Measurement of fluid flow by means of pressure differential devices inserted in circular cross-section conduits running full - Part 5: Cone meters (ISO 5167-5:2016)

ISO 5167-5:2016 specifies the geometry and method of use (installation and operating conditions) of cone meters when they are inserted in a conduit running full to determine the flow rate of the fluid flowing in the conduit.
As the uncertainty of an uncalibrated cone meter might be too high for a particular application, it might be deemed essential to calibrate the flow meter in accordance with Clause 7.
ISO 5167-5:2016 also provides background information for calculating the flow rate and is applicable in conjunction with the requirements given in ISO 5167‑1.
ISO 5167-5:2016 is applicable only to cone meters in which the flow remains subsonic throughout the measuring section and where the fluid can be considered as single-phase. Uncalibrated cone meters can only be used within specified limits of pipe size, roughness, β, and Reynolds number. This part of ISO 5167 is not applicable to the measurement of pulsating flow. It does not cover the use of uncalibrated cone meters in pipes sized less than 50 mm or more than 500 mm, or where the pipe Reynolds numbers are below 8 × 104 or greater than 1,2 × 107.
A cone meter is a primary device which consists of a cone-shaped restriction held concentrically in the centre of the pipe with the nose of the cone upstream. The design of cone meter defined in this part of ISO 5167 has one or more upstream pressure tappings in the wall, and a downstream pressure tapping positioned in the back face of the cone with the connection to a differential pressure transmitter being a hole through the cone to the support bar, and then up through the support bar.
Alternative designs of cone meters are available; however, at the time of writing, there is insufficient data to fully characterize these devices, and therefore, these meters shall be calibrated in accordance with Clause 7.

Durchflussmessung von Fluiden mit Drosselgeräten in voll durchströmten Leitungen mit Kreisquerschnitt - Teil 5: Konus-Durchflussmesser (ISO 5167-5:2016)

Mesure de débit des fluides au moyen d'appareils déprimogènes insérés dans des conduites en charge de section circulaire - Partie 5: Cônes de mesure (ISO 5167-5:2016)

ISO 5167-5:2016 spécifie la géométrie et le mode d'emploi (conditions d'installation et d'utilisation) de cônes de mesure insérés dans une conduite en charge dans le but de déterminer le débit du fluide s'écoulant dans cette conduite.
Étant donné que l'incertitude d'un cône de mesure non étalonné risque d'être trop élevée pour une application particulière, l'étalonnage du débitmètre conformément à l'Article 7 pourrait être considéré comme essentiel.
ISO 5167-5:2016 fournit également des informations de fond nécessaires au calcul du débit et elle est applicable conjointement avec les exigences stipulées dans l'ISO 5167‑1.
ISO 5167-5:2016 est applicable uniquement aux cônes de mesure pour lesquels l'écoulement reste subsonique dans tout le tronçon de mesurage et où le fluide peut être considéré comme monophasique. Les cônes de mesure non étalonnés ne peuvent être utilisés que dans des limites spécifiées de diamètre de conduite, de rugosité, de valeur de β et de nombre de Reynolds. La présente partie de l'ISO 5167 n'est pas applicable au mesurage d'un écoulement pulsé. Elle ne couvre pas l'utilisation de cônes de mesure non étalonnés dans des conduites de diamètre inférieur à 50 mm ou supérieur à 500 mm, ni les cas où les nombres de Reynolds rapportés à la tuyauterie sont inférieurs à 8 × 104 ou supérieurs à 1,2 × 107.
Un cône de mesure est un élément primaire composé d'une restriction conique maintenue de manière concentrique au centre de la conduite, le nez du cône étant situé en amont. La conception d'un cône de mesure définie dans la présente partie de l'ISO 5167 comprend une ou plusieurs prises de pression amont dans la paroi et une prise de pression aval positionnée dans la face arrière du cône. Le raccordement à un transmetteur de pression différentielle se fait par un trou dans le cône menant à la barre de support, puis vers le haut à travers la barre de support.
D'autres conceptions de cônes de mesure sont possibles; cependant, au moment de la rédaction de cette norme les données permettant de caractériser complètement ces appareils étaient insuffisantes et ces derniers doivent donc être étalonnés conformément à l'Article 7.

