diameter b of the carrier rings shall be greater than or equal to the diameter D of the pipe,
to ensure that they do not protrude into the pipe, but shall be less than or equal to 1,04D. Moreover, the
following condition shall be met:
bD− c 01,
××100≤ (4)
D D
01,,+23β
The length c of the upstream ring (see Figure 1) shall not be greater than 0,5D.
The thickness f of the slot shall be greater than or equal to twice the width a of the annular slot. The
area of the cross-section of the annular chamber, gh, shall be greater than or equal to half the total area
of the opening connecting this chamber to the inside of the pipe.
All surfaces of the ring which are in contact with the measured fluid shall be clean and shall have a well-
machined finish.
The pressure tappings connecting the annular chambers to the secondary devices are pipe-wall
tappings, circular at the point of break-through and with a diameter j between 4 mm and 10 mm.
The upstream and downstream carrier rings need not necessarily be symmetrical in relation to each
other, but they shall both conform to the preceding requirements.
The diameter of the pipe shall be measured as specified in 6.4.2, the carrier ring being regarded as part
of the primary device. This also applies to the distance requirement given in 6.4.4 so that s shall be
measured from the upstream edge of the recess formed by the carrier ring.
5.1.5.2 The downstream pressure tappings may either be corner tappings as described in 5.1.5.1 or
be as described in the remainder of this subclause.
The distance between the centre of the tapping and the upstream face of the nozzle shall be
— ≤0,15D for β ≤ 0,67;
— ≤0,20D for β > 0,67.
When installing the pressure tappings, due account shall be taken of the thickness of the gaskets and/
or sealing material.
The centreline of the tapping shall meet the pipe centreline at an angle as near to 90° as possible but in
every case within 3° of the perpendicular. At the point of break-through, the hole shall be circular. The
edges shall be flush with the internal surface of the pipe wall and as sharp as possible. To ensure the
elimination of all burrs or wire edges at the inner edge, rounding is permitted but shall be kept as small
as possible and, where it can be measured, its radius shall be less than one-tenth of the pressure-tapping
diameter. No irregularity shall appear inside the connecting hole, on the edges of the hole drilled in the
ISO 5167-3:2022(E)
pipe wall or on the pipe wall close to the pressure tapping. Conformity of the pressure tappings with
the requirements of this paragraph may be judged by visual inspection.
The diameter of pressure tappings shall be less than 0,13D and less than 13 mm.
No restriction is placed on the minimum diameter, which is determined in practice by the need
to prevent accidental blockage and to give satisfactory dynamic performance. The upstream and
downstream tappings shall have the same diameter.
The pressure tappings shall be circular and cylindrical over a length of at least 2,5 times the internal
diameter of the tapping, measured from the inner wall of the pipeline.
The centrelines of the pressure tappings may be located in any axial plane of the pipeline.
The axis of the upstream tapping and that of the downstream tapping may be located in different axial
planes.
5.1.6 Coefficients of ISA 1932 nozzles
5.1.6.1 Limits of use
This type of nozzle shall only be used in accordance with this document when
— 50 mm ≤ D ≤ 500 mm;
— 0,3 ≤ β ≤ 0,8;
and when Re is within the following limits:
D
4 7
— for 0,30 ≤ β < 0,44 7 × 10 ≤ Re ≤ 10 ;
D
4 7
— for 0,44 ≤ β ≤ 0,80 2 × 10 ≤ Re ≤ 10 .
D
In addition, the relative roughness of the pipe shall conform to the values given in Table 1.
Table 1 — Upper limits of relative roughness of the upstream pipe for ISA 1932 nozzles
β ≤0,35 0,36 0,38 0,40 0,42 0,44 0,46 0,48 0,50 0,60 0,70 0,77 0,80
10 Ra/D 8,0 5,9 4,3 3,4 2,8 2,4 2,1 1,9 1,8 1,4 1,3 1,2 1,2
NOTE Most of the data on which this table is based were probably collected in the range Re ≤ 10 ; at higher Reynolds
D
numbers more stringent limits on pipe roughness are probably required.
Most of the experiments on which the values of the discharge coefficient C given in this document are
−4
based were carried out in pipes with a relative roughness Ra/D ≤ 1,2 × 10 . Pipes with higher relative
roughness may be used if the roughness for a distance of at least 10D upstream of the nozzle is within
the limits given in Table 1. Information as to how to determine Ra is given in ISO 5167-1.
