Condition monitoring and diagnostics of machines — Vibration condition monitoring — Part 4: Diagnostic techniques for gas and steam turbines with fluid-film bearings

This document sets out guidelines for the specific procedures to be considered when carrying out vibration diagnostics of various types of gas and steam turbines with fluid-film bearings. This document is intended to be used by condition monitoring practitioners, engineers and technicians and provides a practical step-by-step vibration-based approach to fault diagnosis. In addition, it gives examples for a range of machine and component types and their associated fault symptoms. The approach given in this document is based on established good practice, put together by experienced users, although it is acknowledged that other approaches can exist. Recommended actions for a particular diagnosis depend on individual circumstances, the degree of confidence in the fault diagnosis (e.g. has the same diagnosis been made correctly before for this machine), the experience of the practitioner, the fault type and severity as well as on safety and commercial considerations. It is neither possible nor the aim of this document to recommend actions for all circumstances.

Surveillance et diagnostic d'état des machines — Surveillance des vibrations — Partie 4: Techniques de diagnostic pour turbines à gaz et turbines à vapeur à paliers à film fluide

Le présent document établit des lignes directrices pour les procédures spécifiques qu’il convient de prendre en compte pour les diagnostics de vibration des différents types de turbines à gaz et turbines à vapeur à paliers à film fluide. Le présent document est destiné à être utilisé par les professionnels, les ingénieurs et les techniciens de la surveillance des machines et fournit une approche pratique, étape par étape, basée sur les vibrations pour le diagnostic des défauts. Il donne également des exemples pour toute une gamme de machines et de types de composants ainsi que les symptômes de défauts qui leur sont associés. L’approche fournie dans le présent document repose sur une bonne pratique, établie, mise en commun par des utilisateurs expérimentés, même s’il est admis que d'autres approches peuvent exister. Les actions recommandées pour un diagnostic particulier dépendent des circonstances individuelles, du degré de confiance dans le diagnostic de défauts (par exemple le même diagnostic a-t-il été correctement établi auparavant pour cette machine?), de l'expérience du professionnel, du type de défaut et de sa gravité ainsi que des considérations de sécurité et commerciales. Il n'est pas possible de recommander des actions pour tous les cas et ce n'est pas le but visé par le présent document.

General Information

Status
Published
Publication Date
22-Nov-2021
Current Stage
6060 - International Standard published
Start Date
23-Nov-2021
Due Date
31-Oct-2021
Completion Date
23-Nov-2021
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INTERNATIONAL ISO
STANDARD 13373-4
First edition
2021-11
Condition monitoring and diagnostics
of machines — Vibration condition
monitoring —
Part 4:
Diagnostic techniques for gas and
steam turbines with fluid-film
bearings
Surveillance et diagnostic d'état des machines — Surveillance des
vibrations —
Partie 4: Techniques de diagnostic pour turbines à gaz et turbines à
vapeur à paliers à film fluide
Reference number
ISO 13373-4:2021(E)
© ISO 2021

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ISO 13373-4:2021(E)
COPYRIGHT PROTECTED DOCUMENT
© ISO 2021
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
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CH-1214 Vernier, Geneva
Phone: +41 22 749 01 11
Email: copyright@iso.org
Website: www.iso.org
Published in Switzerland
ii
  © ISO 2021 – All rights reserved

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ISO 13373-4:2021(E)
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Measurements .2
4.1 Vibration measurements . 2
4.2 Machine operational parameter measurement . 2
5 Initial analysis .2
6 Specific analysis of gas and steam turbines with fluid-film bearings .3
7 Considerations when recommending actions . 3
Annex A (normative) Systematic approach for vibration analysis of gas and steam turbines
with fluid-film bearings .4
Annex B (informative) Methodology for diagnosing vibration problems of gas and steam
turbines with fluid-film bearings .13
Annex C (informative) Examples of vibration problems in steam turbines with fluid-film
bearings .18
Bibliography .22
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ISO 13373-4:2021(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 108, Mechanical vibration, shock and
condition monitoring, Subcommittee SC 2, Measurement and evaluation of mechanical vibration and shock
as applied to machines, vehicles and structures.
A list of all parts in the ISO 13373 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.
iv
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ISO 13373-4:2021(E)
Introduction
This document provides guidelines for the procedures to be considered when carrying out vibration
diagnostics of gas turbines and steam turbines on fluid-film bearings. It is intended to be used by
vibration practitioners, engineers and technicians and it provides them with useful diagnostic tools.
These tools include the use of diagnostic flowcharts, process tables, fault tables and symptom tables.
The material contained in this document presents the most basic, logical, and intelligent steps that
should be taken when diagnosing problems associated with these particular types of machines.
The ISO 20816 series of standards contains acceptable vibration magnitudes and zones for various
types and sizes of machines, ranging from new and well-running machines to machines that are in
danger of failing.
ISO 13373-1 presents the basic procedures for vibration narrow-band signal analysis. It includes the
types of transducers used, their ranges and their recommended locations on various types of machines,
on-line and periodic vibration monitoring systems, and potential machinery problems.
ISO 13373-2 includes descriptions of the signal conditioning equipment that is required; time and
frequency domain techniques; and the waveforms and signatures that represent the most common
machinery operating phenomena or machinery faults that are encountered when performing vibration
signature analysis.
ISO 13373-3 provides some procedures to determine the causes of vibration problems common to all
types of rotating machines. It includes: systematic approaches to characterize vibration effects; the
diagnostic tools available; which tools are needed for particular applications; and recommendations
on how the tools are to be applied to different machine types and components. However, this does not
preclude the use of other diagnostic techniques.
It should be noted that ISO 17359 indicates that diagnostics can be
— started as a succeeding activity after detection of an anomaly during monitoring, or
— executed synchronous with monitoring from the beginning.
This document considers only the former in which diagnostics is performed after an anomaly has been
detected. Moreover, this document focusses mainly on the use of flowcharts and process tables as
diagnostic tools, as well as fault tables and symptom tables, since it is felt that these are the tools that
are most appropriate for use by practitioners, engineers and technicians in the field.
The flowchart and diagnostic process table methodology presents a structured procedure for a person
in the field to diagnose a fault and find its cause. This step-by-step procedure should be able to guide
the practitioner in the vibration diagnostics of the machine anomaly, in order to reach the probable root
cause of this anomaly.
The fault tables present a list of the most common faults in machinery, as well as their manifestations in
the machine and vibration data. The symptom tables contain the main distinguishing vibration features
of the main faults. When used with the flowcharts, the tables assist with the identification of machinery
faults.
When approaching a machinery problem that manifests itself as a high or erratic vibration signal, the
diagnosis of the problem should be done in a well thought out, systematic manner. This document and
ISO 13373-3 achieve that purpose by providing to the analyst guidance on the selection of the proper
measuring tools, the analysis tools and their use, and the step-by-step recommended procedures for the
diagnosis of problems associated with various types of gas and steam turbines with fluid-film bearings.
VDI 3839-4 provides typical vibration patterns in steam and gas turbines, and can be a useful reference.
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INTERNATIONAL STANDARD ISO 13373-4:2021(E)
Condition monitoring and diagnostics of machines —
Vibration condition monitoring —
Part 4:
Diagnostic techniques for gas and steam turbines with
fluid-film bearings
1 Scope
This document sets out guidelines for the specific procedures to be considered when carrying out
vibration diagnostics of various types of gas and steam turbines with fluid-film bearings.
This document is intended to be used by condition monitoring practitioners, engineers and technicians
and provides a practical step-by-step vibration-based approach to fault diagnosis. In addition, it gives
examples for a range of machine and component types and their associated fault symptoms.
The approach given in this document is based on established good practice, put together by
experienced users, although it is acknowledged that other approaches can exist. Recommended actions
for a particular diagnosis depend on individual circumstances, the degree of confidence in the fault
diagnosis (e.g. has the same diagnosis been made correctly before for this machine), the experience of
the practitioner, the fault type and severity as well as on safety and commercial considerations. It is
neither possible nor the aim of this document to recommend actions for all circumstances.
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.
ISO 2041, Mechanical vibration, shock and condition monitoring — Vocabulary
ISO 13372, Condition monitoring and diagnostics of machines — Vocabulary
ISO 13373-1, Condition monitoring and diagnostics of machines — Vibration condition monitoring —
Part 1: General procedures
ISO 13373-2, Condition monitoring and diagnostics of machines — Vibration condition monitoring —
Part 2: Processing, analysis and presentation of vibration data
ISO 13373-3:2015, Condition monitoring and diagnostics of machines — Vibration condition monitoring —
Part 3: Guidelines for vibration diagnosis
ISO 21940-2, Mechanical vibration — Rotor balancing — Part 2: Vocabulary
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 2041, ISO 13372 and
ISO 21940-2 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
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ISO 13373-4:2021(E)
— IEC Electropedia: available at https:// www .electropedia .org/
4 Measurements
4.1 Vibration measurements
Vibration measurements may be obtained using two main categories of transducers:
a) non-contacting, e.g. inductive, capacitive and eddy current probes used on rotating shafts;
b) seismic transducers, e.g. accelerometers or velocity transducers used on non-rotating parts, such
as bearing housings.
International Standards have been written to help in assessing the vibration severity for both of these
types of measurements, for instance the ISO 7919 series, the ISO 10816 series and the ISO 20816 series.
Guidance for the selection of the appropriate International Standard to use is given in ISO/TR 19201.
It is important to recognize that the appropriate transducer, signal conditioning, measurement and
analysis system should be used for the diagnosis of faults considering specific situations in gas and
steam turbines with fluid-film bearings. Before any measurements are taken, it is good practice to
consider whether the grounding and electrical fields of the machine will have any effect on them.
Descriptions of transducers, measurement systems and analysis techniques are given in ISO 13373-1
and ISO 13373-2, which shall be considered for appropriate selection.
4.2 Machine operational parameter measurement
Operational parameters [e.g. rotational speed, load, mounting configuration (rigid or flexible support
arrangement) and temperature], that can have an influence on machine vibration characteristics are
important in order to arrive at an appropriate fault diagnosis. For a given machine, these parameters
can be associated with a range of steady-state and transient operating conditions.
5 Initial analysis
An initial fault analysis shall be performed using the guidelines given in ISO 13373-3:2015, Annex A and
shall identify any safety concerns such as the
a) presence and severity of any high vibration,
b) past history of the machine,
c) effects of the machine operating parameters,
d) consequence of not taking any necessary corrective action to reduce machine vibration, and
e) shutting the turbine down to prevent damage.
In addition, other factors such as the
f) measurement transducer mounting configuration,
g) effect of any nearby rotating machines, and
h) effect of the building and the machine foundation [e.g. platform foundation (onshore and offshore)
environment] on the machine under consideration should be taken into account during the initial
analysis of machine performance.
Also see ISO 13373-3:2015, Annexes B to D for a description of some common machine faults (e.g.
installation and bearing defects).
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ISO 13373-4:2021(E)
6 Specific analysis of gas and steam turbines with fluid-film bearings
The systematic procedure used in the ISO 13373 series includes usage of fault tables, symptom tables
and a step-by-step methodology of vibration diagnosis of faults. For this document, the fault table
for the diagnosis of gas and steam turbines with fluid-film bearings to be used is given by Table A.1,
the symptom table is given in Table A.2, while the methodology of vibration diagnosis is presented
in Annex B. Examples of the use of the fault table, symptom table and methodology of vibration
diagnosis of gas and steam turbines with fluid-film bearings are given in Annex C. Note that these
annexes do not cover turbine vibration from hydrodynamic bearing problems which are addressed in
ISO 13373-3:2015, Annex C.
This approach is considered to be good practice put together by experienced users, although it is
acknowledged that other approaches can exist.
It should be noted that in some cases the vibration diagnosis can point to several root causes and it is
recommended that an expert is consulted in order to establish the most probable fault.
7 Considerations when recommending actions
A number of factors influence any remedial or corrective actions to be taken, such as
a) their safety,
b) commercial considerations,
c) incorrect machine design, and
d) machine assembly issues.
Clearly, the appropriate action(s) for a particular diagnosis depend(s) on individual circumstances and
it is beyond the scope of this document to make specific recommendations. Nevertheless, it is important
to consider possible actions resulting from the diagnosis and the implications of those actions.
Recommended actions depend on the degree of confidence in the fault diagnosis (e.g. has the same
diagnosis been made correctly before for this machine?), the fault type and severity as well as on safety
and commercial considerations. It is neither possible nor the aim of this document to recommend
actions for all circumstances.
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ISO 13373-4:2021(E)
Annex A
(normative)