Merjenje pretoka fluida na osnovi tlačne razlike, povzročene z napravo, vstavljeno v polno zapolnjen vod s krožnim prerezom - 5. del: Stožčasta merila (ISO 5167-5:2016)

Ta del standarda ISO 5167 določa geometrijo in metodo uporabe (namestitev in pogoji delovanja) stožčastih meril, kadar so ta vstavljena v polno zapolnjen vod za ugotavljanje stopnje pretoka fluida skozi vod.
Ker je lahko stopnja negotovosti neumerjenega stožčastega merila previsoka za ustrezni način uporabe, se lahko umerjanje merilnika pretoka obravnava kot bistveno v skladu s točko 7.
Ta del standarda ISO 5167 podaja tudi dodatne informacije za izračunavanje stopnje pretoka in se
uporablja skupaj z zahtevami, podanimi v standardu ISO 5167-1.
Ta del standarda ISO 5167 se uporablja samo za stožčasta merila, ki v predelu merjenja ohranjajo podzvočen pretok in pri katerih se lahko fluid obravnava kot enofazen. Neumerjena stožčasta merila se lahko uporabljajo samo v okviru določenih omejitev glede velikosti cevi, grobosti, koeficienta β in Reynoldsovega števila. Ta del standarda ISO 5167 se ne uporablja za merjenje utripajočega pretoka. Ne obravnava uporabe neumerjenih stožčastih meril v ceveh z velikostjo pod 50 mm ali nad 500 mm, ali pri katerih so Reynoldsova števila za cevi manj kot 8 × 104 ali več kot 1,2 × 107.
Stožčasto merilo je osnovna naprava, sestavljena iz stožčastega omejevalnika, ki je postavljen koncentrično v središču cevi, pri čemer je konica stožca obrnjena proti toku. Zasnova stožčastega merila, določenega v tem delu standarda ISO 5167, vključuje vsaj en tlačni odcep v steni (proti toku) in en tlačni odcep (v smeri toka) na zadnji strani stožca s povezavo do prenosnika diferencialnega tlaka v obliki odprtine skozi stožec do opornika in skozi opornik. Na voljo so tudi druge zasnove stožčastih meril, vendar v času pisanja ni zadostnih podatkov za ustrezno označevanje teh naprav. Zaradi tega je treba tovrstna merila umeriti v skladu s točko 7.

General Information

Status
Published
Publication Date
29-Mar-2016
Current Stage
6060 - Definitive text made available (DAV) - Publishing
Due Date
30-Mar-2016
Completion Date
30-Mar-2016

RELATIONS

Buy Standard

Standard
EN ISO 5167-5:2016
English language
23 pages
sale 10% off
Preview
sale 10% off
Preview
e-Library read for
1 day

Standards Content (sample)

SLOVENSKI STANDARD
SIST EN ISO 5167-5:2016
01-junij-2016

0HUMHQMHSUHWRNDIOXLGDQDRVQRYLWODþQHUD]OLNHSRY]URþHQH]QDSUDYRYVWDYOMHQR

YSROQR]DSROQMHQYRGVNURåQLPSUHUH]RPGHO6WRåþDVWDPHULOD ,62


Measurement of fluid flow by means of pressure differential devices inserted in circular

cross-section conduits running full - Part 5: Cone meters (ISO 5167-5:2016)

Durchflussmessung von Fluiden mit Drosselgeräten in voll durchströmten Leitungen mit

Kreisquerschnitt - Teil 5: Konus-Durchflussmesser (ISO 5167-5:2016)
Mesure de débit des fluides au moyen d'appareils déprimogènes insérés dans des

conduites en charge de section circulaire - Partie 5: Dispositifs de mesure avec cône de

mesure (ISO 5167-5:2016)
Ta slovenski standard je istoveten z: EN ISO 5167-5:2016
ICS:
17.120.10 Pretok v zaprtih vodih Flow in closed conduits
SIST EN ISO 5167-5:2016 en,fr,de

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

---------------------- Page: 1 ----------------------
SIST EN ISO 5167-5:2016
---------------------- Page: 2 ----------------------
SIST EN ISO 5167-5:2016
EN ISO 5167-5
EUROPEAN STANDARD
NORME EUROPÉENNE
March 2016
EUROPÄISCHE NORM
ICS 17.120.10
English Version
Measurement of fluid flow by means of pressure
differential devices inserted in circular cross-section
conduits running full - Part 5: Cone meters (ISO 5167-
5:2016)

Mesure de 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 5: Cônes de mesure (ISO Teil 5: Konus-Durchflussmesser (ISO 5167-5:2016)

5167-5:2016)
This European Standard was approved by CEN on 4 February 2016.

