TC 4 - Hydraulic turbines

IEC 63132-5:2023 to establish, in a general way, suitable procedures and tolerances for the installation of hydroelectric turbines and generators. This guide presents a typical assembly. It should be recognized that there are many possible ways to assemble a unit. The size of the machines, design of the machines, layout of the powerhouse and delivery schedule of the components are some of the elements that could result in additional steps, the elimination of some steps and/or assembly sequences.

IEC 63132-6:2023 is to establish, in a general way, suitable procedures and tolerances for the installation of Pelton vertical turbines. This document presents a typical assembly and whenever the word "turbine" is used in this document, it refers to a vertical Pelton turbine. There are many possible ways to assemble a unit. The size of the machine, the design of the machine, the layout of the powerhouse or the delivery schedule of the components are some of the elements that could result in additional steps, or the elimination of some steps and/or assembly sequences.

IEC/IEEE 63198-2775:2023 describes the integrated control and management of smart hydroelectric power plants and groups of plants using the latest proven and widely accepted digital equipment. The descriptions are applicable to all types of hydroelectric power plants except tidal and ocean power plants.
Based on internationally standardized communication models, this document incorporates guidelines for communication networks, sensors, local monitoring and control equipment, Integrated Control and Management Platform (ICAMP) as well as intelligent applications. In addition, special attention is also given to cyber security.
This document considers the future structure of completely digitalized power plants equipped with digitalized sensors and actuators as well as the intelligent control and management of power plants with existing instrumentation.

The purpose of IEC 60545:2021 is to establish, in a general way, suitable procedures for commissioning and operation of hydraulic machines and associated equipment, and to indicate how such machines and equipment should be commissioned and operated. Commissioning and operation of the associated equipment are not described in detail in this document but is considered in the commissioning and operation procedure as a separate step. Machines of up to about 15 MW and reference diameters of about 3 m are generally covered by IEC 62006. It is understood that a guideline of this type will be binding only if the contracting parties have agreed upon it. The guidelines exclude matters of purely commercial interest, except those inextricably connected with the conduct of commissioning and operation. The guidelines are not concerned with waterways, gates, drainage pumps, cooling-water equipment, generators, motor-generators, electrical equipment (e.g. circuit breakers, transformers) etc., except where they cannot be separated from the hydraulic machinery and its equipment. Wherever the guidelines specify that documents, drawings or information are supplied by a supplier (or by suppliers), each individual supplier should furnish the appropriate information for its own supply only. This second edition cancels and replaces the first edition published in 1976 and the first edition of IEC 60805 published in 1985. This edition constitutes a technical revision. This edition includes the following significant technical changes with respect to the previous edition:
a) the focus is on the commissioning and operation of the hydraulic machine. Interfaces to the electric machine are mentioned only for a better understanding of the context;
b) the definitions of tests for commissioning and adjustable speed are updated to state of the art;
c) the record sheets ‘measurements during erection’ are excluded (see IEC 63132 (all parts));
d) the maintenance is excluded (see IEC 62256).

IEC/TS 62882:2020(E) which is a Technical Specification, provides pressure fluctuation transposition methods for Francis turbines and pump-turbines operating as turbines, including:
- description of pressure fluctuations, the phenomena causing them and the related problems;
- characterization of the phenomena covered by this document, including but not limited to inter-blade vortices, draft tube vortices rope and rotor-stator interaction;
- demonstration that both operating conditions and Thoma numbers (cavitation conditions) are primary parameters influencing pressure fluctuations;
- recommendation of ways to measure and analyse pressure fluctuations;
- identification of potential resonances in test rigs and prototypes;
- identification of methods, to transpose the measurement results from model to prototype or provide ways to predict pressure fluctuations in prototypes based on statistics or experience;
- recommendation of a data acquisition system, including the type and mounting position of model and prototype transducers and to define the similitude condition between model and prototype;
- presentation of pressure fluctuation measurements comparing the model turbine and the corresponding prototype;
- discussion of parameters used for the transposition from model to prototype, for example, the peak to peak value at 97 % confidence interval, the RMS value or the standard deviation in the time domain and the relation of main frequency and the rotational frequency in the frequency domain obtained by FFT;
- discussion of the uncertainty of the pressure fluctuation transposition from model to prototype;
- discussion of factors which influence the transposition, including those which cannot be simulated on the model test rig such as waterway system and mechanical system;
- establishment of the transposition methods for different types of pressure fluctuations;
- suggestion of possible methods for mitigating pressure fluctuation;
- definition of the limitations of the specification.
This document is limited to normal operation conditions. Hydraulic stability phenomena related to von Karman vortices, transients, runaway speed and speed no load are excluded from this document.
This document provides means to identify potential resonances in model test rigs and prototype turbines. Scaling-up resonance conditions are not treated in this document. When resonance exists, the transposition methods identified in this document do not apply. Under these conditions, the relationship between model and prototype pressure fluctuations cannot be determined.
This document is concerned neither with the structural details of the machines nor the mechanical properties of their components, so long as these characteristics do not affect model pressure fluctuations or the relationship between model and prototype pressure fluctuations.

