SIST EN IEC 60953-3:2022

Rules for steam turbine thermal acceptance tests - Part 3: Thermal performance verification tests of retrofitted steam turbines (IEC 60953-3:2022)

This part of IEC 60953 establishes a Supplementary Standard (SS) for thermal verification tests of retrofitted steam turbines.
The rules given in this SS follow the guidance given in IEC 60953-0, hereinafter called the Reference Standard (RS) but contain amendments and supplements regarding guarantees and verification of the guarantees by thermal acceptance tests on retrofitted steam turbines.
General principles for the preparation, performance, evaluation, comparison with guaranteed values and the determination of the measurement uncertainties of verification tests are given in this SS.
This SS is applicable only when the retrofit involves some hardware change in the steam turbine equipment. Conversely, any modification on the cycle or any retrofit of other equipment of the power plant (e.g. boiler, feedwater heaters, etc.) is not covered by this SS.

Regeln für thermische Abnahmeprüfungen für Dampfturbinen - Teil 3: Thermische Leistungsangabenüberprüfung für modernisierte Dampfturbinen (IEC 60953-3:2022)

Règles pour les essais thermiques de réception des turbines à vapeur - Partie 3: Essais de vérification des performances thermiques des turbines à vapeur rénovées (IEC 60953-3:2022)

IEC 60953-3:2022 La présente partie établit une norme supplémentaire pour les essais de vérification thermique des turbines à vapeur modernisées.
Les règles données dans le présent document suivent les directives données dans la CEI 60953-0, mais contiennent des amendements et des suppléments concernant les garanties et la vérification des garanties par des essais de réception thermique sur des turbines à vapeur modernisées.
Les principes généraux pour la préparation, l’exécution, l’évaluation, la comparaison avec les valeurs garanties et la détermination des incertitudes de mesure des essais de vérification sont donnés dans le présent document.
Le présent document ne s’applique que lorsque la mise à niveau implique un changement de matériel dans l’équipement de la turbine à vapeur. Inversement, toute modification du cycle ou toute modernisation d’autres équipements de la centrale (par exemple chaudière, chauffe-eau, etc.) n’est pas couverte par le présent document.

Pravila za preskuse toplotne sprejemljivosti parne turbine - 3. del: Preskusi preverjanja toplotne učinkovitosti naknadno vgrajenih parnih turbin (IEC 60953-3:2022)

Ta del standarda IEC 60953 določa dodatni standard (SS) za preskuse preverjanja toplotne učinkovitosti naknadno vgrajenih parnih turbin.
Pravila, podana v tem dodatnem standardu, sledijo smernicam iz standarda IEC 60953-0 (v nadaljevanju: referenčni standard (RS)), vendar vključujejo spremembe in dopolnitve v zvezi z jamstvi in preverjanjem jamstev s preskusi toplotne sprejemljivosti naknadno vgrajenih parnih turbin.
V tem dodatnem standardu so podana splošna načela za pripravo, delovanje, vrednotenje, primerjavo z zajamčenimi vrednostmi in ugotavljanje merilne negotovosti preskusov preverjanja.
Ta dodatni standard se uporablja le, kadar naknadna vgradnja vključuje zamenjavo strojne opreme v parni turbini. Nasprotno pa ta dodatni standard ne zajema morebitnih sprememb v ciklu ali morebitne naknadne vgradnje druge opreme elektrarne (npr. kotla, grelnikov napajalne vode itd.).

General Information

• Status: Published
• Publication Date: 19-Sep-2022
• ICS: 27.040 - Gas and steam turbines. Steam engines
• Technical Committee: I10 - Imaginarni 10 za neaktivna TDT na elektro področju
• Current Stage: 6060 - National Implementation/Publication (Adopted Project)
• Start Date: 16-Sep-2022
• Due Date: 21-Nov-2022
• Completion Date: 20-Sep-2022
• Ref Project: EN IEC 60953-3:2022 - Rules for steam turbine thermal acceptance tests - Part 3: Thermal performance verification tests of retrofitted steam turbines

Relations

• Replaces: SIST EN 60953-3:2002 - Rules for steam turbine thermal acceptance tests -- Part 3: Thermal performance verification tests of retrofitted steam turbines
• Effective Date: 13-Sep-2022
• Revised: SIST EN 60953-3:2002 - Rules for steam turbine thermal acceptance tests -- Part 3: Thermal performance verification tests of retrofitted steam turbines
• Effective Date: 09-Oct-2018