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, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania,

Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and

United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
CEN-CENELEC Management Centre: Avenue Marnix 17, B-1000 Brussels

© 2016 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 5167-5:2016 E

worldwide for CEN national Members.
---------------------- Page: 3 ----------------------
SIST EN ISO 5167-5:2016
EN ISO 5167-5:2016 (E)
Contents Page

European foreword ....................................................................................................................................................... 3

---------------------- Page: 4 ----------------------
SIST EN ISO 5167-5:2016
EN ISO 5167-5:2016 (E)
European foreword

This document (EN ISO 5167-5:2016) has been prepared by Technical Committee ISO/TC 30

"Measurement of fluid flow in closed conduits".

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 2016, and conflicting national standards

shall be withdrawn at the latest by September 2016.

Attention is drawn to the possibility that some of the elements of this document may be the subject of

patent rights. CEN [and/or CENELEC] shall not be held responsible for identifying any or all such patent

rights.

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, Former Yugoslav Republic of Macedonia, France,

Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands,

Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the

United Kingdom.
Endorsement notice

The text of ISO 5167-5:2016 has been approved by CEN as EN ISO 5167-5:2016 without any

modification.
---------------------- Page: 5 ----------------------
SIST EN ISO 5167-5:2016
---------------------- Page: 6 ----------------------
SIST EN ISO 5167-5:2016
INTERNATIONAL ISO
STANDARD 5167-5
First edition
2016-03-01
Measurement of fluid flow by means of
pressure differential devices inserted
in circular cross-section conduits
running full —
Part 5:
Cone meters
Mesure de débit des fluides au moyen d’appareils déprimogènes
insérés dans des conduites en charge de section circulaire —
Partie 5: Cônes de mesure
Reference number
ISO 5167-5:2016(E)
ISO 2016
---------------------- Page: 7 ----------------------
SIST EN ISO 5167-5:2016
ISO 5167-5:2016(E)
COPYRIGHT PROTECTED DOCUMENT
© ISO 2016, Published in Switzerland

All rights reserved. Unless otherwise specified, 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
Ch. de Blandonnet 8 • CP 401
CH-1214 Vernier, Geneva, Switzerland
Tel. +41 22 749 01 11
Fax +41 22 749 09 47
copyright@iso.org
www.iso.org
ii © ISO 2016 – All rights reserved
---------------------- Page: 8 ----------------------
SIST EN ISO 5167-5:2016
ISO 5167-5:2016(E)
Contents Page

Foreword ........................................................................................................................................................................................................................................iv

Introduction ..................................................................................................................................................................................................................................v

1 Scope ................................................................................................................................................................................................................................. 1

2 Normative references ...................................................................................................................................................................................... 1

3 Terms and definitions ..................................................................................................................................................................................... 1

4 Principles of the method of measurement and computation ................................................................................ 2

5 Cone meters ............................................................................................................................................................................................................... 3

5.1 Field of application .............................................................................................................................................................................. 3

5.2 General shape ........................................................................................................................................................................................... 4

5.3 Material and manufacture ............................................................................................................................................................. 7

5.4 Pressure tappings ................................................................................................................................................................................. 8

5.5 Discharge coefficient, C .....................................................................................................................................................................8

5.5.1 Limits of use ......................................................................................................................................................................... 8

5.5.2 Discharge coefficient of the cone meter ...................................................................................................... 8

5.6 Expansibility (expansion) factor, ε ..........................................................................................................................................9

5.7 Uncertainty of the discharge coefficient, C ......................................................................................................................9

5.8 Uncertainty of the expansibility (expansion) factor, ε ...........................................................................................9

5.9 Pressure loss ............................................................................................................................................................................................. 9

6 Installation requirements........................................................................................................................................................................10

6.1 General ........................................................................................................................................................................................................10