Systematic approach for vibration analysis of gas and steam
turbines with fluid-film bearings
A systematic approach to vibration analysis of gas and steam turbines with fluid-film bearings is given
by the fault table in Table A.1, and the symptom table given in Table A.2. The information included in
Table A.1 is not intended to be exhaustive, but includes the most prevalent faults associated with steam
and gas turbines with fluid film bearings.
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ISO 13373-4:2021(E)
5
© ISO 2021 – All rights reserved

Table A.1 — Fault table for vibration analysis of gas and steam turbines with fluid-film bearings
Conditions Initial rate Major frequency Subsequent
under which the of change of component of behaviour Effect on reso- Behaviour on
Fault Repeatability Comments
vibration change vibration am- changed vibra- of vibration nance speed barring
occurs plitude tion amplitude with time
Immediately
Shaft unbalance Steady state 1x Steady None Not affected Repeatable None
evident
For turbines consist-
ing of multiple rotors
Shaft unbalance in tandem, the larg-
resulting from Usually steady Step change Steady fol- Vibration level Rubbing can est changes usually
rotating com- state but can be or series of 1x lowing step significantly be heard in ex- None occur at the bearings
ponent material transient changes change changed treme cases of the affected rotor.
loss Rotor unbalance
may be due to blade
erosion.
Reversal of transient
will not immediately
May increase reverse the vibration
or decrease change. Correlate
depending on Trends, but with bearing wedge
Under steady whether the not necessari- pressures and metal
Predominantly
Slow, unless oil conditions a bearing eleva- ly amplitudes temperatures. This
Bearing eleva- Following opera- 1x. Less than 1x
whirl is pre- new steady tion is raised None will tend to fault is typically
tion change tional transient can be exhibited
dominant level will be or lowered. repeat follow- limited to turbines
(see oil whirl)
reached Adjacent rotors ing similar with two bearings
may experience transients per rotor. Turbines
the opposite with a single bearing
effect per rotor tend to be
less susceptible to
this fault.
NOTES:
a) Light rubbing tends to occur between the shaft and the stationary seals, which are locations where the clearances are small by design and steps are taken by the manufacturer
in the design of the seals to minimise the effects of rubbing, e.g. through the use of spring-backed segmented seal rings and/or brass/bronze seal fins.
b) Hard rubbing tends to occur at other locations where rubbing is not generally intended to occur by design and therefore more substantial contact can occur.
c) The Morton effect refers to a vibration condition where viscous heating of the shaft surface occurs due to shearing of the oil in a narrow oil film of a fluid-film bearing, leading
to a temporary thermal bend of the shaft.

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ISO 13373-4:2021(E)
6
  © ISO 2021 – All rights reserved

Table A.1 (continued)
Conditions Initial rate Major frequency Subsequent
under which the of change of component of behaviour Effect on reso- Behaviour on
Fault Repeatability Comments
vibration change vibration am- changed vibra- of vibration nance speed barring
occurs plitude tion amplitude with time
Reduces with
speed reduc-
During or follow- tion, except
Slow roll run-
ing a transient, when pass-
Vibration level out will gener- With severe bends
Permanent bend large temper- Rapid – often ing through
1x significantly ally increase to Yes barring motor will
in the shaft ature drop or large resonance
changed a new, higher not engage.
change in rotor to speed. Will
steady level
casing position stabilize at
new steady
level
Will revert
Closely follows Slow roll run- Repeats at Can be caused by the
to previous
Transient bend temperature Vibration level out will decay to each start bi-metal effect and
During tempera- value follow-
in the shaft with change. De- 1x can be signifi- previous normal for the same differential emis-
ture change ing stabi-
no rubbing pends on rotor cantly changed level over a operating sivity of the shaft
lization of
construction period of time conditions materials.
temperature
Reversal of speed
1x, heavy contact, Slow roll can be
or load change will
apparent as flat higher imme-
Variable. If Cyclic Not necessar- restore previous
Speed or load spots on orbits, diately after
Transient bend rapid a perma- amplitude Vibration level ily repeatable vibration levels fairly
change. Station- might also cause rundown and
in the shaft with nent bend will with phase can be signifi- each time the quickly. Vector will
ary and rotating responses at will decay to
hard rubbing almost certainly rotation or cantly changed transient is rotate with a period
parts contact natural frequen- previous level
develop variation undergone of typically 1/2 h
cies and higher over a period of
to 3 h. Depends on
harmonics time
construction.
NOTES:
a) Light rubbing tends to occur between the shaft and the stationary seals, which are locations where the clearances are small by design and steps are taken by the manufacturer
in the design of the seals to minimise the effects of rubbing, e.g. through the use of spring-backed segmented seal rings and/or brass/bronze seal fins.
b) Hard rubbing tends to occur at other locations where rubbing is not generally intended to occur by design and therefore more substantial contact can occur.
c) The Morton effect refers to a vibration condition where viscous heating of the shaft surface occurs due to shearing of the oil in a narrow oil film of a fluid-film bearing, leading
to a temporary thermal bend of the shaft.