Standards Content (Sample)

SLOVENSKI STANDARD
01-november-2022
Nadomešča:
SIST EN 60953-3:2002
Pravila za preskuse toplotne sprejemljivosti parne turbine - 3. del: Preskusi
preverjanja toplotne učinkovitosti naknadno vgrajenih parnih turbin (IEC 60953-
3:2022)
Rules for steam turbine thermal acceptance tests - Part 3: Thermal performance
verification tests of retrofitted steam turbines (IEC 60953-3:2022)
Regeln für thermische Abnahmeprüfungen für Dampfturbinen - Teil 3: Thermische
Leistungsangabenüberprüfung für modernisierte Dampfturbinen (IEC 60953-3:2022)
Règles pour les essais thermiques de réception des turbines à vapeur - Partie 3: Essais
de vérification des performances thermiques des turbines à vapeur rénovées (IEC 60953
-3:2022)
Ta slovenski standard je istoveten z: EN IEC 60953-3:2022
ICS:
27.040 Plinske in parne turbine. Gas and steam turbines.
Parni stroji Steam engines
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN STANDARD EN IEC 60953-3

NORME EUROPÉENNE
EUROPÄISCHE NORM September 2022
ICS 27.040 Supersedes EN 60953-3:2002
English Version
Rules for steam turbine thermal acceptance tests - Part 3:
Thermal performance verification tests of retrofitted steam
turbines
(IEC 60953-3:2022)
Règles pour les essais thermiques de réception des Regeln für thermische Abnahmeprüfungen für
turbines à vapeur - Partie 3: Essais de vérification des Dampfturbinen - Teil 3: Thermische
performances thermiques des turbines à vapeur rénovées Leistungsangabenüberprüfung für modernisierte
(IEC 60953-3:2022) Dampfturbinen
(IEC 60953-3:2022)
This European Standard was approved by CENELEC on 2022-08-24. CENELEC 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 CENELEC 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 CENELEC member into its own language and notified to the CEN-CENELEC Management Centre has the
same status as the official versions.
CENELEC members are the national electrotechnical committees of Austria, Belgium, Bulgaria, Croatia, Cyprus, the Czech Republic,
Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, the
Netherlands, Norway, Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland,
Türkiye and the United Kingdom.

European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung
CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2022 CENELEC All rights of exploitation in any form and by any means reserved worldwide for CENELEC Members.
Ref. No. EN IEC 60953-3:2022 E

European foreword
The text of document 5/249/FDIS, future edition 2 of IEC 60953-3, prepared by IEC/TC 5 "Steam
turbines" was submitted to the IEC-CENELEC parallel vote and approved by CENELEC as
The following dates are fixed:
• latest date by which the document has to be implemented at national (dop) 2023-05-24
level by publication of an identical national standard or by endorsement
• latest date by which the national standards conflicting with the (dow) 2025-08-24
document have to be withdrawn
This document supersedes EN 60953-3:2002 and all of its amendments and corrigenda (if any).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CENELEC shall not be held responsible for identifying any or all such patent rights.
Any feedback and questions on this document should be directed to the users’ national committee. A
complete listing of these bodies can be found on the CENELEC website.
Endorsement notice
The text of the International Standard IEC 60953-3:2022 was approved by CENELEC as a European
Standard without any modification.
Annex ZA
(normative)
Normative references to international publications
with their corresponding European publications
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.
NOTE 1  Where an International Publication has been modified by common modifications, indicated by (mod),
the relevant EN/HD applies.
NOTE 2  Up-to-date information on the latest versions of the European Standards listed in this annex is available
here: www.cenelec.eu.
Publication Year Title EN/HD Year
IEC 60953-0 -  Rules for steam turbine thermal EN IEC 60953-0 -
acceptance tests - Part 0: Wide range of
accuracy for various types and sizes of
turbines
IEC 60953-3 ®
Edition 2.0 2022-07
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Rules for steam turbine thermal acceptance tests –

Part 3: Thermal performance verification tests of retrofitted steam turbines

Règles pour les essais thermiques de réception des turbines à vapeur –

Partie 3: Essais de vérification des performances thermiques des turbines à

vapeur rénovées
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 27.040 ISBN 978-2-8322-3974-2