5.1.6.2 Discharge coefficient, C
The discharge coefficient, C, is given by Formula (5):
11, 5
41,,24 15
C =−0,,990 00 226 20ββ−−,,001 75 0 003 3β (5)
()
Re
D
Values of C as a function of β and Re are given for convenience in Table A.1. These values are not
D
intended for precise interpolation. Extrapolation is not permitted.
ISO 5167-3:2022(E)
5.1.6.3 Expansibility [expansion] factor, ε
The expansibility [expansion] factor, ε, is calculated by means of Formula (6):
κκ−1 /
24/κ ()
κτ 1−β 1−τ
ε = (6)
42/κ
κ −1 1−τ
1−βτ
Formula (6) is applicable only for values of β, D and Re as specified in 5.1.6.1. Test results for
D
determination of ε are only known for air, steam and natural gas. However, there is no known objection
to using the same formula for other gases and vapours for which the isentropic exponent is known.
However, Formula (6) is applicable only if p /p ≥ 0,75.
2 1
Values of the expansibility [expansion] factor for a range of isentropic exponents, pressure ratios
and diameter ratios are given for convenience in Table A.5. These values are not intended for precise
interpolation. Extrapolation is not permitted.
5.1.7 Uncertainties
5.1.7.1 Uncertainty of discharge coefficient, C
'
When β, D, Re and Ra/D are assumed to be known without error, U , the relative expanded uncertainty
D C
of the value of C at k = 2 (approximately 95 % confidence level), is equal to
— 0,8 % for β ≤ 0,6;
— (2β − 0,4) % for β > 0,6.
5.1.7.2 Uncertainty of expansibility [expansion] factor ε
′
U , the relative expanded uncertainty of the value of ε at k = 2 (approximately 95 % confidence level), is
ε
equal to
Δp
2 %
p
5.1.8 Pressure loss, Δϖ
The pressure loss, Δϖ, for the ISA 1932 nozzle is approximately related to the differential pressure Δp
by Formula (7)
42 2
11−−ββCC−
()
ΔΔϖ = p (7)
42 2
11−−ββCC+
()
This pressure loss is the difference in static pressure between the pressure measured at the wall
on the upstream side of the primary device at a section where the influence of the approach impact
pressure adjacent to the device is still negligible (approximately D upstream of the primary device)
and that measured on the downstream side of the primary device where the static pressure recovery
by expansion of the jet may be considered as just completed (approximately 6D downstream of the
primary device).
ISO 5167-3:2022(E)
The pressure loss coefficient, K, for the ISA 1932 nozzle is
11−−β C
()
K = −1 (8)
2
Cβ
where K is defined by Formula (9):
Δϖ
K = (9)
ρ U
5.2 Long radius nozzles
5.2.1 General
There are two types of long radius nozzles, which are called
— high-ratio nozzles (0,25 ≤ β ≤ 0,8);
— low-ratio nozzles (0,20 ≤ β ≤ 0,5).
For β values between 0,25 and 0,5 either design may be used.
Figure 2 illustrates the geometric shapes of long radius nozzles, showing cross-sections passing through
the throat centrelines.
The reference letters used in the text refer to those shown on Figure 2.
Both types of nozzles consist of a convergent inlet, whose shape is a quarter ellipse, and a cylindrical
throat.
That part of the nozzle which is inside the pipe shall be circular, with the possible exception of the holes
of the pressure tappings.
5.2.2 Profile of high-ratio nozzle
5.2.2.1 The inner face can be characterized by
— a convergent section A;
— a cylindrical throat B;
— a plain end C.
5.2.2.2 The convergent section A has the shape of a quarter ellipse.
The centre of the ellipse is at a distance D/2 from the axial centreline. The major centreline of the ellipse
is parallel to the axial centreline. The value of half the major axis is D/2. The value of half the minor axis
is (D − d)/2.
The profile of the convergent section shall be checked by means of a template. Two diameters of the
convergent section in the same plane perpendicular to the centreline shall not differ from each other by
more than 0,1 % of their mean value.
5.2.2.3 The throat B has a diameter d and a length 0,6d.
The value d of the diameter of the throat shall be taken as the mean of the measurements of at least four
diameters distributed in axial planes and at approximately equal angles to each other.
ISO 5167-3:2022(E)
The th
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