1、February 2008DEUTSCHE NORM English price group 10No part of this standard may be reproduced without prior permission ofDIN Deutsches Institut fr Normung e. V., Berlin. Beuth Verlag GmbH, 10772 Berlin, Germany,has the exclusive right of sale for German Standards (DIN-Normen).ICS 19.100!$K“1409492www.
2、din.deDDIN EN 15495Non Destructive testing Acoustic emission Examination of metallic pressure equipment during proof testing Zone location of AE sourcesEnglish version of DIN EN 15495:2008-02Zerstrungsfreie Prfung Schallemission Prfung von metallischen Druckgerten whrend der Beanspruchung Zonenortun
3、g vonSchallemissionsquellenEnglische Fassung DIN EN 15495:2008-02www.beuth.deDocument comprises 15 pagesDIN EN 15495:2008-02 2 National foreword This standard has been prepared by Technical Committee CEN/TC 138 “Non-destructive testing” (Secretariat: AFNOR, France). The responsible German body invol
4、ved in its preparation was the Normenausschuss Materialprfung (Materials Testing Standards Committee), Technical Committee NA 062-08-23 AA Ultraschallprfung. EUROPEAN STANDARDNORME EUROPENNEEUROPISCHE NORMEN 15495November 2007ICS 17.160; 19.100English VersionNon Destructive testing - Acoustic emissi
5、on - Examination ofmetallic pressure equipment during proof testing - Zone locationof AE sourcesEssais non destructifs - Emission acoustique - Vrificationdes quipements mtalliques sous pression pendantlpreuve - Localisation par zone des sources dEAZerstrungsfreie Prfung - Schallemission - Prfung von
6、metallischen Druckgerten whrend der Beanspruchung -Zonenortung von SchallemissionsquellenThis European Standard was approved by CEN on 30 September 2007.CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this EuropeanStandard the statu
7、s of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such nationalstandards may be obtained on application to the CEN Management Centre or to any CEN member.This European Standard exists in three official versions (English, French, German). A ve
8、rsion in any other language made by translationunder the responsibility of a CEN member into its own language and notified to the CEN Management Centre has the same status as theofficial versions.CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Den
9、mark, Estonia, Finland,France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal,Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.EUROPEAN COMMITTEE FOR STANDARDIZATIONCOMIT EUROPEN DE NORMALISATIO
10、NEUROPISCHES KOMITEE FR NORMUNGManagement Centre: rue de Stassart, 36 B-1050 Brussels 2007 CEN All rights of exploitation in any form and by any means reservedworldwide for CEN national Members.Ref. No. EN 15495:2007: EEN 15495:2007 (E) 2 Contents Page Foreword3 1 Scope 4 2 Normative references 4 3
11、Terms and definitions .4 4 Personnel Qualifications.4 5 General5 5.1 General5 5.2 Application of load.5 5.3 Sensors.5 5.4 Zone location5 5.5 Preliminary information 6 5.6 Written instruction requirements.6 6 Instrumentation7 7 Testing 7 7.1 Pre-Test Measurements .7 7.1.1 General7 7.1.2 Wave propagat
12、ion7 7.1.3 Determination of maximum allowed sensor spacing.8 7.2 Test steps .10 7.2.1 General Guidelines 10 7.2.2 In situ verification 10 7.2.3 Background Noise .10 7.2.4 Equipment Pressurisation 10 8 Interpretation of results 11 8.1 General11 8.2 Test stop criteria11 8.2.1 Test stop during the init
13、ial proof loading11 8.2.2 Test stop during subsequent loadings .11 8.3 AE zone grading criteria .11 9 Documentation.12 Bibliography 13 DIN EN 15495:2008-02 : - EN 15495:2007 (E) 3 Foreword This document (EN 15495:2007) has been prepared by Technical Committee CEN/TC 138 “Non Destructive testing”, th
14、e secretariat of which is held by AFNOR. This European Standard shall be given the status of a national standard, either by publication of an identical text or by endorsement, at the latest by May 2008, and conflicting national standards shall be withdrawn at the latest by May 2008. Attention is dra
15、wn to the possibility that some of the elements of this document may be the subject of patent rights. CEN and/or CENELEC shall not be held responsible for identifying any or all such patent rights. According to the CEN/CENELEC Internal Regulations, the national standards organizations of the followi
16、ng countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Sloven
17、ia, Spain, Sweden, Switzerland and the United Kingdom. DIN EN 15495:2008-02 : - EN 15495:2007 (E) 4 1 Scope The purpose of this standard is to describe the methods for conducting an acoustic emission (AE) examination of metallic pressure equipment during acceptance pressure testing using a zone loca
