EN 15495:2007

Non Destructive testing - Acoustic emission - Examination of metallic pressure equipment during proof testing - Zone location of AE sources

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 location 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 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-up by other NDT in localized zones.

Zerstörungsfreie Prüfung - Schallemission - Prüfung von metallischen Druckgeräten während der Beanspruchung - Zonenortung von Schallemissionsquellen

Diese Norm legt die Methoden zur Durchführung von Schallemissionsprüfungen (AT) bei der Abnahmeprüfung metallischer Druckgeräte unter Anwendung eines Zonenortungsverfahrens fest. Die allgemeinen Grundlagen für Schallemissionsprüfungen werden in EN 13554 beschrieben.
Eine Schallemissionsprüfung (AT) hat das Ziel, durch eine 100-%-Volumenprüfung einer Struktur akustisch aktive Zonen zu bestimmen und zu klassifizieren, die durch eine transiente Schallemission gekennzeichnet sind. Das Verfahren sollte als Ergänzung zur planaren Ortung angewendet werden. Die planare Ortung ermöglicht eine Identifizierung und Charakterisierung der Schallemissionsquellen. Die Zonenortung darf auch in den Fällen angewendet werden, in denen eine Ortung von Schallemissionsquellen durch planare Verfahren nach EN 14584 nicht möglich ist.
Dieses Verfahren identifiziert die Notwendigkeit für eine weitere Bewertung oder weitere Untersuchung der georteten Zonen mit Hilfe anderer zerstörungsfreier Prüfverfahren.

Essais non destructifs - Emission acoustique - Vérification des équipements métalliques sous pression pendant l'épreuve - Localisation par zone des sources d'EA

Neporušitveno preskušanje - Akustična emisija - Preskušanje kovinske tlačne opreme pri prevzemu - Območje namestitve senzorjev akustične emisije

General Information

• Status: Published
• Publication Date: 13-Nov-2007
• Withdrawal Date: 30-May-2008
• ICS: 17.160 - Vibrations, shock and vibration measurements
• ICS: 19.100 - Non-destructive testing
• Technical Committee: CEN/TC 138 - Non-destructive testing
• Drafting Committee: CEN/TC 138/WG 7 - Acoustic emission testing
• Current Stage: 9093 - Decision to confirm - Review Enquiry
• Start Date: 24-Sep-2024
• Completion Date: 14-Apr-2025
• Directive: 97/23/EC - Directive 97/23/EC of the European Parliament and of the Council of 29 May 1997 on the approximation of the laws of the Member States concerning pressure equipment
• Mandate: M/071 - Mandate to CEN for standardization in the field of Pressure equipment
• Ref Project: SIST EN 15495:2008 - Non Destructive testing - Acoustic emission - Examination of metallic pressure equipment during proof testing - Zone location of AE sources

EN 15495:2007 - Overview

EN 15495:2007 is a CEN standard for non‑destructive testing (NDT) by acoustic emission (AE) applied to metallic pressure equipment during proof (acceptance) testing. It specifies a zone location procedure to detect and grade volumetric areas that emit burst‑type AE during pressurisation. Zone location is intended as a supplementary or alternative method to planar AE location (see EN 14584) and is used to identify localized zones that require follow‑up inspection or other NDT.

Key topics and technical requirements

• Scope & purpose: 100% volumetric AE testing to define and grade acoustically active zones during acceptance pressure testing.
• Personnel: Testing should be performed by qualified personnel (recommendation: certification per EN 473); regulatory requirements (e.g., Directive 97/23/EC) may apply for high‑category pressure equipment.
• Instrumentation & parameters: AE systems must measure burst count, peak amplitude, duration, rise time, energy and arrival time, and log external inputs (pressure/stress). Systems should store recorded AE and provide on‑line channel/zone displays.
• Sensors & coupling: Typical monitoring frequency band is 100–300 kHz. Surface preparation and verified acoustic couplant are required; sensors may be magnetic or adhesive.
• Pre‑test measurements: Attenuation and wave velocity measurements using a Hsu‑Nielsen (pencil lead) or appropriate artificial source are required to determine maximum sensor spacing.
• Sensor spacing rule: Maximum distance between adjacent sensors = 1.5 × threshold distance (dthr), where dthr is defined from the Hsu‑Nielsen amplitude and the evaluation threshold Ae.
• Pressurisation procedure: Controlled pressurisation rates to avoid signal overlap (guidance: limits given for pneumatic/hydraulic tests), intermediate hold periods recommended (typically 5–10 min), final hold minimum 15 min.
• Zone location method: Each event is assigned to the zone of the first‑hit channel within a programmed event definition time; careful control of background noise and in‑situ verification at each sensor is required.
• Results & follow‑up: AE zone grading criteria, test stop criteria and documentation requirements are specified; zones showing significant activity must be examined by other NDT methods.