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ISO 13373-4:2021(E)
7
© ISO 2021 – All rights reserved

Table A.1 (continued)
Conditions Initial rate Major frequency Subsequent
under which the of change of component of behaviour Effect on reso- Behaviour on
Fault Repeatability Comments
vibration change vibration am- changed vibra- of vibration nance speed barring
occurs plitude tion amplitude with time
Increase clear-
ance (e.g. by rotor
1x periodic ampli- Typically
Slow roll run- alignment change)
tude and phase goes into a
out can be high- to eliminate rubbing.
change. Periodic- limit cycle.
er immediately Alternatively, reduce
Morton effect/ ity is dependent Howev- Vibration level
Steady speed after run-down Usually re- vibration to reduce
Newkirk effect Slowly develops on the severity of er, it can can be signifi-
conditions and will decay peatable effect. Can require
(light rubbing) the rub and can disappear cantly changed
to previous level balancing. Reduce
vary between temporarily
over a period of overhanging mass
minutes and sev- and then
time if present. Solution
eral hours reappear
can involve bearing
modification.
Predominantly
just less than Significant speed
Erratic
0,5x, for whip reduction required
at higher
Speed change or it locks at rotor to eliminate the
Oil whirl (or level than
during bearing Very rapid first resonance None Not present Will repeat increased vibration.
whip) normal and
unloading frequency de- Will repeat under
frequently
pending on rotor identical operating
unstable
design (rigid or conditions.
flexible)
Increase in steam
flow on load. Can
Load dependent.
also occur with
1x load depend- Will repeat Modify admission
Steam-induced bearing height
Often very rapid ent for concen- None None None until source is sequence; repair dia-
vibration change. Occurs
tricity problems corrected phragms; install noz-
in HP or HP-IP
zle blocks properly.
steam turbine
cylinders
NOTES:
a) Light rubbing tends to occur between the shaft and the stationary seals, which are locations where the clearances are small by design and steps are taken by the manufacturer
in the design of the seals to minimise the effects of rubbing, e.g. through the use of spring-backed segmented seal rings and/or brass/bronze seal fins.
b) Hard rubbing tends to occur at other locations where rubbing is not generally intended to occur by design and therefore more substantial contact can occur.
c) The Morton effect refers to a vibration condition where viscous heating of the shaft surface occurs due to shearing of the oil in a narrow oil film of a fluid-film bearing, leading
to a temporary thermal bend of the shaft.

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ISO 13373-4:2021(E)
8
  © ISO 2021 – All rights reserved

Table A.1 (continued)
Conditions Initial rate Major frequency Subsequent
under which the of change of component of behaviour Effect on reso- Behaviour on
Fault Repeatability Comments
vibration change vibration am- changed vibra- of vibration nance speed barring
occurs plitude tion amplitude with time
Return to steam flow
below original will
Increase in steam
immediately reverse
flow on load. Can Subsynchro-
the vibration change.
also occur with nous – normally Will repeat
However, it should
bearing height at frequency of during similar
Steam whirl Often very rapid None None None be noted that there
change. Occurs resonance speed steam flow
is often a hyster-
in HP or HP-IP of the rotor in increases
esis effect which
steam turbine question
requires the steam
cylinders
flow reduction to be
significant.
Vibration
will remain
Flow – Pressure high unless Will repeat Return to appropri-
Rotating stall
conditions. Stall Violent and very there is a during similar ate flow will imme-
in gas turbine Subsynchronous None None
is separation of rapid change in flow condi- diately reverse the
compressors
flow on airfoil speed or tions vibration change.
inlet guide
vane position
Vibration
will remain
Compressor Flow – Pressure high unless Will repeat Return to appropri-
Subsynchronous
surge in gas tur- conditions. Surge Violent and very there is a during similar ate flow will imme-
– not a discrete None None
bine compres- is whole compres- rapid change in flow condi- diately reverse the
frequency
sors sor choking speed or tions vibration change.
inlet guide
vane position
NOTES:
a) Light rubbing tends to occur between the shaft and the stationary seals, which are locations where the clearances are small by design and steps are taken by the manufacturer
in the design of the seals to minimise the effects of rubbing, e.g. through the use of spring-backed segmented seal rings and/or brass/bronze seal fins.
b) Hard rubbing tends to occur at other locations where rubbing is not generally intended to occur by design and therefore more substantial contact can occur.
c) The Morton effect refers to a vibration condition where viscous heating of the shaft surface occurs due to shearing of the oil in a narrow oil film of a fluid-film bearing, leading
to a temporary thermal bend of the shaft.

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ISO 13373-4:2021(E)
9
© ISO 2021 – All rights reserved

Table A.1 (continued)
Conditions Initial rate Major frequency Subsequent
under which the of change of component
...

NORME ISO
INTERNATIONALE 13373-4
Première édition
2021-11
Surveillance et diagnostic d'état
des machines — Surveillance des
vibrations —
Partie 4:
Techniques de diagnostic pour
turbines à gaz et turbines à vapeur à
paliers à film fluide
Condition monitoring and diagnostics of machines — Vibration
condition monitoring —
Part 4: Diagnostic techniques for gas and steam turbines with fluid-
film bearings
Numéro de référence
ISO 13373-4:2021(F)
© ISO 2021

