ISO INTERNATIONAL STANDARD 21940-13 First edition 2012-03-15 Mechanical vibrationRotor balancing Part 13: Criteria and safeguards for the in-situ balancing of medium and large rotors Vibrations mécaniques Equilibrage des rotors - Partie 13: Criteres et sauvegardes relatifs a I'équilibrage in situ des rotors moyens et grands Reference number ISO 21940-13:2012(E) @ ISO 2012 ISO 21940-13:2012(E) Contents Page Foreword .iv Introduction 1 Scope 2 Normative references 3 Terms and definitions 4 In-situ balancing 4.1 General .... 4.2 Reasons for in-situ balancing 4.3 Objectives of in-situ balancing 5 Criteria for performing in-situ balancing .... 6 Safeguards .... 6.1 Safety of personnel while operating close to a rotating shaft. 6.2 Special operating envelope for in-situ balancing .. 6.3 Integrity and design of the correction masses and their attachments, 6.4 Machinery-specificsafetyimplications. 7 Measurements. 7.1 Vibration measurement equipment 7.2 Measurement errors. 7.3 Phase reference signals 8 Operational conditions 9 Reporting 9.1 General.... 9.2 Report introduction.. 9.3 Vibration measurement equipment. 9.4 9.5 Text information ... 10 AnnexA(normative)Precautionsandsafeguardsforspecificmachinetypesduringin-situ balancing.... .12 AnnexB(informative)Exampleofanin-situbalancingreportforaboilerfan<1MW. .13 Annex C (informative) Example of an in-situ balancing report for a large >5o Mw turbine generatorset .17 Bibliography 23 ii ISO 21940-13:2012(E) Foreword Iso (the International Organization for Standardization) is a worldwide federation of national standards bodies 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 InternationalElectrotechnicalCommission(iEC)onallmattersofelectrotechnicalstandardization. International Standards are drafted in accordance with the rules given in the ISO/lEC Directives, Part 2 The main task of technical committees is to prepare International Standards. Draft International Standards adopted by the technical committees are circulated to the member bodies for voting. Publication as an International Standard requires approval by at least 75 % of the member bodies casting a vote. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. sO shall not be held responsible for identifying any or all such patent rights. ISO 21940-13 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. This first edition of IsO 21940-13 cancels and replaces ISO 20806:2009, of which it constitutes a minor editorial revision. Iso 21940 consists of the following parts, under the general title Mechanical vibration Rotor balancing: Part 1: Introduction1) Part 2: Vocabulary2) Part 11: Procedures and tolerances for rotors with rigid behaviour3) 一 Part 12: Procedures and tolerances for rotors with flexible behaviour 4) Part 13: Criteria and safeguards for the in-situ balancing of medium and large rotors5) Part 14: Procedures for assessing balance errors6) 1) Revision of IsO 19499:2007, Mechanical vibration — Balancing - Guidance on the use and application of balancing standards 2) Revision of Iso 1925:2001, Mechanical vibration — Balancing — Vocabulary 3） state -Part 1: Specification and verification of balance tolerances (+ Cor.1:2005) 4) Revision of iso 11342:1998, Mechanical vibration - Methods and criteria for the mechanical balancing of flexible rotors (+ Cor.1:2000) 5) Revision of Is0 20806:2009, Mechanical vibration - Criteria and safeguards for the in-situ balancing of medium and largerotors 6) Revision of Iso 1940-2:1997, Me