The purpose of IEC 63132-3:2020 is to establish, in a general way, suitable procedures and tolerances for the installation of a vertical Francis turbine or pump-turbine. This document presents a typical assembly and whenever the word “turbine” is used in this document, it refers to a vertical Francis turbine or a pump-turbine. There are many possible ways to assemble a unit. The size of the machine, design of the machine, layout of the powerhouse or delivery schedule of the components are some of the elements that could result in additional steps, the elimination of some steps and/or assembly sequences. It is understood that a publication of this type will be binding only if, and to the extent that, both contracting parties have agreed upon it. This document excludes matters of purely commercial interest, except those inextricably bound up with the conduct of installation. The tolerances in this document have been established upon best practices and experience, although it is recognized that other standards specify different tolerances. Wherever this document specifies that documents, drawings or information is supplied by a manufacturer (or by manufacturers), each individual manufacturer will furnish the appropriate information for their own supply only.

The purpose of IEC 63132-4:2020 is to establish, in a general way, suitable procedures and tolerances for the installation of a vertical Kaplan or propeller turbine. This document presents a typical assembly and whenever the word “turbine” is used in this document, it refers to a vertical Kaplan or propeller turbine. There are many possible ways to assemble a unit. The size of the machine, design of the machine, layout of the powerhouse or delivery schedule of the components are some of the elements that could result in additional steps, the elimination of some steps and/or assembly sequences. It is understood that a publication of this type will be binding only if, and to the extent that, both contracting parties have agreed upon it. This document excludes matters of purely commercial interest, except those inextricably bound up with the conduct of installation. The tolerances in this document have been established upon best practices and experience, although it is recognized that other standards specify different tolerances. Wherever this document specifies that documents, drawings or information is supplied by a manufacturer (or by manufacturers), each individual manufacturer will furnish the appropriate information for their own supply only.

The purpose of IEC 63132-2:2020 is to establish, in a general way, suitable procedures and tolerances for installation of generator. This document presents a typical assembly. There are many possible ways to assemble a unit. The size of the machines, design of the machines, layout of the powerhouse or delivery schedule of the components are some of the elements that could result in additional steps, the elimination of some steps and/or assembly sequences. It is understood that a publication of this type will be binding only if, and to the extent that, both contracting parties have agreed upon it. This document excludes matters of purely commercial interest, except those inextricably bound up with the conduct of installation. This document applies to vertical generators according to IEC 60034-7. The tolerances in this document have been established upon best practices and experience, although it is recognized that other standards specify different tolerances. Brushless excitation system is not included in this document. Wherever this document specifies that documents, drawings or information is supplied by a manufacturer (or by manufacturers), each individual manufacturer will furnish the appropriate information for their own supply only.

The purpose of IEC 63132-1:2020 is to establish, in a general way, suitable procedures and tolerances for the installation of hydroelectric turbines and generators. This document presents a typical assembly. There are many possible ways to assemble a unit. The size of the machines, design of the machines, layout of the powerhouse and delivery schedule of the components are some of the elements that could result in additional steps, the elimination of some steps and/or assembly sequences. It is understood that a publication of this type will be binding only if, and to the extent that, both contracting parties have agreed upon it. Installations for refurbishment projects or for small hydro projects are not in the scope of this document. An agreement between all parties is necessary. This document excludes matters of purely commercial interest, except those inextricably bound up with the conduct of installation. The tolerances in this document have been established upon best practices and experience, although it is recognized that other standards specify different tolerances. Wherever this document specifies that documents, drawings or information is supplied by a manufacturer (or manufacturers), each individual manufacturer will furnish the appropriate information for their own supply only.