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ISO 13373-4:2021(F)
DOCUMENT PROTÉGÉ PAR COPYRIGHT
© ISO 2021
Tous droits réservés. Sauf prescription différente ou nécessité dans le contexte de sa mise en œuvre, aucune partie de cette
publication ne peut être reproduite ni utilisée sous quelque forme que ce soit et par aucun procédé, électronique ou mécanique,
y compris la photocopie, ou la diffusion sur l’internet ou sur un intranet, sans autorisation écrite préalable. Une autorisation peut
être demandée à l’ISO à l’adresse ci-après ou au comité membre de l’ISO dans le pays du demandeur.
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E-mail: copyright@iso.org
Web: www.iso.org
Publié en Suisse
ii
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ISO 13373-4:2021(F)
Sommaire Page
Avant-propos .iv
Introduction .v
1 Domaine d’application . 1
2 Références normatives .1
3 Termes et définitions . 1
4 Mesurages . 2
4.1 Mesurages des vibrations . 2
4.2 Mesurage des paramètres de fonctionnement des machines . 2
5 Analyse initiale . 2
6 Analyse spécifique des turbines à gaz et des turbines à vapeur à paliers à film fluide .3
7 Considérations lorsqu'on recommande des actions . 3
Annexe A (normative) Approche systématique pour l'analyse des vibrations des turbines à
gaz et des turbines à vapeur à paliers à film fluide . 4
Annexe B (informative) Méthodologie pour diagnostiquer les problèmes vibratoires des
turbines à gaz et des turbines à vapeur à paliers à film fluide .17
Annexe C (informative) Exemples de problèmes de vibrations des turbines à vapeur à
paliers à film fluide .23
Bibliographie .27
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ISO 13373-4:2021(F)
Avant-propos
L'ISO (Organisation internationale de normalisation) est une fédération mondiale d'organismes
nationaux de normalisation (comités membres de l'ISO). L'élaboration des Normes internationales est
en général confiée aux comités techniques de l'ISO. Chaque comité membre intéressé par une étude
a le droit de faire partie du comité technique créé à cet effet. Les organisations internationales,
gouvernementales et non gouvernementales, en liaison avec l'ISO participent également aux travaux.
L'ISO collabore étroitement avec la Commission électrotechnique internationale (IEC) en ce qui
concerne la normalisation électrotechnique.
Les procédures utilisées pour élaborer le présent document et celles destinées à sa mise à jour sont
décrites dans les Directives ISO/IEC, Partie 1. Il convient, en particulier de prendre note des différents
critères d'approbation requis pour les différents types de documents ISO. Le présent document
a été rédigé conformément aux règles de rédaction données dans les Directives ISO/IEC, Partie 2
(voir www.iso.org/directives).
L'attention est attirée sur le fait que certains des éléments du présent document peuvent faire l'objet de
droits de propriété intellectuelle ou de droits analogues. L'ISO ne saurait être tenue pour responsable
de ne pas avoir identifié de tels droits de propriété et averti de leur existence. Les détails concernant
les références aux droits de propriété intellectuelle ou autres droits analogues identifiés lors de
l'élaboration du document sont indiqués dans l'Introduction et/ou dans la liste des déclarations de
brevets reçues par l'ISO (voir www.iso.org/brevets).
Les appellations commerciales éventuellement mentionnées dans le présent document sont données
pour information, par souci de commodité, à l’intention des utilisateurs et ne sauraient constituer un
engagement.
Pour une explication de la nature volontaire des normes, la signification des termes et expressions
spécifiques de l'ISO liés à l'évaluation de la conformité, ou pour toute information au sujet de l'adhésion
de l'ISO aux principes de l’Organisation mondiale du commerce (OMC) concernant les obstacles
techniques au commerce (OTC), voir le lien suivant: www.iso.org/iso/fr/avant-propos.
Le présent document a été élaboré par le comité technique ISO/TC 108, Vibrations et chocs mécaniques,
et leur surveillance, sous-comité SC 2, Mesurage et évaluation des vibrations et chocs mécaniques appliqués
aux machines, aux véhicules et aux structures.
Une liste de toutes les parties de la série ISO 13373 se trouve sur le site web de l’ISO.
Il convient que l’utilisateur adresse tout retour d’information ou toute question concernant le présent
document à l’organisme national de normalisation de son pays. Une liste exhaustive desdits organismes
se trouve à l’adresse www.iso.org/members.html.
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ISO 13373-4:2021(F)
Introduction
Le présent document fournit des lignes directrices pour les procédures qu’il convient de prendre en
compte pour les diagnostics de vibration des turbines à gaz et turbines à vapeur à paliers à film fluide.
Il est destiné à être utilisé par les professionnels, les ingénieurs et les techniciens du domaine des
vibrations et il leur fournit des outils de diagnostic utiles. Ces outils de diagnostic utilisés comprennent
les organigrammes, les tableaux de processus, les tableaux de défauts et les tableaux de symptômes. Le
contenu du présent document présente les étapes les plus élémentaires, logiques et intelligentes qu’il
convient de prendre lors du diagnostic de problèmes associés à ces types de machines particulières.
La série de normes ISO 20816 contient les amplitudes et les zones de vibrations acceptables pour divers
types et tailles de machines, allant des nouvelles machines et des machines fonctionnant correctement
aux machines présentant des risques de défaillance.
L’ISO 13373-1 présente les procédures générales relatives à l’analyse des signaux des vibrations en bande
étroite. Elle inclut: les types de transducteurs utilisés, leurs gammes et leur emplacement recommandé
sur les différents types de machines, les systèmes de surveillance des vibrations périodiques et en ligne,
et les éventuels problèmes des machines.
L’ISO 13373-2 inclut la description du matériel de conditionnement des signaux requis, les techniques
relatives au domaine temporel et au domaine fréquentiel, et les formes d’onde et les signatures qui
représentent les phénomènes de fonctionnement des machines ou les défauts des machines rencontrés
lors de l’analyse des signatures vibratoires.
L’ISO 13373-3 fournit un certain nombre de procédures visant à établir les causes des problèmes de
vibrations communs à tous les types de machines tournantes. Elle inclut: des approches systématiques
pour caractériser les effets des vibrations, les outils de diagnostic disponibles, les outils requis pour
les applications particulières, et les recommandations relatifs à l'application des outils en fonction des
types de machines et des composants. Cela n'exclut toutefois pas le recours à d’autres techniques de
diagnostic.
Il convient de noter que l’ISO 17359 précise que les diagnostics peuvent être
— démarrés comme activité après détection d’une anomalie durant une surveillance, où
— mis en œuvre dès le début de façon synchrone avec le processus de surveillance.
Le présent document ne traite que le premier de ces cas, autrement dit, celui de diagnostics effectués
après détection d’une anomalie. Par ailleurs, le présent document traite essentiellement de l’utilisation
d’organigrammes et de tableaux de processus comme outils de diagnostic ainsi que des tableaux de
défauts et de symptômes car ce sont les outils jugés comme étant les plus appropriés pour une utilisation
par les professionnels, les ingénieurs et les techniciens sur le terrain.
La méthodologie relative aux organigrammes et des tableaux de processus de diagnostic présente une
procédure structurée permettant à une personne sur le terrain de diagnostiquer un défaut et d'en
trouver la cause. Il convient que cette procédure étape par étape puisse guider le professionnel dans son
diagnostic de vibrations relatifs à l'anomalie de la machine, pour trouver la cause originelle probable de
cette anomalie.
Les tableaux de défauts présentent une liste des défauts les plus communs des machines ainsi que
leurs manifestations au niveau de la machine et des données vibratoires. Les tableaux de symptômes
contiennent les principales caractéristiques vibratoires distinctives des principaux défauts. Lorsqu’ils
ont utilisé avec les organigrammes, les tableaux permettent d’identifier les défauts des machines.
Lorsqu’on traite un problème de machine qui se manifeste par un signal de vibration importante ou
erratique, il convient d'effectuer un diagnostic du problème de manière systématique et bien réfléchie.
Le présent document ainsi que l’ISO 13373-3 est conforme à cet objectif car il fournit à l'analyste des
recommandations relatives à la sélection des outils de mesure appropriés, les outils d'analyse et leur
utilisation, et les procédures étape par étape recommandées pour le diagnostic des problèmes associés
aux différents types de turbines à gaz et turbines à vapeur à paliers à film fluide.
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ISO 13373-4:2021(F)
Le VDI 3839-4, fournit des profils typiques de vibrations des turbines à gaz et turbines à vapeur et peut
constituer une référence utile.
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NORME INTERNATIONALE ISO 13373-4:2021(F)
Surveillance et diagnostic d'état des machines —
Surveillance des vibrations —
Partie 4:
Techniques de diagnostic pour turbines à gaz et turbines à
vapeur à paliers à film fluide
1 Domaine d’application
Le présent document établit des lignes directrices pour les procédures spécifiques qu’il convient de
prendre en compte pour les diagnostics de vibration des différents types de turbines à gaz et turbines
à vapeur à paliers à film fluide.
Le présent document est destiné à être utilisé par les professionnels, les ingénieurs et les techniciens de
la surveillance des machines et fournit une approche pratique, étape par étape, basée sur les vibrations
pour le diagnostic des défauts. Il donne également des exemples pour toute une gamme de machines et
de types de composants ainsi que les symptômes de défauts qui leur sont associés.
L’approche fournie dans le présent document repose sur une bonne pratique, établie, mise en commun
par des utilisateurs expérimentés, même s’il est admis que d'autres approches peuvent exister. Les
actions recommandées pour un diagnostic particulier dépendent des circonstances individuelles, du
degré de confiance dans le diagnostic de défauts (par exemple le même diagnostic a-t-il été correctement
établi auparavant pour cette machine?), de l'expérience du professionnel, du type de défaut et de sa
gravité ainsi que des considérations de sécurité et commerciales. Il n'est pas possible de recommander
des actions pour tous les cas et ce n'est pas le but visé par le présent document.
2 Références normatives
Les documents suivants sont cités dans le texte de sorte qu’ils constituent, pour tout ou partie de leur
contenu, des exigences du présent document. Pour les références datées, seule l'édition citée s'applique.
Pour les références non datées, la dernière édition du document de référence s'applique (y compris les
éventuels amendements).
ISO 2041, Vibrations et chocs mécaniques, et leur surveillance — Vocabulaire
ISO 13372, Surveillance et diagnostic de l'état des machines — Vocabulaire
ISO 13373-1, Surveillance et diagnostic d'état des machines — Surveillance des vibrations — Partie 1:
Procédures générales
ISO 13373-2, Surveillance et diagnostic d'état des machines — Surveillance des vibrations — Partie 2:
Traitement, analyse et présentation des données vibratoires
ISO 13373-3:2015, Surveillance et diagnostic d'état des machines — Surveillance des vibrations — Partie 3:
Lignes directrices pour le diagnostic des vibrations
ISO 21940-2, Vibrations mécaniques — Équilibrage des rotors — Partie 2: Vocabulaire
3 Termes et définitions
Pour les besoins du présent document, les termes et définitions donnés dans l'ISO 2041, ISO 13372 et
ISO 21940-2 s’appliquent.
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ISO 13373-4:2021(F)
L'ISO et l'IEC tiennent à jour des bases de données terminologiques destinées à être utilisées en
normalisation, consultables aux adresses suivantes:
— ISO Online browsing platform: disponible à l'adresse https:// www .iso .org/ obp
— IEC Electropedia: disponible à l'adresse https:// www .electropedia .org/
4 Mesurages
4.1 Mesurages des vibrations
On peut obtenir des mesurages des vibrations en utilisant deux catégories principales de transducteurs:
a) sans contact, par exemple, capteurs inductifs, capacitifs et à courant de Foucault utilisés sur les
arbres tournants;
b) transducteurs sismiques, par exemple, accéléromètres ou transducteurs de vitesse utilisés sur des
parties non tournantes, comme les logements de palier.
Des normes internationales ont été rédigées pour aider à évaluer la gravité des vibrations pour ces
deux types de mesures, par exemple les séries ISO 7919, ISO 10816 et ISO 20816 .
Des recommandations relatives au choix de la Norme internationale appropriée à utiliser sont données
dans l’ISO/TR 19201.
Il est important de comprendre qu'il convient d'utiliser le transducteur, le conditionnement des signaux,
le système de mesurage et d'analyse appropriés pour le diagnostic des défauts en tenant compte des
situations spécifiques aux turbines à gaz et turbines à vapeur à paliers à film fluide. Avant de prendre
des mesures, il est bon de se demander si la mise à la terre et les champs électriques de la machine
auront un effet sur celles-ci.
Les descriptions des transducteurs, des systèmes de mesure et des techniques d'analyse sont données
dans l’ISO 13373-1 et l’ISO 13373-2, qui doivent être prises en compte pour une sélection appropriée.
4.2 Mesurage des paramètres de fonctionnement des machines
L'acquisition des paramètres de fonctionnement [par exemple la vitesse de rotation, la charge, la
configuration du montage (dispositif de support rigide ou flexible) et la température], qui peuvent
exercer une influence sur les caractéristiques de vibrations d’une machine, est importante pour
parvenir un diagnostic approprié des défauts. Pour une machine donnée, ces paramètres peuvent être
associés à une série de conditions de régime établi et transitoire.
5 Analyse initiale
Une analyse initiale des défauts doit être effectuée en utilisant les lignes directrices données dans
l’ISO 13373-3:2015, Annexe A et doit permettre d'identifier tout problèmes de sécurité tels que
a) la présence et la gravité de toute vibration élevée,
b) l'historique de la machine,
c) les effets des paramètres de fonctionnement de la machine,
d) les conséquences de l’absence de mesures correctives pour réduire les vibrations de la machine, et
e) l'arrêt de la turbine pour éviter les dommages.
En outre, d'autres facteurs tels que
f) la configuration de montage du transducteur de mesure,
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ISO 13373-4:2021(F)
g) l’effet de toute machine tournante à proximité, et
h) l'effet de l'environnement du bâtiment et de la fondation de la machine [par exemple la fondation de
la plate-forme (à terre et en mer)]. Il convient de prendre ces éléments en compte lors de l'analyse
initiale des performances de la machine sur la machine considérée.
Voir également l’ISO 13373-3:2015, Annexes B à D, pour une description de certains défauts communs
des machines (par exemple, les défauts d'installation et les défauts de paliers).
6 Analyse spécifique des turbines à gaz et des turbines à vapeur à paliers à film
fluide
La procédure systématique utilisée dans la série ISO 13373 comprend l'utilisation de tableaux de
défauts, de tableaux de symptômes et une méthodologie étape par étape de diagnostic vibratoire des
défauts. Pour le présent document, le tableau de défauts pour le diagnostic des turbines à gaz et à
vapeur à paliers à film fluide à utiliser est donné par le Tableau A.1, le tableau de symptômes est donné
dans le Tableau A.2, tandis que la méthodologie de diagnostic vibratoire est présentée dans l'Annexe B.
Des exemples d'utilisation du tableau des défauts, du tableau des symptômes et de la méthodologie de
diagnostic vibratoire des turbines à gaz et à vapeur à paliers à film fluide sont indiqués dans l'Annexe C.
Notez que ces annexes ne couvrent pas les vibrations de la turbine dues à des problèmes de paliers
hydrodynamiques, qui sont traités dans l’ISO 13373-3:2015, Annexe C.
On considère que cette approche constitue une bonne pratique établie par des utilisateurs expérimentés,
bien qu'il soit reconnu que d'autres approches puissent exister.
Il convient de noter que dans certains cas, le diagnostic vibratoire peut indiquer plusieurs causes
originelles et qu’il est recommandé de consulter un expert afin d'établir le défaut le plus probable.
7 Considérations lorsqu'on recommande des actions
Un certain nombre de facteurs influencent les remèdes ou les actions correctives à prendre, tels que
a) leur sécurité,
b) les considérations commerciales,
c) conception incorrecte de la machine, et
d) les problèmes d'assemblage de la machine.
La ou les actions appropriée(s) pour un diagnostic particulier dépendent clairement des circonstances
individuelles, et la formulation de recommandations spécifiques ne relève pas du domaine d'application
du présent document. Néanmoins, il est important d'envisager les actions possibles résultant du
diagnostic et les implications de ces actions.
Les actions recommandées dépendent du degré de confiance dans le diagnostic de défaut (par exemple
le même diagnostic a-t-il été établi correctement auparavant pour cette machine?), du type de défaut
et de sa gravité ainsi que des considérations de sécurité et commerciales. Il n'est pas possible de
recommander des actions pour tous les cas et ce n'est pas le but visé par le présent document.
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ISO 13373-4:2021(F)
Annexe A
(normative)

