Industrial-process control valves - Part 2-1: Flow capacity - Sizing equations for fluid flow under installed conditions

Includes equations for predicting the fow of compressible and incompressible fluids through control valves. Not intended for use when non-Newtonian fluids, fluid mixtures, slurries, or liquid-solid conveyance systems are encoutnererd. Equations for compressible fluids are for use with gas or vapour and are not inteded for use with multiphase streams such as gas-liquid, vapour-liquid or gas-solid mixtures. Valid for valves with xT smaller or equal to 0,84. The contents of the corrigendum of February 2000 have been included in this copy.

Vannes de régulation des processus industriels - Partie 2-1: Capacité d'écoulement - Equations de dimensionnement des vannes de régulation pour l'écoulement des fluides dans les conditions d'installation

Le contenu du corrigendum de février 2000 a été pris en considération dans cet exemplaire.

General Information

Status
Published
Publication Date
31-Aug-1998
Current Stage
DELPUB - Deleted Publication
Completion Date
30-Mar-2011
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IEC 60534-2-1:1998 - Industrial-process control valves - Part 2-1: Flow capacity - Sizing equations for fluid flow under installed conditions Released:9/1/1998
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IEC 60534-2-1:1998 - Industrial-process control valves - Part 2-1: Flow capacity - Sizing equations for fluid flow under installed conditions Released:9/1/1998 Isbn:2831845033
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INTERNATIONAL
IEC
STANDARD
60534-2-1
First edition
1998-09
Industrial-process control valves –
Part 2-1:
Flow capacity –
Sizing equations for fluid flow
under installed conditions
Vannes de régulation des processus industriels –
Partie 2-1:
Capacité d’écoulement –
Equations de dimensionnement des vannes
de régulation pour l’écoulement des fluides
dans les conditions d’installation
Reference number
Numbering
As from 1 January 1997 all IEC publications are issued with a designation in the
60000 series.
Consolidated publications
Consolidated versions of some IEC publications including amendments are
available. For example, edition numbers 1.0, 1.1 and 1.2 refer, respectively, to the
base publication, the base publication incorporating amendment 1 and the base
publication incorporating amendments 1 and 2.
Validity of this publication
The technical content of IEC publications is kept under constant review by the IEC,
thus ensuring that the content reflects current technology.
Information relating to the date of the reconfirmation of the publication is available
in the IEC catalogue.
Information on the subjects under consideration and work in progress undertaken by
the technical committee which has prepared this publication, as well as the list of
publications issued, is to be found at the following IEC sources:
• IEC web site*
• Catalogue of IEC publications
Published yearly with regular updates
(On-line catalogue)*
• IEC Bulletin
Available both at the IEC web site* and as a printed periodical
Terminology, graphical and letter symbols
For general terminology, readers are referred to IEC 60050: International Electro-
technical Vocabulary (IEV).
For graphical symbols, and letter symbols and signs approved by the IEC for
general use, readers are referred to publications IEC 60027: Letter symbols to be
used in electrical technology, IEC 60417: Graphical symbols for use on equipment.
Index, survey and compilation of the single sheets and IEC 60617: Graphical symbols
for diagrams.
* See web site address on title page.

INTERNATIONAL
IEC
STANDARD
60534-2-1
First edition
1998-09
Industrial-process control valves –
Part 2-1:
Flow capacity –
Sizing equations for fluid flow
under installed conditions
Vannes de régulation des processus industriels –
Partie 2-1:
Capacité d’écoulement –
Equations de dimensionnement des vannes
de régulation pour l’écoulement des fluides
dans les conditions d’installation
 IEC 1998  Copyright - all rights reserved
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 the publisher.
International Electrotechnical Commission 3, rue de Varembé Geneva, Switzerland
Telefax: +41 22 919 0300 e-mail: inmail@iec.ch IEC web site http: //www.iec.ch
Commission Electrotechnique Internationale
PRICE CODE X
International Electrotechnical Commission
For price, see current catalogue

– 2 – 60534-2-1 © IEC:1998(E)
CONTENTS
Page
FOREWORD . 3
Clause
1 Scope . 4
2 Normative references . 4
3 Definitions. 5
4 Installation . 5
5 Symbols . 6
6 Sizing equations for incompressible fluids. 7
7 Sizing equations for compressible fluids . 9
8 Determination of correction factors . 11
Annex A – Derivation of valve style modifier F . 25
d
Annex B – Control valve sizing flow charts . 29
Annex C – Physical constants . 33
Annex D – Examples of sizing calculations. 34
Annex E – Bibliography. 45

