CLC/SR 4 - Hydraulic turbines

IEC 60308:2024 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. The significant technical changes introduced by the third edition are the adoption of parts of IEC 61362:2024 which deal with test matters and the introduction of new technical aspects.

IEC 61362:2024 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 third edition cancels and replaces the second edition published in 2012. This edition includes the following significant technical changes with respect to the previous edition: adoption of parts of IEC 60308:2005 which deal with specification matters; introduction of several new technical topics; and overall editorial revision. Keywords: Hydraulic turbine, Hydraulic turbine governing systems.

IEC 63461:2024 applies to laboratory model tests of any type of Pelton hydraulic turbine with unit power greater than 5 MW. It contains the rules governing test conduct and provides 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; - and to define the extent, content and structure of the final report. Full application of the procedures herein described is not generally justified for machines with smaller power. Nevertheless, this document can be used for such machines by agreement between the purchaser and the supplier.

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.

The purpose of this guide is to establish, in a general way, suitable procedures and tolerances for the installation of bulb turbine and generator. This guide presents a typical assembly and whenever the words "turbine" and "generator" are used in this part, it refers to bulb turbine and generator. There are many possible ways to assemble a unit. The size of the machine, the design of the machine, the layout of the powerhouse, the sequence of concreting 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. 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. The guide excludes matters of purely commercial interest, except those inextricably bound up with the conduct of installation. It also excluded to specifications of the civil works but this aspect of the work should be taken into consideration during the assembly of the units. Wherever the guide 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.

This document 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. In this document, the term "turbine" includes a pump-turbine operating as a turbine and the term "pump" includes a pump-turbine operating as a pump. 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. Moreover, additional performance data (see 4.4) can be needed for the design or the operation of the prototype of the hydraulic machine. Contrary to the requirements of Clauses 4 to 6 related to main hydraulic performance, the information of these additional data given in Clause 7 is considered only as recommendation or guidance to the user (see 7.1). It is particularly recommended that model acceptance tests be performed if the expected field conditions for acceptance tests (see IEC 60041:1991) would not allow the verification of guarantees given for the prototype machine. A transposition method taking into account the model and prototype wall surface roughness for the performance conversion on pump-turbines, Francis turbines, and axial machines is described in IEC 62097. This method requires model and prototype surface roughness data and is takes into account the shift in nED, QED and PED factors for determining the transposition of efficiency between model and prototype. However, in the case of Francis machines with semispiral casing and axial machines, the transposition method has not been fully validated due to a lack of data. In addition, IEC 62097 does not apply to storage pumps, Pelton turbines, and Dériaz. Therefore, for these and otherwise specifically agreed upon cases where hydraulically smooth flow conditions are assumed on the model and the prototype, the transposition formula and procedure given in Annex D and Annex I can be applied. Applications and limitations of both this document and IEC 62097 transposition methods are discussed in Annex E. The method for performance conversion from model to prototype needs to be clearly defined in the main hydraulic performance contract.

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 T

IEC 62097:2019 establishes the prototype hydraulic machine efficiency 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. This second edition cancels and replaces the first edition published in 2009. This edition constitutes an editorial and technical revision. This edition includes the following significant technical changes with respect to the previous edition: a) In introduction, clarifications have been brought such as addition of a sentence which declares the precedence of IEC 62097 over IEC 60193 if any mismatch is found between them b) In Clauses 3 and 4, corrections of the typographical errors c) In Clause 3: changes to be in accordance with presentation of the terms and structure of IEC 60193 (except for the water temperature) d) In Clause 4: – Deletion of the clause providing the direct step-up procedures for a whole turbine – Introduction of a global view by using turbine A and turbine B instead of model turbine, reference model turbine and prototype turbine – Move of section dealing with “surface roughness of model and prototype” in a new Clause 5 e) In Clause 5: – Introduction of additional chapters to answer comments raised at the CDV stage and to clarify the subject of surface roughness of model and prototype – Introduction of new tables for minimum recommended prototype roughness for new radial or diagonal machines and for new axial turbines – Addition of the explanation about roughness measurement of heavily rusted surface f) In Clause 7 (former Clause 6): – Introduction of a new subclause for clarifications about the assumed maximum hydraulic efficiency, hhAmax – Deletion of the requirement of mutual agreement for the application of the step-up formula for very high efficiency machines exceeding hhAmax – Clarifications of the equations from 22 to 33 by doubling the equations for suiting the “two step method g) In Clauses 6 and 7, correction of typographical errors h) In Clause 8 (former Clause 7), introduction of new figures for clarifying the “2 step” method and the alternative method i) In Annex A, modification of the flux diagram to be in compliance with IEC 60193 j) In Annex B: – Correction of the equation to obtain ΔECO – Deletion of the clause which describes the direct step-up procedures for radial flow machines k) In Annex C, deletion of the clause which describes the direct step-up procedures for axial flow machines l) In Annex D: – notes become main text – change of variable names in Subclause D.1 for clarifications m) Addition of Annex E, about comparison of IEC standards dealing with models: 60193 and 62097 n) In Annex F, clarifications of equations by adding more subscripts o) The Excel sheets attached to the standard are revised as itemized below – Deletion of the routine regarding the direct step-up procedures for a whole turbine – Deletion of the notice which requires mutual agreement when the step-up is applied to high efficiency machines exceeding hhAmax – Addition of the routine to process the normalization of test data ob

The purpose of this document 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.

NEW!IEC 62256:2017 is 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 63132-4:2020 The purpose of this this part of IEC 63132 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.

IEC 63132-3:2020: The purpose of this this part of IEC 63132 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.

IEC 63132-1:2020 The purpose of this part of IEC 63132 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 63132-2:2020: The purpose of this this part of IEC 63132 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.

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.

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.

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

This standard 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.

Specifies methods for any size and type of impulse or reaction turbine, storage pump or pump turbine. Determines whether the contract guarantees have been fulfilled and deals with the rules governing these tests as well as the methods of computing the results and the content and style of the final report.

Provides the future purchaser with information allowing him to prepare the required documents, from the call for tenders up to acceptance tests and operation of electromechanical equipment. Applies to installations having outputs of less than 5 MW and turbines with diameters less than 3 m.

This guide applies to any type of reaction or impulse turbine, as well as to any type of pump-turbine and storage pump, coupled to an electric generator or motor. It covers the field of vibration and pulsation tests referred to as standard tests.

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 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.

Provides assistance in identifying, evaluating and executing rehabilitation and performance improvement projects for hydraulic turbines, storage pumps and pump-turbines of all sizes and of the following types: Francis; Kaplan; Propeller; Pelton (turbines only); Bulb.

Provides guidelines for the application, design concepts, and implementation of computer-based control systems for hydroelectric plant automation. This standard addresses functional capabilities, performance requirements, interface requirements, hardware considerations, and operator training. Recommendations for system testing and acceptance are also included.

IEC 60193:1999 applies to laboratory models of any type of impulse or reaction hydraulic turbine, storage pump or pump-turbine. This standard 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 standard may be used for such machines by agreement between purchaser and supplier. In this standard, the term "turbine" includes a pump-turbine operating as a turbine and the term "pump" includes a pump-turbine operating as a pump. This standard excludes all matters of purely commercial interest, except those inextricably bound up with the conduct of the tests. This standard 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. The main objectives of this standard 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, which fall within the scope of this standard, 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.

EN following parallel vote * Superseded by EN 61362:2012