– 2 – IEC 60953-3:2022 © IEC 2022
CONTENTS
FOREWORD . 8
INTRODUCTION . 10
1 Scope . 13
1.1 General . 13
1.2 Object . 13
1.3 Matters to be considered in the contract . 13
2 Normative references . 13
3 Units, symbols, terms and definitions . 14
3.1 General . 14
3.2 Symbols, units . 14
3.3 Subscripts, superscripts and definitions . 14
3.4 Guarantee parameters . 16
3.4.1 Guidance on guarantee parameters . 16
3.4.2 Thermal efficiency . 16
3.4.3 Heat rate . 16
3.4.4 Thermodynamic efficiency . 16
3.4.5 Steam rate . 16
3.4.6 Main steam flow capacity . 16
3.4.7 Power output . 16
3.4.8 Guarantee values for extraction and mixed-pressure turbines . 16
3.4.9 Thermal Load Capacity (for Nuclear applications) . 16
3.5 Additional guarantee parameters . 16
3.5.1 General . 16
3.5.2 Cylinder isentropic efficiency – expansion in superheated region . 16
3.5.3 Cylinder isentropic efficiency – expansion involving wet region . 17
3.5.4 Pressure loss . 19
3.5.5 Flow-passing capacity (FPC) . 19
4 Guiding principles . 19
4.1 Advance planning for test . 19
4.2 Preparatory agreements and arrangements for tests . 20
4.3 Planning of the test . 20
4.3.1 Time for verification tests . 20
4.3.2 Direction of acceptance tests . 21
4.4 Preparation of the tests . 21
4.4.1 Condition of the plant. 21
4.4.2 Condition of the steam turbine . 22
4.4.3 Condition of the condenser . 22
4.4.4 Isolation of the cycle . 22
4.4.5 Checks for leakage of condenser and feed water heaters . 22
4.4.6 Cleanliness of the steam strainers . 22
4.4.7 Checking of the test measuring equipment . 22
4.5 Comparison measurements . 22
4.6 Settings for test . 23
4.6.1 Load settings . 23
4.6.2 Special settings . 23
4.7 Preliminary tests . 23
4.8 Acceptance tests . 23

IEC 60953-3:2022 © IEC 2022 – 3 –
4.8.1 Constancy of test conditions . 23
4.8.2 Maximum deviation and fluctuation in test conditions . 23
4.8.3 Duration of test runs and frequency of reading . 23
4.8.4 Reading of integrating measuring instruments . 23
4.8.5 Alternative methods . 23
4.8.6 Recording of tests . 23
4.8.7 Additional measurement . 23
4.8.8 Preliminary calculations . 23
4.8.9 Consistency and number of tests . 24
4.9 Repetition of acceptance tests . 24
4.10 Guidance on retrofit guarantees . 24
4.10.1 General . 24
4.10.2 Absolute guarantees . 25
4.10.3 Relative guarantees . 26
5 Measuring techniques and measuring instruments . 27
5.1 Overview. 27
5.1.1 Instrument accuracy requirements . 27
5.1.2 Measuring instruments. 27
5.1.3 Measuring uncertainty . 27
5.1.4 Calibration of instruments . 27
5.1.5 Alternative instrumentation . 27
5.1.6 Consistency of pre- and post-retrofit tests. 27
5.2 Measurement of power . 27
5.2.1 Determination of mechanical turbine output . 27
5.2.2 Measurement of boiler feed pump power . 27
5.2.3 Determination of electrical power of a turbine generator . 28
5.2.4 Measurement of electrical power . 28
5.2.5 Electrical instrument connections . 28
5.2.6 Electrical instruments . 28
5.2.7 Instrument transformers . 28
5.2.8 Determination of electrical power of pre- and post-retrofit tests . 28
5.3 Flow measurement . 28
5.3.1 Determination of flows to be measured . 28
5.3.2 Measurement of primary flow . 29
5.3.3 Installation and location of flow measuring devices . 29
5.3.4 Calibration of primary flow devices for water flow . 29
5.3.5 Inspection of flow measuring devices . 29
5.3.6 Differential pressure measurements. 30
5.3.7 Water flow fluctuation . 30
5.3.8 Secondary flow measurements . 30
5.3.9 Occasional secondary flows . 31
5.3.10 Density of water and steam . 31
5.3.11 Determination of cooling water flow of condenser . 31
5.4 Pressure measurement (excluding condensing turbine exhaust pressure) . 31
5.4.1 Pressures to be measured . 31
5.4.2 Instruments . 31
5.4.3 Main pressure measurements . 31
5.4.4 Pressure tapping holes and connecting lines . 31
5.4.5 Shut-off valves. 32