IEC 60193:2019 applies to laboratory models of any type of impulse or reaction hydraulic turbine, storage pump or pump-turbine.
This document applies to models of prototype machines either with unit power greater than 5 MW or with reference diameter greater than 3 m. Full application of the procedures herein prescribed is not generally justified for machines with smaller power and size. Nevertheless, this document may be used for such machines by agreement between the purchaser and the supplier.
This document excludes all matters of purely commercial interest, except those inextricably bound up with the conduct of the tests.
This document is concerned with neither the structural details of the machines nor the mechanical properties of their components, so long as these do not affect model performance or the relationship between model and prototype performances.
This document covers the arrangements for model acceptance tests to be performed on hydraulic turbines, storage pumps and pump-turbines to determine if the main hydraulic performance contract guarantees (see 4.2) have been satisfied.
It contains the rules governing test conduct and prescribes measures to be taken if any phase of the tests is disputed.
The main objectives of this document are:
– to define the terms and quantities used;
– to specify methods of testing and of measuring the quantities involved, in order to ascertain the hydraulic performance of the model;
– to specify the methods of computation of results and of comparison with guarantees;
– to determine if the contract guarantees that fall within the scope of this document have been fulfilled;
– to define the extent, content and structure of the final report.
The guarantees can be given in one of the following ways:
– guarantees for prototype hydraulic performance, computed from model test results considering scale effects;
– guarantees for model hydraulic performance.
This third edition cancels and replaces the second edition published in 1999. This edition constitutes a technical revision.
This edition includes the following significant technical changes with respect to the previous edition:
a) update to methods/measuring tools currently used for checking dimensions on both model and prototype;
b) update to requirements of accuracy in the dimensional check procedure as a result of new technology;
c) merging of tables/sections with redundant information in dimension check in 5.2;
d) update to methods of measuring discharge;
e) update to pressure fluctuation methods and terminology;
f) specification of measuring times for accurate pressure fluctuation analyses in the model;
g) redefine definition for the transposition of pressure fluctuations to prototype;
h) update to surface waviness requirements in prototype;
i) redefining methods/references in clause on cavitation nuclei content (5.7.3.2.2);
j) update to 7.3 and review of methods on radial thrust measurements;
k) update to 7.4 (Hydraulic loads on control components);
l) update and develop methodology in 7.5 for testing in the extended operating range;
m) update to 7.6 concerning index testing;
n) update to methods for measuring roughness;
o) updates to references;
p) updates to figures;
q) revision of sigma definition;
r) reference to new method of transposition in accordance with IEC 62097.
Key Words: Hydraulic Turbines, Storage Pumps, Pump Turbines

IEC 62364:2019 is available as IEC 62364:2019 RLV which contains the International Standard and its Redline version, showing all changes of the technical content compared to the previous edition.
IEC 62364:2019 gives guidelines for:
a) presenting data on hydro-abrasive erosion rates on several combinations of water quality, operating conditions, component materials, and component properties collected from a variety of hydro sites;
b) developing guidelines for the methods of minimizing hydro-abrasive erosion by modifications to hydraulic design for clean water. These guidelines do not include details such as hydraulic profile shapes which are determined by the hydraulic design experts for a given site;
c) developing guidelines based on “experience data” concerning the relative resistance of materials faced with hydro-abrasive erosion problems;
d) developing guidelines concerning the maintainability of materials with high resistance to hydro-abrasive erosion and hardcoatings;
e) developing guidelines on a recommended approach, which owners could and should take to ensure that specifications communicate the need for particular attention to this aspect of hydraulic design at their sites without establishing criteria which cannot be satisfied because the means are beyond the control of the manufacturers;
f) developing guidelines concerning operation mode of the hydro turbines in water with particle materials to increase the operation life.
It is assumed in this document that the water is not chemically aggressive. Since chemical aggressiveness is dependent upon so many possible chemical compositions, and the materials of the machine, it is beyond the scope of this document to address these issues. It is assumed in this document that cavitation is not present in the turbine. Cavitation and hydro-abrasive erosion can reinforce each other so that the resulting erosion is larger than the sum of cavitation erosion plus hydro-abrasive erosion. The quantitative relationship of the resulting hydro-abrasive erosion is not known and it is beyond the scope of this document to assess it, except to suggest that special efforts be made in the turbine design phase to minimize cavitation. Large solids (e.g. stones, wood, ice, metal objects, etc.) traveling with the water can impact turbine components and produce damage. This damage can in turn increase the flow turbulence thereby accelerating wear by both cavitation and hydro-abrasive erosion. Hydro-abrasive erosion resistant coatings can also be damaged locally by impact of large solids. It is beyond the scope of this document to address these issues. This document focuses mainly on hydroelectric powerplant equipment. Certain portions can also be applicable to other hydraulic machines. This second edition cancels and replaces the first edition published in 2013. This edition constitutes a technical revision. This edition includes the following significant technical changes with respect to the previous edition:
a) the formula for TBO in Pelton reference model has been modified;
b) the formula for calculating sampling interval has been modified;
c) the chapter in hydro-abrasive erosion resistant coatings has been substantially modified;
d) the annex with test data for hydro-abrasive erosion resistant materials has been removed;
e) a simplified hydro-abrasive erosion evaluation has been added.
Key words: Hydraulic Machines, Hydro-Abrasive Erosion, Kaplan, Francis, Pelton Turbines.