Practical applications and users

Who uses EN 15495:2007:

• NDT service providers and AE test organisations performing acceptance/proof tests
• Manufacturers and fabricators of pressure vessels, boilers, heat exchangers, piping
• Plant operators, inspection authorities and certifying bodies
• Engineers planning AE test schemes and follow‑up NDT

Why use it:

• Efficient 100% volumetric screening during pressure tests
• Identifies localized areas for targeted inspection, saving time and cost
• Provides objective criteria for AE instrumentation, sensor layout and test documentation

Related standards

• EN 13554 (general AE principles)
• EN 14584 (planar AE location for metallic pressure equipment)
• EN 13477‑1 / EN 13477‑2 (AE equipment characterisation)
• EN 1330 series (NDT terminology)
• EN 473 (personnel certification)

Keywords: EN 15495:2007, acoustic emission, AE testing, zone location, metallic pressure equipment, proof testing, non‑destructive testing, NDT, Hsu‑Nielsen, sensor spacing.

Standards Content (Sample)

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.LMHZerstörungsfreie Prüfung - Schallemissionsprüfung - Prüfung von metallischen Druckgeräten während der Abnahmeprüfung - Zonenortung von SchallemissionsquellenEssais non destructifs - Émission acoustique - Vérification des équipements métalliques sous pression pendant l'épreuve - Localisation par zone des sources d'EANon Destructive testing - Acoustic emission - Examination of metallic pressure equipment during proof testing - Zone location of AE sources19.100Neporušitveno preskušanjeNon-destructive testing17.140.20Emisija hrupa naprav in opremeNoise emitted by machines and equipmentICS:Ta slovenski standard je istoveten z:EN 15495:2007SIST EN 15495:2008en,fr,de01-april-2008SIST EN 15495:2008SLOVENSKI
STANDARD
EUROPEAN STANDARDNORME EUROPÉENNEEUROPÄISCHE NORMEN 15495November 2007ICS 17.160; 19.100 English VersionNon Destructive testing - Acoustic emission - Examination ofmetallic pressure equipment during proof testing - Zone locationof AE sourcesEssais non destructifs - Emission acoustique - Vérificationdes équipements métalliques sous pression pendantl'épreuve - Localisation par zone des sources d'EAZerstörungsfreie Prüfung - Schallemission - Prüfung vonmetallischen Druckgeräten während 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 status 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 version 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, Denmark, 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 STANDARDIZATIONCOMITÉ EUROPÉEN DE NORMALISATIONEUROPÄISCHES KOMITEE FÜR NORMUNGManagement Centre: rue de Stassart, 36
B-1050 Brussels© 2007 CENAll rights of exploitation in any form and by any means reservedworldwide for CEN national Members.Ref. No. EN 15495:2007: ESIST EN 15495:2008

Measurements.7 7.1.1 General.7 7.1.2 Wave propagation.7 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 General.11 8.2 Test stop criteria.11 8.2.1 Test stop during the initial proof loading.11 8.2.2 Test stop during subsequent loadings.11 8.3 AE zone grading criteria.11 9 Documentation.12 Bibliography.13
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 location 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 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-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) 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 emission 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 testing - 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 Qualifications
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 III and IV, the personnel must be approved by a third party organization recognized by a Member State." SIST EN 15495:2008

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 application 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 pressure 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 duration 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 extraneous 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 result is unaffected by external noise sources. The most commonly used frequency range is 100 kHz to 300 kHz. Lower frequency monitoring allo
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