6.2 Minimum upstream and downstream straight lengths for installations between

various fittings and the cone meter ...................................................................................................................................10

6.2.1 General...................................................................................................................................................................................10

6.2.2 Single 90° bend .................. .................................................... .........................................................................................11

6.2.3 Two 90° bends in perpendicular planes ...................................................................................................11

6.2.4 Concentric expander .................................................................................................................................................11

6.2.5 Partially closed valves ..............................................................................................................................................11

6.3 Additional specific installation requirements for cone meters ..................................................................11

6.3.1 Circularity and cylindricality of the pipe .................................................................................................11

6.3.2 Roughness of the upstream and downstream pipe ........................................................................11

6.3.3 Positioning of a thermowell ................................................................................................................................11

7 Flow calibration of cone meters ........................................................................................................................................................12

7.1 General ........................................................................................................................................................................................................12

7.2 Test facility ...............................................................................................................................................................................................12

7.3 Meter installation...............................................................................................................................................................................12

7.4 Design of the test programme .................................................................................................................................................12

7.5 Reporting the calibration results .........................................................................................................................................13

7.6 Uncertainty analysis of the calibration ...........................................................................................................................13

7.6.1 General...................................................................................................................................................................................13

7.6.2 Uncertainty of the test facility ...........................................................................................................................13

7.6.3 Uncertainty of the cone meter ..........................................................................................................................13

Annex A (informative) Table of expansibility (expansion) factor .......................................................................................14

Bibliography .............................................................................................................................................................................................................................15

© ISO 2016 – All rights reserved iii
---------------------- Page: 9 ----------------------
SIST EN ISO 5167-5:2016
ISO 5167-5:2016(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 on the meaning of ISO specific terms and expressions related to conformity

assessment, as well as information about ISO’s adherence to the WTO principles in the Technical

Barriers to Trade (TBT) see the following URL: Foreword - Supplementary information

The committee responsible for this document is ISO/TC 30, Measurement of fluid flow in closed conduits,

Subcommittee SC 2, Pressure differential devices.

The first edition of ISO 5167-5 is complementary to ISO 5167-1, ISO 5167-2, ISO 5167-3, and ISO 5167-4.

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
— Part 5: Cone meters
iv © ISO 2016 – All rights reserved
---------------------- Page: 10 ----------------------
SIST EN ISO 5167-5:2016
ISO 5167-5:2016(E)
Introduction

This International Standard, divided into five parts, covers the geometry and method of use (installation

and operating conditions) of orifice plates, nozzles, Venturi tubes, and cone meters when they are

inserted in a conduit running full to determine the flow rate of the fluid in the conduit. It also gives

necessary information for calculating the flow rate and its associated uncertainty.

This International Standard 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

it 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.

This International Standard 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. However, for

cone meters calibrated in accordance with Clause 7, a wider range of pipe size, β, and Reynolds number

may be considered.

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

[1][5]

“secondary devices”. This International Standard covers primary devices; secondary devices will

be mentioned only occasionally.
This International Standard is divided into the following five 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 conjunction with ISO 5167-1,

ISO 5167-2, ISO 5167-3, ISO 5167-4, and ISO 5167-5.

b) ISO 5167-2 specifies requirements for orifice plates, which can be used with corner pressure

tappings, D and D/2 pressure tappings , and flange pressure tappings.

c) ISO 5167-3 specifies requirements for ISA 1932 nozzles , long radius nozzles, and Venturi nozzles,

which differ in shape and in the position of the pressure tappings.
d) ISO 5167-4 specifies requirements for classical Venturi tubes .

e) This part of ISO 5167 specifies requirements for cone meters and includes a section on calibration.

Aspects of safety are not dealt with in ISO 5167 (all parts). It is the responsibility of the user to ensure

that the system meets applicable safety regulations.

1) Orifice plates with ‘vena contracta’ pressure tappings are not considered in ISO 5167 (all parts).

2) ISA is the abbreviation for the International Federation of the National Standardizing Associations, which was

succeeded by ISO in 1946.

3) In the USA, the classical Venturi tube is sometimes called the Herschel Venturi tube.