ISO 20816-5:2018 This document provides guidelines for evaluating the vibration measurements made at the bearings, bearing pedestals or bearing housings and also for evaluating relative shaft vibration measurements made on machine sets in hydraulic power generating and pump-storage plants when the machine is operating within its normal operating range. The normal operating ranges for each type of turbine covered by this document are defined in Annex A.
This document is applicable to machine sets in hydraulic power generating plants and in pump-storage plants with typical rotational speeds of 60 r/min to 1 000 r/min fitted with shell or pad (shoe) type oil-lubricated bearings.
NOTE The current database includes machine speeds ranging from 60 r/min to 750 r/min (with a very small sample of 1 000 r/min machines).
This document defines different limit values of bearing housing and shaft vibration depending on the type of turbine, the orientation of the shaft (i.e. horizontal or vertical) and for each of the bearing locations.
This document is based on statistical analysis and provides criteria for the most common types of turbines, pump-turbines and pumps. For specific information on which types of units are covered in this document, see Annex A.
Machine sets covered by this document can have the following configurations:
a) generators driven by hydraulic turbines;
b) motor-generators driven by pump-turbines;
c) motor-generators driven by hydraulic turbines and separate pumps;
d) pumps driven by electric motors.
This document is not applicable to the following unit configurations, parameters and operating conditions:
— hydraulic machines with water-lubricated bearings;
— hydraulic machines or machine sets having rolling element bearings (for these machines, see IEC 62006 and/or ISO 10816‑3);
— pumps in thermal power plants or industrial installations (for these machines, see ISO 10816‑7);
— electrical machines operating as motors except for the use of these machines in pump-storage applications;
— hydro generators operating as synchronous condensers (with the water in the turbine depressed by compressed air);
— assessment of absolute bearing housing vibration displacement;
— assessment of axial vibration;
— assessment of transient conditions;
— non-synchronous operation;
— assessment of vibration of the generator stator core or the stator frame level.
Measurements made of the bearing housing vibration and shaft vibration occurring in machine sets in hydraulic power generating and pump-storage plants can be used for the following purposes:
1) Purpose A: to prevent damage arising from excessive vibration magnitudes;
2) Purpose B: to monitor changes in vibrational behaviour in order to allow diagnosis and/or prognosis.
The criteria are applicable for the vibration produced by the machine set itself. Special investigation is needed for vibration transmitted to the machine set from external sources, e.g. transmitted to the machine via the station foundations.

IEC 62256:2017 is also available as IEC 62256:2017 RLV which contains the International Standard and its Redline version, showing all changes of the technical content compared to the previous edition.
IEC 62256:2017 covers turbines, storage pumps and pump-turbines of all sizes and of the following types: Francis; Kaplan; propeller; Pelton (turbines only) and bulb turbines.
This document also identifies without detailed discussion, other powerhouse equipment that could affect or be affected by a turbine, storage pump, or pump-turbine rehabilitation. The object of this document is to assist in identifying, evaluating and executing rehabilitation and performance improvement projects for hydraulic turbines, storage pumps and pump-turbines. This document can be used by owners, consultants, and suppliers to define: needs and economics for rehabilitation and performance improvement; scope of work; specifications and evaluation of results. This document is intended to be: an aid in the decision process; an extensive source of information on rehabilitation; an identification of the key milestones in the rehabilitation process; and identification of the points to be addressed in the decision processes. This document is not intended to be a detailed engineering manual nor a maintenance document. This second edition cancels and replaces the first edition published in 2008. This edition constitutes a technical revision. This edition includes the following significant technical changes with respect to the previous edition: Tables 2 to 23 modified, completed and moved to Annex A; 7.3.2: subclauses moved with text changes; new subclauses on temperature, noise, galvanic corrosion, galling and replacement of components without assessment; 7.3.3: complete new subclause on residual life; Tables 29 to 32 moved to Annex C; New Annex B with assessment examples.
Key words: Turbines, Storage pump, Pump turbines, Rehabilitation, Performance.