60534-2-1 © IEC:1998(E) – 3 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION
––––––––––––
INDUSTRIAL-PROCESS CONTROL VALVES –
Part 2-1: Flow capacity – Sizing equations for fluid flow
under installed conditions
FOREWORD
1) The IEC (International Electrotechnical Commission) is a worldwide organization for standardization comprising
all national electrotechnical committees (IEC National Committees). The object of the IEC is to promote
international co-operation on all questions concerning standardization in the electrical and electronic fields. To
this end and in addition to other activities, the IEC publishes International Standards. Their preparation is
entrusted to technical committees; any IEC National Committee interested in the subject dealt with may
participate in this preparatory work. International, governmental and non-governmental organizations liaising
with the IEC also participate in this preparation. The IEC collaborates closely with the International Organization
for Standardization (ISO) in accordance with conditions determined by agreement between the two
organizations.
2) The formal decisions or agreements of the IEC on technical matters express, as nearly as possible, an
international consensus of opinion on the relevant subjects since each technical committee has representation
from all interested National Committees.
3) The documents produced have the form of recommendations for international use and are published in the form
of standards, technical reports or guides and they are accepted by the National Committees in that sense.
4) In order to promote international unification, IEC National Committees undertake to apply IEC International
Standards transparently to the maximum extent possible in their national and regional standards. Any
divergence between the IEC Standard and the corresponding national or regional standard shall be clearly
indicated in the latter.
5) The IEC provides no marking procedure to indicate its approval and cannot be rendered responsible for any
equipment declared to be in conformity with one of its standards.
6) Attention is drawn to the possibility that some of the elements of this International Standard may be the subject
of patent rights. The IEC shall not be held responsible for identifying any or all such patent rights.
International Standard IEC 60534-2-1 has been prepared by subcommittee 65B: Devices, of
IEC technical committee 65: Industrial-process measurement and control.
The text of this standard is based on the following documents:
FDIS Report on voting
65B/347/FDIS 65B/357/RVD
Full information on the voting for the approval of this standard can be found in the report on
voting indicated in the above table.
The edition of IEC 60534-2-1 cancels and replaces the first edition of both IEC 60534-2
published in 1978, and IEC 60534-2-2 published in 1980, which cover incompressible and
compressible fluid flow, respectively.
IEC 60534-2-1 covers sizing equations for both incompressible and compressible fluid flow.
Annexes A, B, C, D and E are for information only.
A bilingual version of this standard may be issued at a later date.

– 4 – 60534-2-1 © IEC:1998(E)
INDUSTRIAL-PROCESS CONTROL VALVES –
Part 2-1: Flow capacity – Sizing equations for fluid flow
under installed conditions
1 Scope
This part of IEC 60534 includes equations for predicting the flow of compressible and
incompressible fluids through control valves.
The equations for incompressible flow are based on standard hydrodynamic equations for
Newtonian incompressible fluids. They are not intended for use when non-Newtonian fluids,
fluid mixtures, slurries, or liquid-solid conveyance systems are encountered.
At very low ratios of pressure differential to absolute inlet pressure (Δp/p ), compressible fluids
behave similarly to incompressible fluids. Under such conditions, the sizing equations for
compressible flow can be traced to the standard hydrodynamic equations for Newtonian
incompressible fluids. However, increasing values of Δp/p result in compressibility effects
which require that the basic equations be modified by appropriate correction factors. The
equations for compressible fluids are for use with gas or vapour and are not intended for use
with multiphase streams such as gas-liquid, vapour-liquid or gas-solid mixtures.
For compressible fluid applications, this part of IEC 60534 is valid for valves with x ≤ 0,84
T
(see table 2). For valves with x > 0,84 (e.g. some multistage valves), greater inaccuracy of
T
flow prediction can be expected.
Reasonable accuracy can only be maintained for control valves if K /d < 0,04 (C /d < 0,047).
v v
2 Normative references
The following normative documents contain provisions which, through reference in this text,
constitute provisions of this part of IEC 60534. At the time of publication, the editions indicated
were valid. All normative documents are subject to revision, and parties to agreements based
on this part of IEC 60534 are encouraged to investigate the possibility of applying the most
recent editions of the normative documents indicated below. Members of IEC and ISO maintain
registers of currently valid International Standards.
IEC 60534-1:1987, Industrial-process control valves – Part 1: Control valve terminology and
general considerations
IEC 60534-2-3:1997, Industrial-process control valves – Part 2: Flow capacity – Section 3: Test
procedures
60534-2-1 © IEC:1998(E) – 5 –
3 Definitions
For the purpose of this part of IEC 60534, definitions given in IEC 60534-1 apply with the
addition of the following:
3.1
valve style modifier F
d
The ratio of the hydraulic diameter of a single flow passage to the diameter of a circular
orifice, the area of which is equivalent to the sum of areas of all identical flow passages at a
given travel. It should be stated by the manufacturer as a function of travel. See annex A.
4 Installation
In many industrial applications, reducers or other fittings are attached to the control valves. The
effect of these types of fittings on the nominal flow coefficient of the control valve can be
significant. A correction factor is introduced to account for this effect. Additional factors are
introduced to take account of the fluid property characteristics that influence the flow capacity
of a control valve.
In sizing control valves, using the relationships presented herein, the flow coefficients calculated
are assumed to include all head losses between points A and B, as shown in figure 1.
Flow
l l
I1 I2
Pressure
1 2 Pressure
Pressure
Pressure
tap
tap
tap
tap
A B
Control valve with or without attached fittings
l = two nominal pipe diameters
l = six nominal pipe diameters
Figure 1 – Reference pipe section for sizing