Approche systématique pour l'analyse des vibrations des turbines
à gaz et des turbines à vapeur à paliers à film fluide
Une approche systématique de l'analyse des vibrations des turbines à gaz et des turbines à vapeur
à paliers à film fluide est donnée par le tableau des défauts dans le Tableau A.1 et par le tableau des
symptômes dans le Tableau A.2. Les informations incluses dans le Tableau A.1 n’ont pas pour objectif
d’être exhaustives, mais elles incluent les défauts les plus courants associés aux turbines à gaz et aux
turbines à vapeur à paliers à film fluide.
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ISO 13373-4:2021(F)
5
© ISO 2021 – Tous droits réservés

Tableau A.1 — Tableau des défauts pour l'analyse des vibrations des turbines à gaz et des turbines à vapeur à paliers à film fluide
Composante Compor-
Vitesse initiale
Conditions de fréquence tement
de modifi- Effet sur la
entraînant la principale de ultérieur de Comportement
Défaut cation de vitesse de réso- Répétabilité Commentaires
modification l'amplitude de la vibra- sur le vireur
l'amplitude nance
des vibrations vibration modi- tion avec le
des vibrations
fiée temps
Déséquilibre de Régime perma- Immédiatement
1x Stable Aucun Non affecté Répétable Aucun
l'arbre nent évident
Pour les turbines
composées de
plusieurs rotors
en tandem, les
Déséquilibre de
changements les
l'arbre résul- État générale- Un frottement
Changement Stable après Niveau de vibra- plus importants
tant de la perte ment stable mais est parfois en-
d'étape ou série 1x changement tion significative- Aucun se produisent
matérielle d'un peut être transi- tendu dans les
de changements d'étape ment modifié généralement au
composant tour- toire cas extrêmes
niveau des paliers du
nant
rotor concerné. Le
déséquilibre du rotor
peut être dû à une
érosion des aubes.
NOTES:
a) Un léger frottement a tendance à se produire entre l'arbre et les joints stationnaires, qui sont des endroits où les jeux sont réduits par conception et où des mesures sont prises
par le fabricant dans la conception des joints pour minimiser les effets du frottement, par exemple en utilisant des bagues d'étanchéité segmentées à ressort et/ou des ailettes
d'étanchéité en laiton/bronze.
b) Le frottement dur a tendance à se produire à d'autres endroits où le frottement n'est généralement pas prévu par la conception et où un contact plus important peut donc se
produire.
c) L'effet Morton désigne une condition de vibration dans laquelle un réchauffement visqueux de la surface de l'arbre se produit en raison du cisaillement de l'huile dans un film
d'huile étroit d'un palier à film fluide, ce qui entraîne une courbure thermique temporaire de l'arbre.