18、tion procedure. General principles of Acoustic Emissions are described in EN 13554. The objectives of the AE testing are to provide 100 % volumetric testing to define and grade zones of the structure which are acoustically active with burst type AE. The method should be regarded as supplementary to
19、planar location. Planar location provides the source identification and characterisation. Zone location may also be applied in such cases where location of AE sources by planar location procedures according to EN 14584 is not possible. The method identifies the need for further evaluation or follow-
20、up by other NDT in localized zones. 2 Normative references The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments)
21、 applies. EN 1330-1:1998, Non destructive testing - Terminology - Part 1: List of general terms EN 1330-2:1998, Non destructive testing - Terminology - Part 2: Terms common to the non-destructive testing methods EN 1330-9:2000, Non-destructive testing - Terminology - Part 9: Terms used in acoustic e
22、mission testing EN 13477-1, Non-destructive testing - Acoustic emission - Equipment characterisation - Part 1: Equipment description EN 13477-2, Non-destructive testing - Acoustic emission - Equipment characterisation - Part 2: Verification of operating characteristic EN 14584, Non-destructive testi
23、ng - Acoustic emission - Examination of metallic pressure equipment during proof testing Planar location of AE sources 3 Terms and definitions For the purpose of this European Standard, the terms and definitions given in EN 1330-1:1998, EN 1330-2:1998 and EN 1330-9:2000 apply. 4 Personnel Qualificat
24、ions It is assumed that acoustic emission testing is performed by qualified and capable personnel. To prove this qualification, it is recommended to certify the personnel in accordance with EN 473. NOTE For pressure equipment see Directive 97/23/EC, Annex 3.1.3: “For pressure equipment in categories
25、 III and IV, the personnel must be approved by a third party organization recognized by a Member State.“ DIN EN 15495:2008-02 EN 15495:2007 (E) 5 5 General 5.1 General The main target of the AE test is to identify and monitor zones of high acoustic emission activity and intensity caused by phenomena
26、, e.g. crack growth and yielding, generated by the applied load to the equipment. The properties and structural state of the material, the type and magnitude of the applied stress and stress rate are significant factors affecting the emission. All zones showing significant activity shall be complete
27、ly evaluated by other NDT methods. Evaluation according to EN 14584 may help to reduce the area to inspect. 5.2 Application of load The application of the load to the equipment shall be made using internal pressure following the procedure specified in the relevant Product Standard. The rate of the a
28、pplication of pressure shall be established so as to avoid burst signal overlap. The pressurising system shall permit pressurisation at a steady controllable rate and shall allow the pressure to be held constant at the hold points. The pressurisation rate would not normally exceed 1 % of the test pr
29、essure per minute for pneumatic and 5 % of the test pressure per minute for the hydraulic test. The intermediate hold periods, if necessary according the AE activity or the pre-defined pressure schedule, are normally 5 min to 10 min. The final hold period at the test pressure shall have a minimum du
30、ration of 15 min. Intermediate hold periods are strongly recommended, especially if pressurisation rates exceed 0,5 % per minute for pneumatic or 2 % per minute for hydraulic tests. Prior to starting the test, all the necessary actions shall be taken to identify and to reduce potential sources of ex
31、traneous noise. Depending on the results of the initial loading, it may be required to reduce the load to working pressure or lower, followed by re-pressurisation. 5.3 Sensors The frequency range shall be chosen so that the expected AE has sufficient energy in the chosen frequency range and the test
32、 result is unaffected by external noise sources. The most commonly used frequency range is 100 kHz to 300 kHz. Lower frequency monitoring allows detection at greater distances and high frequency monitoring provides improved rejection of external noise. The equipment surface below the sensors shall b
33、e prepared to ensure the maximum coupling efficiency. The sensor couplant shall be as specified in the written test instruction. The sensors may be directly attached to the structure using magnetic devices or suitable adhesive. The effectiveness and reliability of the acoustic couplant shall be veri
34、fied. The characteristics of the type of the acoustic couplant used shall not affect the structure adversely. 5.4 Zone location Zone location assigns each event producing at least one hit to the zone of the first-hit channel. Successive hits are assumed to belong to the same event as long as they ar