– 6 – 60534-2-1 © IEC:1998(E)
5 Symbols
Symbol Description Unit
C Flow coefficient (K , C ) Various (see IEC 60534-1)
v v
(see note 4)
C Assumed flow coefficient for iterative purposes Various (see IEC 60534-1)
i
(see note 4)
d Nominal valve size mm
D Internal diameter of the piping mm
D Internal diameter of upstream piping mm
D Internal diameter of downstream piping mm
D Orifice diameter mm
o
F Valve style modifier (see annex A) 1 (see note 4)
d
F Liquid critical pressure ratio factor 1
F
F Liquid pressure recovery factor of a control valve without attached fittings 1 (see note 4)
L
F Combined liquid pressure recovery factor and piping geometry factor of a 1 (see note 4)
LP
control valve with attached fittings
F Piping geometry factor 1
P
F Reynolds number factor 1
R
F Specific heat ratio factor 1
γ
M Molecular mass of flowing fluid kg/kmol
N Numerical constants (see table 1) Various (see note 1)
p Inlet absolute static pressure measured at point A (see figure 1) kPa or bar (see note 2)
p Outlet absolute static pressure measured at point B (see figure 1) kPa or bar
p Absolute thermodynamic critical pressure kPa or bar
c
p Reduced pressure (p /p )
r 1 c
p Absolute vapour pressure of the liquid at inlet temperature kPa or bar
v
Differential pressure between upstream and downstream pressure taps kPa or bar
Δp
(p – p )
1 2
Q Volumetric flow rate (see note 5) m /h
Re Valve Reynolds number 1
v
T Inlet absolute temperature K
T Absolute thermodynamic critical temperature K
c
T Reduced temperature (T /T ) 1
r 1 c
t Absolute reference temperature for standard cubic metre K
s
W Mass flow rate kg/h
x 1
Ratio of pressure differential to inlet absolute pressure (Δp/p )
x Pressure differential ratio factor of a control valve without attached fittings 1 (see note 4)
T
at choked flow
x Pressure differential ratio factor of a control valve with attached fittings at 1 (see note 4)
TP
choked flow
Y Expansion factor 1
Compressibility factor 1
Z
ν Kinematic viscosity m /s (see note 3)
ρ Density of fluid at p and T kg/m
1 1 1
ρ /ρ Relative density (ρ /ρ = 1,0 for water at 15 °C) 1
1 o 1 o
Specific heat ratio 1
γ
60534-2-1 © IEC:1998(E) – 7 –
Velocity head loss coefficient of a reducer, expander or other fitting 1
ζ
attached to a control valve or valve trim
ζ Upstream velocity head loss coefficient of fitting 1
ζ Downstream velocity head loss coefficient of fitting 1
Inlet Bernoulli coefficient 1
ζ
B1
Outlet Bernoulli coefficient 1
ζ
B2
NOTE 1 – To determine the units for the numerical constants, dimensional analysis may be performed on the
appropriate equations using the units given in table 1.
2 5
NOTE 2 – 1 bar = 10 kPa = 10 Pa
–6 2
NOTE 3 – 1 centistoke = 10 m /s
NOTE 4 – These values are travel-related and should be stated by the manufacturer.
NOTE 5 – Volumetric flow rates in cubic metres per hour, identified by the symbol Q, refer to standard conditions.
The standard cubic metre is taken at 1013,25 mbar and either 273 K or 288 K (see table 1).
6 Sizing equ
...