© ISO 2016 – All rights reserved v
---------------------- Page: 11 ----------------------
SIST EN ISO 5167-5:2016
---------------------- Page: 12 ----------------------
SIST EN ISO 5167-5:2016
INTERNATIONAL STANDARD ISO 5167-5:2016(E)
Measurement of fluid flow by means of pressure
differential devices inserted in circular cross-section
conduits running full —
Part 5:
Cone meters
1 Scope

This part of ISO 5167 specifies the geometry and method of use (installation and operating conditions)

of cone meters when they are inserted in a conduit running full to determine the flow rate of the fluid

flowing in the conduit.

As the uncertainty of an uncalibrated cone meter might be too high for a particular application, it might

be deemed essential to calibrate the flow meter in accordance with Clause 7.

This part of ISO 5167 also provides background information for calculating the flow rate and is

applicable in conjunction with the requirements given in ISO 5167-1.

This part of ISO 5167 is applicable only to cone meters in which the flow remains subsonic throughout

the measuring section and where the fluid can be considered as single-phase. Uncalibrated cone meters

can only be used within specified limits of pipe size, roughness, β, and Reynolds number. This part of

ISO 5167 is not applicable to the measurement of pulsating flow. It does not cover the use of uncalibrated

cone meters in pipes sized less than 50 mm or more than 500 mm, or where the pipe Reynolds numbers

4 7
are below 8 × 10 or greater than 1,2 × 10 .

A cone meter is a primary device which consists of a cone-shaped restriction held concentrically in the

centre of the pipe with the nose of the cone upstream. The design of cone meter defined in this part of

ISO 5167 has one or more upstream pressure tappings in the wall, and a downstream pressure tapping

positioned in the back face of the cone with the connection to a differential pressure transmitter being

a hole through the cone to the support bar, and then up through the support bar.

Alternative designs of cone meters are available; however, at the time of writing, there is insufficient

data to fully characterize these devices, and therefore, these meters shall be calibrated in accordance

with Clause 7.
2 Normative references

The following documents, in whole or in part, are normatively referenced in this document and are

indispensable for its application. For dated references, only the edition cited applies. For undated

references, the latest edition of the referenced document (including any amendments) applies.

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

3 Terms and definitions

For the purposes of this document, the terms and definitions given in ISO 4006, ISO 5167-1, and the

following apply.
© ISO 2016 – All rights reserved 1
---------------------- Page: 13 ----------------------
SIST EN ISO 5167-5:2016
ISO 5167-5:2016(E)
3.1
beta edge
maximum circumference of the cone
4 Principles of the method of measurement and computation

The principle of the method of measurement is based on the installation of the cone meter into a pipeline

in which a fluid is running full. Flow through a cone meter produces a differential pressure between the

upstream and downstream tappings.
The mass flow rate can be determined by Formulae (1) and (2):
C π
q = ε Dpβρ2Δ (1)
m 1
1−β
and
β =−1 (2)

where d is the diameter of the cone in the plane of the beta edge. This assumes that the diameter of

the pipe at the upstream tapping, D , is equal to the diameter of the pipe at the beta edge, D. Figure 1

TAP
shows that as the cone diameter increases, β decreases.
Key
1 flow
Figure 1 — Cone meter showing different values of β
2 © ISO 2016 – All rights reserved
---------------------- Page: 14 ----------------------
SIST EN ISO 5167-5:2016
ISO 5167-5:2016(E)

The uncertainty limits can be calculated using the procedure given in ISO 5167-1:2003, Clause 8, except

that Formula (3) should be used instead of ISO 5167-1:2003, Formula (3)
12/
 2 2 2
22 2
   
 
δq δd   δρρ 
δδC   ε  21()++ββ δD 2 1 δDp 1
m c 1
 
= + +  +  + +
   
 
     
22 22
     
q C ε D d 4 Dp 4 ρ
    ββ()1+   ββ()1+
m  c     1 
 
 
 
 
(3)
Similarly, the value of the volume flow rate can be calculated since
q = (4)

where ρ is the fluid density at the temperature and pressure for which the volume is stated.

Computation of the flow rate, 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. Formula (5) in 5.6 (or

the computed values in Table A.1) gives cone meter expansibility factors (ε). The values in Table A.1

are not intended for precise interpolation. Extrapolation is not permitted. However, the coefficient

of discharge, C, is generally dependent on the Reynolds number, Re, which is itself dependent on q ,

and has to be obtained by iteration (see ISO 5167-1:2003, Annex A for guidance regarding the choice of

iteration procedure and initial estimates).