IEC 62270:2013 addresses the application, design concepts, and implementation of computer-based control systems for hydroelectric plant automation. It addresses functional capabilities, performance requirements, interface requirements, hardware considerations, and operator training. It includes recommendations for system testing and acceptance. The electrical protective system (generator and step-up transformer) is beyond the scope of this guide. This second edition cancels and replaces the first edition published in 2004. This edition constitutes a technical revision. This edition includes the following significant technical changes with respect to the previous edition:
- update of system architecture aspects, with different process control system configurations;
- update of communications, user and plant interfaces aspects;
- suppression of case studies, because of the quickness of evolution of the technology;
- complete review of the bibliography, making mention of many IEC and IEEE standards as new references and addition of a new informative Annex B on legacy control systems. This publication is published as an IEC/IEEE Dual Logo standard. Key words: Hydroelectric, Automation, Computer-Based Control

IEC 62364:2013 serves to present data on particle abrasion rates on several combinations of water quality, operating conditions, component materials, and component properties collected from a variety of hydro sites; develop guidelines for the methods of minimizing particle abrasion by modifications to hydraulic design for clean water. These guidelines do not include:
- details such as hydraulic profile shapes which should be determined by the hydraulic design experts for a given site;
- develop guidelines based on "experience data" concerning the relative resistance of materials faced with particle abrasion problems;
- develop guidelines concerning the maintainability of abrasion resistant materials and hard facing coatings;
- develop guidelines on a recommended approach, which owners could and should take to ensure that specifications communicate the need for particular attention to this aspect of hydraulic design at their sites without establishing criteria which cannot be satisfied because the means are beyond the control of the manufacturers
- and develop guidelines concerning operation mode of the hydro turbines in water with particle materials to increase the operation life. It is assumed that the water is not chemically aggressive. Since chemical aggressiveness is dependent upon so many possible chemical compositions, and the materials of the machine, it is beyond the scope of this Guide to address these issues. It is assumed that cavitation is not present in the turbine. Cavitation and abrasion may reinforce each other so that the resulting erosion is larger than the sum of cavitation erosion plus abrasion erosion. The quantitative relationship of the resulting abrasion is not known and it is beyond the scope of this guide to assess it, except to recommend that special efforts be made in the turbine design phase to minimize cavitation. Large solids (e.g. stones, wood, ice, metal objects, etc.) traveling with the water may impact turbine components and produce damage. This damage may in turn increase the flow turbulence thereby accelerating wear by both cavitation and abrasion. Abrasion resistant coatings can also be damaged locally by impact of large solids. It is beyond the scope of this Guide to address these issues. Key words: hydraulic, turbines, hydro-abrasive erosion

IEC 61362:2012 includes relevant technical data necessary to describe hydraulic turbine governing systems and to define their performance. It is aimed at unifying and thus facilitating the selection of relevant parameters in bidding specifications and technical bids. It will also serve as a basis for setting up technical guarantees. The scope of this standard is restricted to the turbine governing level. Additionally some remarks about the control loops of the plant level and about primary and secondary frequency control (see also Annex B) are made for better understanding without making a claim to be complete. Important topics covered are:
- speed, power, water level, opening and flow (discharge) control for reaction and impulse-type turbines including double regulated machines;
- means of providing actuating energy;
- safety devices for emergency shutdown.
To facilitate the setting up of specifications, this guide also includes data sheets, which are to be filled out by the customer and the supplier in the various stages of the project and the contract. Acceptance tests, specific test procedures and guarantees are outside the scope of the guide; those topics are covered by IEC 60308. This second edition cancels and replaces the first edition published in 1998. It is a technical revision. It takes into account the experience with the guide during the last decade as well as the progress in the state of the art of the underlying technologies. Keywords: Hydraulic turbine, Hydraulic turbine governing systems.