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5.4.6 Calibration of pressure measuring devices. 32
5.4.7 Atmospheric pressure . 32
5.4.8 Correction of readings . 32
5.5 Condensing turbine exhaust pressure measurement . 32
5.5.1 General . 32
5.5.2 Plane of measurement . 32
5.5.3 Pressure taps . 32
5.5.4 Manifolds . 32
5.5.5 Connecting lines . 32
5.5.6 Instruments . 32
5.5.7 Calibration . 32
5.6 Temperature measurement . 33
5.6.1 Points of temperature measurement . 33
5.6.2 Instruments . 33
5.6.3 Main temperature measurements . 33
5.6.4 Feed train temperature measurements (including bled steam) . 33
5.6.5 Condenser cooling water temperature measurement . 33
5.6.6 Thermometer wells . 33
5.6.7 Precautions to be observed in the measurement of temperature . 33
5.7 Steam quality determination . 33
5.7.1 General . 33
5.7.2 Tracer technique. 33
5.7.3 Condensing method . 33
5.7.4 Constant rate injection method . 33
5.7.5 Extraction enthalpy determined by constant rate injection method . 33
5.7.6 Tracers and their use . 34
5.7.7 Use of tracer techniques in retrofit applications . 34
5.8 Time measurement . 34
5.9 Speed measurement . 34
6 Evaluation of tests . 34
6.1 Preparation of evaluation . 34
6.2 Computation of results . 35
6.2.1 Calculation of average values of instrument readings . 35
6.2.2 Correction and conversion of averaged readings . 35
6.2.3 Checking of measured data . 35
6.2.4 Thermodynamic properties of steam and water . 36
6.2.5 Calculation of test results . 36
7 Corrections of test results and comparison with guarantee . 39
7.1 Guarantee values and guarantee conditions . 39
7.1.1 Guarantee values and guarantee conditions specific to retrofits . 39
7.2 Correction of initial steam flow capacity . 40
7.3 Correction of output . 40
7.3.1 Correction of maximum output . 40
7.3.2 Correction of Output with specified initial steam flow . 40
7.4 Correction of the thermal performance . 40
7.5 Definition and application of correction values . 40
7.6 Correction methods . 40
7.6.1 General . 40
7.6.2 Correction by heat balance calculation . 40

IEC 60953-3:2022 © IEC 2022 – 5 –
7.6.3 Correction by use of correction curves prepared by the manufacturer . 41
7.6.4 Tests to determine correction values . 41
7.7 Variables to be considered in the correction of specific turbine cycles. 41
7.7.1 Scope of corrections . 41
7.7.2 Turbines with regenerative feed-water heating . 41
7.7.3 Turbines which have no provision for the addition or extraction of steam
after partial expansion . 41
7.7.4 Turbines with steam extraction for purposes other than feed-water
heating (extraction turbines) . 41
7.7.5 Other types of turbine . 41
7.8 Guarantee comparison . 41
7.8.1 Tolerance and weighting . 41
7.8.2 Guarantee comparison with locus curve . 41
7.8.3 Guarantee comparison with guarantee point . 41
7.8.4 Guarantee comparison for turbines with throttle governing. 41
7.8.5 Guarantee comparison for extraction turbines . 41
7.8.6 Additional consideration for retrofit guarantee comparison . 42
7.9 Deterioration of turbine performance (ageing) . 42
7.9.1 Timing to minimise deterioration . 42
7.9.2 Correction with comparison tests . 42
7.9.3 Correction without comparison tests . 42
7.9.4 Deterioration of performance of retrofitted components . 42
8 Measuring uncertainty . 43
8.1 General . 43
8.2 Determination of measuring uncertainty of steam and water properties . 43
8.2.1 Pressure . 43
8.2.2 Temperature . 43
8.2.3 Enthalpy and enthalpy difference . 43
8.3 Calculation of measuring uncertainty of output . 43
8.3.1 Electrical measurement . 43
8.3.2 Mechanical measurement . 43
8.3.3 Additional uncertainty allowance because of unsteady load conditions . 43
8.4 Determination of measuring uncertainty of mass flow . 44
8.4.1 Measuring uncertainty of mass flow measurements . 44
8.4.2 Measuring uncertainty of multiple measurements of primary flow . 44
8.4.3 Uncertainty allowance for cycle imperfections . 44
8.5 Calculation of measuring uncertainty of results . 44
8.5.1 General . 44
8.5.2 Measuring uncertainty of thermal efficiency . 44
8.5.3 Measuring uncertainty of thermodynamic efficiency . 44
8.5.4 Uncertainty of corrections . 44
8.5.5 Guiding values for the measuring uncertainty of results . 44
8.6 Example uncertainty calculation . 44
Annex A (normative) Feedwater heater leakage and condenser leakage tests . 45
A.1 Feedwater heater leakage tests . 45
A.2 Condenser leakage tests . 45
Annex B (normative) Evaluation of multiple measurements, compatibility . 46
Annex C (normative) Mass flow balances . 47
C.1 General . 47