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ISO 13373-4:2021(F)
6
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Tableau A.1 (suite)
Composante Compor-
Vitesse initiale
Conditions de fréquence tement
de modifi- Effet sur la
entraînant la principale de ultérieur de Comportement
Défaut cation de vitesse de réso- Répétabilité Commentaires
modification l'amplitude de la vibra- sur le vireur
l'amplitude nance
des vibrations vibration modi- tion avec le
des vibrations
fiée temps
L'inversion de la
période transitoire
n'inversera pas
immédiatement
Les tendances, le changement de
Peut augmenter
mais pas né- vibration. Corrélé
ou diminuer selon
Dans des cessairement avec les pressions
Principalement que l'élévation du
Lente, sauf si conditions les ampli- des films des paliers
Modification de Après une pé- 1x. Moins d’1x palier est vers le
le tourbillon établies, tudes, auront et les températures
l’élévation des riode transitoire peut apparaître haut ou vers le Aucun
d'huile est pré- atteint une tendance à du métal. Ce défaut
paliers opérationnelle (voir tourbillon- bas. Les rotors
dominant nouvelle se répéter est typiquement
nement d'huile) adjacents peuvent
stabilité après des limité aux turbines
subir l'effet
transitions avec deux paliers par
inverse
similaires rotor. Les turbines
avec un seul palier
par rotor ont ten-
dance à être moins
sensibles à ce défaut.
NOTES:
a) Un léger frottement a tendance à se produire entre l'arbre et les joints stationnaires, qui sont des endroits où les jeux sont réduits par conception et où des mesures sont prises
par le fabricant dans la conception des joints pour minimiser les effets du frottement, par exemple en utilisant des bagues d'étanchéité segmentées à ressort et/ou des ailettes
d'étanchéité en laiton/bronze.
b) Le frottement dur a tendance à se produire à d'autres endroits où le frottement n'est généralement pas prévu par la conception et où un contact plus important peut donc se
produire.
c) L'effet Morton désigne une condition de vibration dans laquelle un réchauffement visqueux de la surface de l'arbre se produit en raison du cisaillement de l'huile dans un film
d'huile étroit d'un palier à film fluide, ce qui entraîne une courbure thermique temporaire de l'arbre.

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ISO 13373-4:2021(F)
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Tableau A.1 (suite)
Composante Compor-
Vitesse initiale
Conditions de fréquence tement
de modifi- Effet sur la
entraînant la principale de ultérieur de Comportement
Défaut cation de vitesse de réso- Répétabilité Commentaires
modification l'amplitude de la vibra- sur le vireur
l'amplitude nance
des vibrations vibration modi- tion avec le
des vibrations
fiée temps
Diminue
Pendant ou après
avec la
une période
réduction de La rotation
transitoire, chute
la vitesse, lente augmen-
En cas de courbures
importante de
Courbure sauf si tra- Niveau de vibra- tera généra-
Rapide - sou- importantes le
température ou
permanente de 1x versée par tion significative- lement pour Oui
vent important moteur du vireur ne
modification du
l'arbre la vitesse de ment modifié atteindre un
s’enclenchera pas.
rotor dans la
résonance. nouveau niveau
carcasse
Se stabilisera plus stable
à un régime
position
stable
Bien surveil- Répétition à
Revient à la La rotation
ler les chan- chaque dé- Peut être causée par
valeur précé- Le niveau de lente reviendra
Courbure transi- Durant un gements de marrage dans l'effet bimétallique et
dente après vibration peut au niveau nor-
toire de l'arbre changement de température. 1x les mêmes l'émissivité différen-
stabilisation considérablement mal précédent
sans frottement température Dépend de la conditions de tielle des matériaux
de la tempé- changer au bout d'un
construction du fonctionne- de l'arbre.
rature certain temps
rotor. ment
NOTES:
a) Un léger frottement a tendance à se produire entre l'arbre et les joints stationnaires, qui sont des endroits où les jeux sont réduits par conception et où des mesures sont prises
par le fabricant dans la conception des joints pour minimiser les effets du frottement, par exemple en utilisant des bagues d'étanchéité segmentées à ressort et/ou des ailettes
d'étanchéité en laiton/bronze.
b) Le frottement dur a tendance à se produire à d'autres endroits où le frottement n'est généralement pas prévu par la conception et où un contact plus important peut donc se
produire.
c) L'effet Morton désigne une condition de vibration dans laquelle un réchauffement visqueux de la surface de l'arbre se produit en raison du cisaillement de l'huile dans un film
d'huile étroit d'un palier à film fluide, ce qui entraîne une courbure thermique temporaire de l'arbre.

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ISO 13373-4:2021(F)
8
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Tableau A.1 (suite)
Composante Compor-
Vitesse initiale
Conditions de fréquence tement
de modifi- Effet sur la
entraînant la principale de ultérieur de Comportement
Défaut cation de vitesse de réso- Répétabilité Commentaires
modification l'amplitude de la vibra- sur le vireur
l'amplitude nance
des vibrations vibration modi- tion avec le
des vibrations
fiée temps
1x, contact lourd, La rotation L'inversion de la
apparent sous lente peut vitesse ou le chan-
Variable. Si elle forme de points augmenter gement de charge
Changement de est rapide, il est plats sur orbites, Amplitude immédiatement Pas nécessai- rétablit assez rapide-
Courbure transi- Le niveau de
vitesse ou de très probable pourrait égale- cyclique avec après un ralen- rement répé- ment les niveaux de
toire de l’arbre - vibration peut
charge. Contact qu’une cour- ment provoquer rotation ou tissement et table à chaque vibrations anté-
avec frottement considérablement
entre pièces fixes bure perma- des réponses variation de elle diminuera période rieurs. Le vecteur
dur changer
et tournantes nente appa- aux fréquences phase
...

FINAL
INTERNATIONAL ISO/FDIS
DRAFT
STANDARD 13373-4
ISO/TC 108/SC 2
Condition monitoring and diagnostics
Secretariat: DIN
of machines — Vibration condition
Voting begins on:
2021-08-24 monitoring —
Voting terminates on:
Part 4:
2021-10-19
Diagnostic techniques for gas and
steam turbines with fluid-film
bearings
Surveillance et diagnostic d'état des machines — Surveillance des
vibrations —
Partie 4: Techniques de diagnostic pour turbines à gaz et turbines à
vapeur à paliers à film fluide
RECIPIENTS OF THIS DRAFT ARE INVITED TO
SUBMIT, WITH THEIR COMMENTS, NOTIFICATION
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ISO/FDIS 13373-4:2021(E)
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NATIONAL REGULATIONS. ISO 2021

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ISO/FDIS 13373-4:2021(E)

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© ISO 2021
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ii © ISO 2021 – All rights reserved

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ISO/FDIS 13373-4:2021(E)

Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Measurements . 2
4.1 Vibration measurements . 2
4.2 Machine operational parameter measurement . 2
5 Initial analysis . 2
6 Specific analysis of gas and steam turbines with fluid-film bearings .3
7 Considerations when recommending actions . 3
Annex A (normative) Systematic approach for vibration analysis of gas and steam turbines
with fluid-film bearings . 4
Annex B (informative) Methodology for diagnosing vibration problems of gas and steam
turbines with fluid-film bearings .12
Annex C (informative) Examples of vibration problems in steam turbines with fluid-film
bearings .17
Bibliography .21
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ISO/FDIS 13373-4:2021(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 108, Mechanical vibration, shock and
condition monitoring, Subcommittee SC 2, Measurement and evaluation of mechanical vibration and shock
as applied to machines, vehicles and structures.
A list of all parts in the ISO 13373 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.
iv © ISO 2021 – All rights reserved

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ISO/FDIS 13373-4:2021(E)