35、rive within the event definition time. The event definition time is a programmable time interval, which starts with the arrival of the first-hit of an event. The event definition time is determined during test set-up using a Hsu-Nielsen or another appropriate artificial source and is set so that the
36、 source is correctly assigned only to the closest sensor. It is essential for this type of location that all noise sources are well controlled. DIN EN 15495:2008-02 EN 15495:2007 (E) 6 5.5 Preliminary information Prior to the test, the AE Test Organisation shall collect the following information: a)
37、 relevant Product Standard; b) type of equipment or structure and material characteristics and specifications; c) design- and test pressure; d) working- and test temperature; e) assembly and/or layout drawings with sufficient details of the structure; f) material specifications, including heat treat
38、ment; if applicable g) proposed pressure/stress application sequence; h) potential acoustic noise interference sources and the isolating mechanism applied; i) where possible, locations of known discontinuities and the general results of prior NDT. 5.6 Written instruction requirements The AE Test Org
39、anisation shall provide a written test instruction, which shall include but not necessarily be restricted to the following: a) Test object (description and/or drawing, including area of interest and purpose of test); b) limitations if any; c) sensor type, frequency and manufacturer; d) method of sen
40、sor attachment; e) type of acoustic couplant used; f) type of surface preparation; g) type of AE equipment used with the main characteristics and settings; h) energy measurement method to be used; i) sensor location maps representing the structure or part of it; j) description of equipment verificat
41、ion procedure; k) description of the in-situ verification (see 7.2.2); l) sequence of pressurisation; m) recorded data and recording method; n) available on-line presentation of data; o) real time evaluation criteria; p) post analysis procedure with adopted filtering technique if used; DIN EN 15495:
42、2008-02 EN 15495:2007 (E) 7 q) final report requirements; r) qualification/certification of the personnel; s) value of KZ ,( for definition see Figure 1)from the relevant Product Standard if available. 6 Instrumentation An AE system consists of sensors and equipment for signal conditioning and proce
43、ssing and for displaying and recording data according to EN 13477-1. The AE instrument shall be capable of measuring at least the following parameters on all channels: a) AE burst count; b) Burst signal peak amplitude; c) Burst signal duration; d) Burst signal rise time; e) Burst signal energy; f) A
44、rrival time; and on external inputs pressure and/or other stress parameters. To allow a real time control of the pressure equipment under test, the test instrumentation shall: Store all the acquired AE data and the external parameter(s). Provide an on-line activity vs channel display. Provide an on-
45、line activity vs zone display. Provide an on-line display of AE data and pressure. To assist the online evaluation it is recommended that the instrumentation provides data allowing real time AE noise identification. Online grading of zones is also recommended. The AE system operating characteristics
46、 shall be verified according to EN 13477-2. 7 Testing 7.1 Pre-Test Measurements 7.1.1 General The requirements listed in EN 14584 apply for a setup that uses both, planar and zone location. The following text is to be observed where planar location is not used. 7.1.2 Wave propagation Attenuation mea
47、surements shall be performed on the structure to determine the maximum sensor spacing. The measurements shall be performed with the test fluid in the pressure equipment using the Hsu-Nielsen source. If the Hsu-Nielsen source saturates the measurement chain, a lower energy artificial source shall be
48、DIN EN 15495:2008-02 EN 15495:2007 (E) 8 used up to the 20e (20 times the wall thickness) distance. The curve obtained shall be adjusted to correspond with the original Hsu-Nielsen source. The attenuation and wave velocity shall be measured using two sensors mounted in a region of the pressure equip
49、ment away from nozzles, manways, etc. The shadowing effect of nozzles and ancillary attachments shall be quantified and transmission through the test fluid shall be taken into consideration. 7.1.3 Determination of maximum allowed sensor spacing The maximum distance between adjacent sensors is 1,5 times the threshold distance dthr. The threshold distance is the distance where the amplitude of the Hsu-Nielsen source is equal to the evaluation threshold Ae. The evaluation threshold Aeis defined as the amplitude of the Hsu-Nielsen source at the di