The diameters, d and D, mentioned in Formulae (1) and (2) 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.

As the cone meter flow rate calculation is particularly sensitive to the pipe and cone diameter values

used, the user shall ensure that these are correctly entered into the flow computation calculations. For

example, care shall be taken to use the measured internal diameter rather than a nominal value.

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.

NOTE The turndown of all differential pressure flow meters is dependent upon the differential pressure

range. Typically, a 10:1 turndown in flow rate (equivalent to 100:1 turndown in differential pressure) can be

achieved.
5 Cone meters
5.1 Field of application

Uncalibrated cone meters can be used in pipes with diameters between 50 mm and 500 mm and with

0,45 ≤ β ≤ 0,75. Cone meters with β > 0,75 shall be calibrated. Cone meters with values of β < 0,45 are

not normally manufactured.
There are limits to the roughness and Reynolds number which shall be addressed.
© ISO 2016 – All rights reserved 3
---------------------- Page: 15 ----------------------
SIST EN ISO 5167-5:2016
ISO 5167-5:2016(E)
5.2 General shape

5.2.1 Figure 2 shows a section through the centreline of a cone meter. Figure 4 shows other sections

through the meter to aid in the metrology of the cone meter. The letters used in the text refer to those

shown in Figure 2 and Figure 4.

The cone meter is made up of a pipe section of diameter, D, which houses the cone assembly with cone

diameter, d , the support structure for the cone, and the tappings for differential pressure measurement.

The cone assembly is installed such that the cone centreline is concentric to the centreline of the pipe

section, as per 5.2.13.
Key
1 flow
2 body pipe
3 cone element
4 support strut
5 high pressure tapping
6 low pressure tapping
7 cone nose
NOTE 50 mm ≤ L ≤ 2D, as defined in 5.4.7.
Figure 2 — Geometric profile of cone meter
4 © ISO 2016 – All rights reserved
---------------------- Page: 16 ----------------------
SIST EN ISO 5167-5:2016
ISO 5167-5:2016(E)

5.2.2 The design of the nose of the cone (for examples, see Figure 3) can be constructed as a machined

component or from an elbow. The nose shall be downstream of the plane of the centreline of the upstream

tapping(s). It is recommended that the nose be as short as practicable.
These designs shown in Figure 3 should not be considered exclusive.
a) Flat b) Pointed c) Curved d) Elbow
Figure 3 — Examples of different cone nose designs

5.2.3 The pipe diameter, D, shall be measured at plane A of Figure 4. The number of measurements

shall be a minimum of four equally spaced around the pipe internal circumference. The arithmetic mean

value of these measurements shall be taken as the value of D in the calculations.

5.2.4 The pipe diameter shall also be measured at plane C of Figure 4 (shown as D in Figure 2). The

TAP

number of measurements at this plane shall be at least equal to the number of pressure tappings (with a

minimum of four).

5.2.5 No diameter at any point between plane C and 1D downstream of plane A from Figure 4 shall

differ from the pipe diameter, D, by more than 1,0 %.
© ISO 2016 – All rights reserved 5
---------------------- Page: 17 ----------------------
SIST EN ISO 5167-5:2016
ISO 5167-5:2016(E)
Key
1 flow
2 cone nose
Figure 4 — Metrology data for a cone meter

5.2.6 The internal surface of the pipe section from plane C to plane A from Figure 4 shall be clean and

smooth, and the roughness criterion, Ra, should be as small as possible and shall be less than 10 D.

5.2.7 The cone assembly shall generally consist of a circular bifrustum (two truncated cones joined

at their widest points). The upstream frustum shall have a single internal angle, θ , of 26° ± 5° to the

centreline of the frusta. The downstream frustum shall have a single internal angle, θ , of 67,5° ± 2,5° to

the centreline of the frusta.

5.2.8 The cone diameter, d , shall be measured at plane A of Figure 4. There shall be a minimum of four

measurements equally spaced around the cone external circumference.

The arithmetic mean value of these measurements shall be taken as the value of d in the calculations.

No diameter shall diff
...

Questions, Comments and Discussion

Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.