Introduction
This document provides guidelines for the procedures to be considered when carrying out vibration
diagnostics of gas turbines and steam turbines on fluid-film bearings. It is intended to be used by
vibration practitioners, engineers and technicians and it provides them with useful diagnostic tools.
These tools include the use of diagnostic flowcharts, process tables, fault tables and symptom tables.
The material contained in this document presents the most basic, logical, and intelligent steps that
should be taken when diagnosing problems associated with these particular types of machines.
The ISO 20816 series of standards contains acceptable vibration magnitudes and zones for various
types and sizes of machines, ranging from new and well-running machines to machines that are in
danger of failing.
ISO 13373-1 presents the basic procedures for vibration narrow-band signal analysis. It includes: the
types of transducers used, their ranges and their recommended locations on various types of machines;
on-line and periodic vibration monitoring systems; and potential machinery problems.
ISO 13373-2 includes descriptions of the signal conditioning equipment that is required; time and
frequency domain techniques; and the waveforms and signatures that represent the most common
machinery operating phenomena or machinery faults that are encountered when performing vibration
signature analysis.
ISO 13373-3 provides some procedures to determine the causes of vibration problems common to all
types of rotating machines. It includes: systematic approaches to characterize vibration effects; the
diagnostic tools available; which tools are needed for particular applications; and recommendations
on how the tools are to be applied to different machine types and components. However, this does not
preclude the use of other diagnostic techniques.
It should be noted that ISO 17359 indicates that diagnostics can be
— started as a succeeding activity after detection of an anomaly during monitoring, or
— executed synchronous with monitoring from the beginning.
This document considers only the former in which diagnostics is performed after an anomaly has been
detected. Moreover, this document focusses mainly on the use of flowcharts and process tables as
diagnostic tools, as well as fault tables and symptom tables, since it is felt that these are the tools that
are most appropriate for use by practitioners, engineers and technicians in the field.
The flowchart and diagnostic process table methodology presents a structured procedure for a person
in the field to diagnose a fault and find its cause. This step-by-step procedure should be able to guide
the practitioner in the vibration diagnostics of the machine anomaly, in order to reach the probable root
cause of this anomaly.
The fault tables present a list of the most common faults in machinery, as well as their manifestations in
the machine and vibration data. The symptom tables contain the main distinguishing vibration features
of the main faults. When used with the flowcharts, the tables assist with the identification of machinery
faults.
When approaching a machinery problem that manifests itself as a high or erratic vibration signal, the
diagnosis of the problem should be done in a well thought out, systematic manner. This document and
ISO 13373-3 achieve that purpose by providing to the analyst guidance on the selection of the proper
measuring tools, the analysis tools and their use, and the step-by-step recommended procedures for the
diagnosis of problems associated with various types of gas and steam turbines with fluid-film bearings.
VDI 3839-4 provides typical vibration patterns in steam and gas turbines, and can be a useful reference.
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FINAL DRAFT INTERNATIONAL STANDARD ISO/FDIS 13373-4:2021(E)
Condition monitoring and diagnostics of machines —
Vibration condition monitoring —
Part 4:
Diagnostic techniques for gas and steam turbines with
fluid-film bearings
1 Scope
This document sets out guidelines for the specific procedures to be considered when carrying out
vibration diagnostics of various types of gas and steam turbines with fluid-film bearings.
This document is intended to be used by condition monitoring practitioners, engineers and technicians
and provides a practical step-by-step vibration-based approach to fault diagnosis. In addition, it gives
examples for a range of machine and component types and their associated fault symptoms.
The approach given in this document is based on established good practice, put together by
experienced users, although it is acknowledged that other approaches can exist. Recommended actions
for a particular diagnosis depend on individual circumstances, the degree of confidence in the fault
diagnosis (e.g. has the same diagnosis been made correctly before for this machine), the experience of
the practitioner, the fault type and severity as well as on safety and commercial considerations. It is
neither possible nor the aim of this document to recommend actions for all circumstances.
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.
ISO 2041, Mechanical vibration, shock and condition monitoring — Vocabulary
ISO 13372, Condition monitoring and diagnostics of machines — Vocabulary
ISO 13373-1, Condition monitoring and diagnostics of machines — Vibration condition monitoring —
Part 1: General procedures
ISO 13373-2, Condition monitoring and diagnostics of machines — Vibration condition monitoring —
Part 2: Processing, analysis and presentation of vibration data
ISO 13373-3:2015, Condition monitoring and diagnostics of machines — Vibration condition monitoring —
Part 3: Guidelines for vibration diagnosis
ISO 21940-2, Mechanical vibration — Rotor balancing — Part 2: Vocabulary
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 2041, ISO 13372 and
ISO 21940-2 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
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ISO/FDIS 13373-4:2021(E)

— IEC Electropedia: available at https:// www .electropedia .org/
4 Measurements
4.1 Vibration measurements
Vibration measurements may be obtained using two main categories of transducers:
a) non-contacting, e.g. inductive, capacitive and eddy current probes used on rotating shafts;
b) seismic transducers, e.g. accelerometers or velocity transducers used on non-rotating parts, such
as bearing housings.
International Standards have been written to help in assessing the vibration severity for both of these
types of measurements, for instance the ISO 7919 series, the ISO 10816 series and the ISO 20816 series.
Guidance for the selection of the appropriate International Standard is given in ISO/TR 19201.
It is important to recognize that the appropriate transducer, signal conditioning, measurement and
analysis system should be used for the diagnosis of faults considering specific situations in gas and
steam turbines with fluid-film bearings. Before any measurements are taken, it is good practice to
consider whether the grounding and electrical fields of the machine will have any effect on them.
Descriptions of transducers, measurement systems and analysis techniques are given in ISO 13373-1
and ISO 13373-2, which shall be considered for appropriate selection.
4.2 Machine operational parameter measurement
Operational parameters (e.g. rotational speed, load, mounting configuration (rigid or flexible support
arrangement) and temperature), that can have an influence on machine vibration characteristics are
important in order to arrive at an appropriate fault diagnosis. For a given machine, these parameters
can be associated with a range of steady-state and transient operating conditions.
5 Initial analysis
An initial fault analysis shall be performed using the guidelines given in ISO 13373-3:2015, Annex A and
shall identify any safety concerns such as the
a) presence and severity of any high vibration,
b) past history of the machine,
c) effects of the machine operating parameters,
d) consequence of not taking any necessary corrective action to reduce machine vibration, and
e) need for shutting the turbine down to prevent damage.
In addition, other factors such as the
f) measurement transducer mounting configuration,
g) the effect of any nearby rotating machines, and
h) the effect of the building and the machine foundation [e.g. platform foundation (onshore and
offshore) environment].
on the machine under consideration should be taken into account during the initial analysis of machine
performance. Also see ISO 13373-3:2015, Annexes B to D for a description of some common machine
faults (e.g. installation and bearing defects).
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ISO/FDIS 13373-4:2021(E)

6 Specific analysis of gas and steam turbines with fluid-film bearings
The systematic procedure used in the ISO 13373 series includes usage of fault tables, symptom tables
and a step-by-step methodology of vibration diagnosis of faults. For this document, the fault table
for the diagnosis of gas and steam turbines with fluid-film bearings to be used is given by Table A.1,
the symptom table is given in Table A.2, while the methodology of vibration diagnosis is presented
in Annex B. Examples of the use of the fault table, symptom table and methodology of vibration
diagnosis of gas and steam turbines with fluid-film bearings are given in Annex C. Note that these
annexes do not cover turbine vibration from hydrodynamic bearing problems which are addressed in
ISO 13373-3:2015, Annex C.
This approach is considered to be good practice put together by experienced users, although it is
acknowledged that other approaches can exist.
It should be noted that in some cases the vibration diagnosis can point to several root causes and it is
recommended that an expert is consulted in order to establish the most probable fault.
7 Considerations when recommending actions
A number of factors influence any remedial or corrective actions to be taken, such as
a) their safety,
b) commercial considerations,
c) incorrect machine design, and
d) machine assembly issues.
Clearly, the appropriate action(s) for a particular diagnosis depend(s) on individual circumstances and
it is beyond the scope of this document to make specific recommendations. Nevertheless, it is important
to consider possible actions resulting from the diagnosis and the implications of those actions.
Recommended actions depend on the degree of confidence in the fault diagnosis (e.g. has the same
diagnosis been made correctly before for this machine?), the fault type and severity as well as on safety
and commercial considerations. It is neither possible nor the aim of this document to recommend
actions for all circumstances.
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ISO/FDIS 13373-4:2021(E)

Annex A
(normative)

Systematic approach for vibration analysis of gas and steam
turbines with fluid-film bearings
A systematic approach to vibration analysis of gas and steam turbines with fluid-film bearings is given
by the fault table in Table A.1, and the symptom table given in Table A.2. The information included in
Table A.1 is not intended to be exhaustive, but includes the most prevalent faults associated with steam
and gas turbines with fluid film bearings.
4 © ISO 2021 – All rights reserved

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ISO/FDIS 13373-4:2021(E)