– 6 – IEC 60953-3:2022 © IEC 2022
C.2 Flows for further evaluations (informative) . 47
Annex D (informative) Short-statistical definition of measuring uncertainty and error
propagation in acceptance test . 48
Annex E (informative) Temperature variation method . 49
E.1 Description of the problem . 49
E.2 Possibility to determine the leakage flow . 49
E.3 Applied example . 49
Annex F (normative) Measuring uncertainty of results – retrofit application . 50
Annex G (informative) Retrofit improvement calculation – numerical examples (fossil
and nuclear) . 53
G.1 General . 53
G.2 Example of retrofitting a fossil-fired reheat turbine . 53
G.2.1 General . 53
G.2.2 HP cylinder retrofitting . 57
G.2.3 LP cylinder retrofitting with relative guarantee on heat rate(treated

separately from the HP case) . 58
G.2.4 Effect of retrofit on associated plant performance . 59
G.3 Example of retrofitting a nuclear turbine . 65
G.3.1 General . 65
G.3.2 Retrofit scenario and testing procedure . 66
G.3.3 Correction curves . 66
G.3.4 Application of correction curves . 67
G.3.5 Comparison of the measured values to the guarantees . 69
Annex H (informative) Uncertainty calculation – numerical examples (fossil and
nuclear) . 78
H.1 General . 78
H.2 Fossil case study . 78
H.2.1 General . 78
H.2.2 Evaluation . 79
H.3 Nuclear case study . 90
H.3.1 General . 90
H.3.2 Evaluation . 90

Figure 1 – Isentropic efficiency of the HP cylinder . 17
Figure 2 – LP turbine expansion line . 18
Figure G.1 – HP cylinder expansion . 54
Figure G.2 – LP cylinder expansion . 55
Figure G.3 – Original heat balance diagram (or base line) . 60
Figure G.4 – Correction curves . 61
Figure G.5 – Pre-retrofit test . 62
Figure G.6 – Pre-retrofit test: HP cylinder replaced . 63
Figure G.7 – Pre-retrofit test: LP cylinder replaced . 64
Figure G.8 – Leaving loss curve . 65
Figure G.9 – Correction curve of heat rate due to live steam pressure . 70
Figure G.10 – Correction curve of heat rate due to thermal power. 71
Figure G.11 – Correction curve of heat rate due to exhaust pressure . 71
Figure G.12 – Correction curve of heat rate due to quality of live steam . 72

IEC 60953-3:2022 © IEC 2022 – 7 –
Figure G.13 – Correction curve of heat rate for Δp of the moisture separator/reheaters . 72
Figure G.14 – Correction curve of heat rate due to temperature of the reheat steam . 73
Figure G.15 – Correction curve of heat rate due to quality of steam after the moisture
separator . 73
Figure G.16 – Curve of live steam pressure before the valves of the turbine as a

function of thermal power . 74
Figure G.17 – Baseline heat balance . 75
Figure G.18 – Guarantee heat balance . 76
Figure G.19 – Post-retrofit test re-calculated heat balance . 77
Figure H.1 – Instrumentation for a fossil plant . 81
Figure H.2 – Instrumentation for a nuclear plant . 92