IEC 60534-2-1
Edition 1.0 1998-09
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Industrial-process control valves –
Part 2-1: Flow-capacity – Sizing equations for fluid flow under installed
conditions
Vannes de régulation des processus industriels –
Partie 2-1: Capacité d’écoulement – Equations de dimensionnement pour
l’écoulement des fluides dans les conditions d’installation

Copyright © 1998 IEC, Geneva, Switzerland

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 IEC or
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IEC 60534-2-1
Edition 1.0 1998-09
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Industrial-process control valves –
Part 2-1: Flow-capacity – Sizing equations for fluid flow under installed
conditions
Vannes de régulation des processus industriels –
Partie 2-1: Capacité d’écoulement – Equations de dimensionnement pour
l’écoulement des fluides dans les conditions d’installation

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
PRICE CODE
INTERNATIONALE
X
CODE PRIX
ICS 23.060.40; 25.040.40 ISBN 2-8318-4751-6
– 2 – 60534-2-1 © CEI:1998
SOMMAIRE
Pages
AVANT-PROPOS . 4
Articles
1 Domaine d'application . 6
2 Références normatives. 6
3 Définitions. 8
4 Installation . 8
5 Symboles .10
6 Equations de dimensionnement pour fluides incompressibles . 12
7 Equations de dimensionnement pour fluides compressibles . 16
8 Détermination des facteurs de correction. 20
Annexe A (informative) Calcul du coefficient de correction générique de vanne F . 48
d
Annexe B (informative) Organigramme de dimensionnement des vannes de régulation . 58
Annexe C (informative) Constantes physiques . 66
Annexe D (informative) Exemples de calculs de dimensionnement . 68
Annexe E (informative) Bibliographie . 90

60534-2-1 © IEC:1998 – 3 –
CONTENTS
Page
FOREWORD . 5
Clause
1 Scope . 7
2 Normative references . 7
3 Definitions. 9
4 Installation . 9
5 Symbols . 11
6 Sizing equations for incompressible fluids. 13
7 Sizing equations for compressible fluids . 17
8 Determination of correction factors . 21
Annex A (informative) Derivation of valve style modifier F . 49
d
Annex B (informative) Control valve sizing flow charts. 59
Annex C (informative) Physical constants . 67
Annex D (informative) Examples of sizing calculations . 69
Annex E (informative) Bibliography . 91

– 4 – 60534-2-1 © CEI:1998
COMMISSION ÉLECTROTECHNIQUE INTERNATIONALE
____________
VANNES DE RÉGULATION DES PROCESSUS INDUSTRIELS –
Partie 2-1: Capacité d'écoulement –
Equations de dimensionnement pour l'écoulement des fluides
dans les conditions d'installation
AVANT-PROPOS
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La Norme internationale CEI 60534-2-1 a été établie par le sous-comité 65B: Dispositifs, du
comité d'études 65 de la CEI: Mesure et commande dans les processus industriels.
La CEI 60534-2-1 annule et remplace la première édition de la CEI 60534-2, publiée en 1978,
et de la CEI 60534-2-2, publiée en 1980, qui couvraient respectivement les fluides
incompressibles et compressibles.
La CEI 60534-2-1 couvre les équations de dimensionnement à la fois des fluides
compressibles et incompressibles.
La présente version bilingue, publiée en 1999-03, correspond à la version anglaise.
Le texte anglais de cette norme est basé sur les documents 65B/347/FDIS et 65B/357/RVD. Le
rapport de vote 65B/357/RVD donne toute information sur le vote ayant abouti à l'approbation
de cette norme.
La version française de cette norme n'a pas été soumise au vote.
Les annexes A, B, C, D et E sont données uniquement à titre d'information.
Le contenu du corrigendum de février 2000 a été pris en considération dans cet exemplaire.

60534-2-1 © IEC:1998 – 5 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION
––––––––––––
INDUSTRIAL-PROCESS CONTROL VALVES –
Part 2-1: Flow capacity – Sizing equations for fluid flow
under installed conditions
FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
all national electrotechnical committees (IEC National Committees). The object of IEC is to promote
international co-operation on all questions concerning standardization in the electrical and electronic fields. To
this end and in addition to other activities,
...

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