© ISO 2021 – All rights reserved 5
Table A.1 — Fault table for vibration analysis of gas and steam turbines with fluid-film bearings
Conditions Initial rate Major frequency Subsequent
under which the of change of component of behaviour Effect on reso- Behaviour on
Fault Repeatability Comments
vibration change vibration am- changed vibra- of vibration nance speed barring
occurs plitude tion amplitude with time
Immediately
Shaft unbalance Steady state 1x Steady None Not affected Repeatable None
evident
For turbines consist-
ing of multiple rotors
Shaft unbalance in tandem, the larg-
resulting from Usually steady Step change Steady fol- Vibration level Rubbing can est changes usually
rotating com- state but can be or series of 1x lowing step significantly be heard in None occur at the bearings
ponent material transient changes change changed extreme cases of the affected rotor.
loss Rotor unbalance
may be due to blade
erosion.
Reversal of transient
will not immediately
May increase reverse the vibration
or decrease change. Correlate
depending on Trends, but with bearing wedge
Under steady whether the not necessari- pressures and metal
Predominantly
Slow, unless oil conditions a bearing eleva- ly amplitudes temperatures. This
Bearing eleva- Following opera- 1x. Less than 1x
whirl is pre- new steady tion is raised None will tend to fault is typically
tion change tional transient can be exhibited
dominant level will be or lowered. repeat follow- limited to turbines
(see oil whirl).
reached Adjacent rotors ing similar with two bearings
may experience transients per rotor. Turbines
the opposite with a single bearing
effect per rotor tend to be
less susceptible to
this fault.
NOTES:
— Light rubbing tends to occur between the shaft and the stationary seals, which are locations where the clearances are small by design and steps are taken by the manufacturer
in the design of the seals to minimise the effects of rubbing, e.g. through the use of spring-backed segmented seal rings and/or brass/bronze seal fins.
— Hard rubbing tends to occur at other locations where rubbing is not generally intended to occur by design and therefore more substantial contact can occur.
— The Morton effect refers to a vibration condition where viscous heating of the shaft surface occurs due to shearing of the oil in a narrow oil film of a fluid-film bearing, leading
to a temporary thermal bend of the shaft.

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ISO/FDIS 13373-4:2021(E)

6 © ISO 2021 – All rights reserved
Table A.1 (continued)
Conditions Initial rate Major frequency Subsequent
under which the of change of component of behaviour Effect on reso- Behaviour on
Fault Repeatability Comments
vibration change vibration am- changed vibra- of vibration nance speed barring
occurs plitude tion amplitude with time
Reduces with
speed reduc-
During or follow-
tion, except
ing a transient,
Slow roll run-
when pass-
large temper-
Vibration level out will gener- With severe bends
Permanent bend Rapid – often ing through
ature drop or
1x significantly ally increase to Yes barring motor will
in the shaft large resonance
change in rotor to
changed a new, higher not engage.
speed. Will
casing
steady level
stabilize at
position
new steady
level
Will revert
Closely follows to previ- Slow roll run- Repeats at Can be caused by the
Transient bend temperature ous value Vibration level out will decay each start bi-metal effect and
During tempera-
in the shaft with change. De- 1x following can be signifi- to previous nor- for the same differential emis-
ture change
no rubbing pends on rotor stabilization cantly changed mal level over a operating sivity of the shaft
construction. of tempera- period of time conditions materials.
ture.
Reversal of speed
1x, heavy contact, Slow roll can be
or load change will
apparent as flat higher imme-
Variable. If Cyclic Not necessar- restore previous
Speed or load spots on orbits, diately after
Transient bend rapid a perma- amplitude Vibration level ily repeatable vibration levels fairly
change. Station- might also cause rundown and
in the shaft with nent bend will with phase can be signifi- each time the quickly. Vector will
ary and rotating responses at will decay to
hard rubbing almost certainly rotation or cantly changed transient is rotate with a period
parts contact natural frequen- previous level
develop variation undergone of typically 1/2 h
cies and higher over a period of
to 3 h. Depends on
harmonics. time
construction.
NOTES:
— Light rubbing tends to occur between the shaft and the stationary seals, which are locations where the clearances are small by design and steps are taken by the manufacturer
in the design of the seals to minimise the effects of rubbing, e.g. through the use of spring-backed segmented seal rings and/or brass/bronze seal fins.
— Hard rubbing tends to occur at other locations where rubbing is not generally intended to occur by design and therefore more substantial contact can occur.
— The Morton effect refers to a vibration condition where viscous heating of the shaft surface occurs due to shearing of the oil in a narrow oil film of a fluid-film bearing, leading
to a temporary thermal bend of the shaft.

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ISO/FDIS 13373-4:2021(E)

© ISO 2021 – All rights reserved 7
Table A.1 (continued)
Conditions Initial rate Major frequency Subsequent
under which the of change of component of behaviour Effect on reso- Behaviour on
Fault Repeatability Comments
vibration change vibration am- changed vibra- of vibration nance speed barring
occurs plitude tion amplitude with time
Increase clear-
1x periodic am-
ance (e.g. by rotor
Typically
plitude and phase
Slow roll run- alignment change)
goes into a
change.
out can be high- to eliminate rubbing.
limit cycle.
er immediately Alternatively, reduce
Periodicity is
Morton effect/ Howev- Vibration level
Steady speed after run-down Usually re- vibration to reduce
dependent on the
Newkirk effect Slowly develops er, it can can be signifi-
conditions and will decay peatable effect. Can require
severity of the
(light rubbing) disappear cantly changed.
to previous level balancing. Reduce
rub and can vary
temporarily
over a period of overhanging mass
between minutes
and then
time if present. Solution
and several
reappear
can involve bearing
hours.
modification.
Predominantly
just less than Significant speed
Erratic
0,5x, for whip reduction required
at higher
Speed change or it locks at rotor to eliminate the
Oil whirl (or level than
during bearing Very rapid first resonance None Not present Will repeat increased vibration.
whip) normal and
unloading frequency de- Will repeat under
frequently
pending on rotor identical operating
unstable
design (rigid or conditions.
flexible).
Increase in steam
flow on load. Can Load dependent.
also occur with Modify admission
1x load depend- Will repeat
Steam-induced bearing height sequence; repair
Often very rapid ent for concen- None None None until source is
vibration change. Occurs diaphragms; install
tricity problems corrected
in HP or HP-IP nozzle blocks prop-
steam turbine erly.
cylinders
NOTES:
— Light rubbing tends to occur between the shaft and the stationary seals, which are locations where the clearances are small by design and steps are taken by the manufacturer
in the design of the seals to minimise the effects of rubbing, e.g. through the use of spring-backed segmented seal rings and/or brass/bronze seal fins.
— Hard rubbing tends to occur at other locations where rubbing is not generally intended to occur by design and therefore more substantial contact can occur.
— The Morton effect refers to a vibration condition where viscous heating of the shaft surface occurs due to shearing of the oil in a narrow oil film of a fluid-film bearing, leading
to a temporary thermal bend of the shaft.

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ISO/FDIS 13373-4:2021(E)

8 © ISO 2021 – All rights reserved
Table A.1 (continued)
Conditions Initial rate Major frequency Subsequent
under which the of change of component of behaviour Effect on reso- Behaviour on
Fault Repeatability Comments
vibration change vibration am- changed vibra- of vibration nance speed barring
occurs plitude tion amplitude with time
Return to steam flow
below original will
Increase in steam
immediately reverse
flow on load. Can Subsynchro-
the vibration change.
also occur with nous – normally Will repeat
However, it should
bearing height at frequency of during similar
Steam whirl Often very rapid None None None be noted that there
change. Occurs resonance speed steam flow
is often a hyster-
in HP or HP-IP of the rotor in increases
esis effect which
steam turbine question.
requires the steam
cylinders
flow reduction to be
significant.
Vibration
will remain
Flow – Pressure
high unless Will repeat Return to appropri-
Rotating stall
conditions.
Violent and very there is a during similar ate flow will imme-
in gas turbine Subsynchronous None None
rapid change in flow condi- diately reverse the
Stall is separation
compressors
speed or tions vibration change.
of flow on airfoil,
inlet guide
vane position
Vibration
will remain
Flow – Pressure
Compressor high unless Will repeat Return to appropri-
conditions.
Subsynchronous
surge in gas tur- Violent and very there is a during similar ate flow will imme-
– not a discrete None None
surge is whole
bine compres- rapid change in flow condi- diately reverse the
frequency
compressor
sors speed or tions vibration change.
choking
inlet guide
vane position
NOTES:
— Light rubbing tends to occur between the shaft and the stationary seals, which are locations where the clearances are small by design and steps are taken by the manufacturer
in the design of the seals to minimise the effects of rubbing, e.g. throu
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