Table 1 – Maximum deviations and fluctuations in operating conditions from specified
and relative data . 21
Table 2 – Guarantee alternatives . 25
Table 3 – Apportionment of unaccounted leakages . 36
Table 4 – Typical effects of cylinder efficiency on heat rate. 43
Table G.1 – Main parameters of the heat balances (Figure G.17 to Figure G.19) . 68
Table G.2 – Comparison between guaranteed and post-test re-calculated heat balance . 68
Table G.3 – Measured and corresponding calculated values from the post-test . 69
Table G.4 – Corrections due to differences between measured and calculated values
(from post re-calculated heat balance, Figure G.19) . 69
Table G.5 – Summary of corrections . 70
Table H.1 – Assumed total measured variable uncertainty for pressure, temperature
and generator output. 78
Table H.2 – Uncertainty percentage of calculated results at different flow

measurement uncertainty levels for a fossil plant . 80
Table H.3 – Uncertainty percentage of calculated results at different correlation levels
for a fossil plant . 80
Table H.4 – Heat Rate uncertainty of a fossil plant . 82
Table H.5 – HP isentropic efficiency uncertainty of a fossil plant . 84
Table H.6 – IP isentropic efficiency uncertainty of a fossil plant . 86
Table H.7 – LP isentropic efficiency uncertainty of a fossil plant . 88
Table H.8 – Uncertainty percentage of calculated results at different flow
measurement uncertainty levels for a nuclear plant . 91
Table H.9 – Uncertainty percentage of calculated results at different correlation levels

for a nuclear plant . 91
Table H.10 – Heat Rate uncertainty of a nuclear plant . 93
Table H.11 – HP isentropic efficiency uncertainty of a nuclear plant . 95
Table H.12 – LP isentropic efficiency uncertainty of a nuclear plant . 97

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INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
RULES FOR STEAM TURBINE THERMAL ACCEPTANCE TESTS –

Part 3: Thermal performance verification tests
of retrofitted steam turbines
FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
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8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
indispensable for the correct application of this publication.
9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of patent
rights. IEC shall not be held responsible for identifying any or all such patent rights.
IEC 60953-3 has been prepared by subcommittee WG11/MT14: Thermal Acceptance Test, of
IEC technical committee 5: Steam turbines. It is an International Standard.
This second edition cancels and replaces the first edition published in 2001. This edition
constitutes a technical revision.
This edition includes the following significant technical changes with respect to the previous
edition:
a) The Reference Standard has changed from IEC 60953-2 to IEC 60953-0 and therefore all
changes made in IEC 60953-0 are relevant to this revised Supplementary Standard;
b) Further detailed guidance is given for guarantee types in Clause 4.10;
c) Annex H – Measuring uncertainty of results has been revised to more closely align with the
ISO/IEC Guide 98: Uncertainty of measurement;
d) Annex K – Tracer technique has been deleted;
e) Annex L – Temperature variation method has been moved to IEC 60953-0.

IEC 60953-3:2022 © IEC 2022 – 9 –
The text of this International Standard is based on the following documents:
Draft Report on voting
5/249/FDIS 5/252/RVD
Full information on the voting for its approval can be found in the report on voting indicated in
the above table.
The language used for the development of this International Standard is English.
This part of IEC 60953 is to be read in conjunction with IEC 60953-0, and the words 'verification
test' are to be read in place of 'acceptance test'. IEC 60953-0 is taken as a Reference Standard.
A list of all parts in the IEC 60953 series, published under the general title Rules for steam
turbine thermal acceptance tests, can be found on the IEC website.
This document was drafted in accordance with ISO/IEC Directives, Part 2, and developed in
accordance with ISO/IEC Directives, Part 1 and ISO/IEC Directives, IEC Supplement, available
at www.iec.ch/members_experts/refdocs. The main document types developed by IEC are
described in greater detail at www.iec.ch/standardsdev/publications.
The committee has decided that the contents of this document will remain unchanged until the
stability date indicated on the IEC website under webstore.iec.ch in the data related to the
specific document. At this date, the document will be
• reconfirmed,
• wit
...