IEC 62006:2010 defines the test, the measuring methods and the contractual guarantee conditions for field acceptance tests of the generating machinery in small hydroelectric power installations. It applies to installations containing impulse or reaction turbines with unit power up to about 15 MW and reference diameter of about 3 m. The driven generator can be of synchronous or asynchronous type. This International Standard contains information about most of the tests required for acceptance of the hydraulic turbine such as safety approval tests, trial operating and reliability tests, as well for verification of cavitation, noise and vibration conditions, if required. This standard represents the typical methods used on smaller hydroelectric installations, and is divided into three classes as follows:
Class A: Default, normal test program (panel measurement), to determine the maximum output of the installation.
Class B: Recommended, extended test program, to determine the performance characteristics of the installation.
Class C: Optional, comprehensive test program, to determine the absolute efficiency of the installation.
All classes contain safety tests, trial operating tests, and reliability tests. This standard gives all necessary references for the contract in order to execute the test, evaluate, calculate and compare the result to the guarantee for all the classes A, B and C.

IEC 62097:2009 is applicable to the assessment of the efficiency and performance of prototype hydraulic machine from model test results, with consideration of scale effect including the effect of surface roughness. This document is intended to be used for the assessment of the results of contractual model tests of hydraulic machines.

IEC 60308:2005 deals with the definition and the characteristics of control systems. It is not limited to the actual controller tasks but also includes other tasks which may be assigned to a control system, such as sequence control tasks, safety and provision for the actuating energy. The following systems are included, speed, power, opening, water level and flow control for all turbine types; electronic, electrical and fluid power devices; safety devices as well as start-up and shutdown devices.

IEC 60609-1:2004 provides a basis for the formulation of guarantees applied to cavitation pitting for reaction hydraulic turbines, storage pumps and pump-turbines. It addresses the measurement and evaluation of the amount of cavitation pitting on certain specified machine components for given conditions, which are defined in the contract by output, specific hydraulic energy (E), speed, material, operation, etc. The cavitation-pitting evaluation is based on the loss of material during a given time and under accurately defined operating conditions. All wetted surfaces are considered

IEC TR 61364:1999 provides a basic nomenclature for hydraulic machinery used in hydroelectric power stations and defines their components. The contents of the corrigendum of August 2000 have been included in this copy.

IEC TR 61366-7:1998, which is a technical report, is intended to assist in the preparation of Tendering Documents and tendering proposals and in the evaluation of tenders for hydraulic machines. This part of IEC 61366 provides guidelines for storage pumps.

IEC TR 61366-1:1998, which is a technical report, is intended to assist in the preparation of Tendering Documents and tendering proposals and in the evaluation of tenders for hydraulic machines.

IEC TR 61366-3:1998, which is a technical report, is intended to assist in the preparation of Tendering documents and Tendering proposals and in the evaluation of tenders for hydraulic machines. This part of IEC 61366 provides guidelines for Pelton turbines.

IEC TR 61366-2:1998, which is a technical report, is intended to assist in the preparation of Tendering Documents and tendering proposals and in the evaluation of tenders for hydraulic machines. This part of IEC 61366 provides guidelines for Francis turbines.

IEC TR 61366-6:1998, which is a technical report, is intended to assist in the preparation of Tendering Documents and tendering proposals and in the evaluation of tenders for hydraulic machines. This part of IEC 61366 provides guidelines for pump-turbines.

IEC TR 61366-4:1998, which is a technical report, is intended to assist in the preparation of Tendering Documents and tendering proposals and in the evaluation of tenders for hydraulic machines. This part of IEC 61366 provides guidelines for Kaplan and propeller turbines.

IEC TR 61366-5:1998, which is a technical report, is intended to assist in the preparation of Tendering documents and tendering proposals and in the evaluation of tenders for hydraulic machines. This part of IEC 61366 provides guidelines for tubular turbines.

IEC 60609-2:1997 serves as a basis for the formulation of guarantees on cavitation pitting on Pelton turbine runners. It also provides a basis for the measurement and evaluation of the amount of cavitation pitting on Pelton turbine runners of a given turbine, which is defined in the contract by power, specific hydraulic energy of machine (head), rotational speed, material, operation etc. Guarantees which restrict the extent of caviation pitting and drop erosion on Pelton turbies at the end of an operating period specified in the contract are necessary when the pitting is expected in all or in some operating ranges.

Serves as a basis for the formulation of guarantees applying to cavitation pitting, and also for the measurement and evaluation of the amount of cavitation pitting on certain specified parts of a given machine.