EN 13185:2001
(Main)Non-destructive testing - Leak testing - Tracer gas method
Non-destructive testing - Leak testing - Tracer gas method
This standard describes the techniques to be applied for the detection of a leak, using a tracer gas and a tracer gas specific leak detector.
Zerstörungsfreie Prüfung - Dichtheitsprüfung - Prüfgasverfahren
1 Anwendungsbereich
Diese Europäische Norm legt die Verfahren des Lecknachweises bei Benutzung eines Prüfgases und eines
prüfgasspezifischen Leckdetektors fest.
Essais non destructifs - Contrôle d'étanchéité - Méthode par gaz traceur
La présente norme européenne décrit les techniques à appliquer pour la détection d'une fuite à l'aide d'un gaz traceur et d'un détecteur de fuite spécifique au gaz traceur utilisé.
Neporušitveno preskušanje - Preskušanje tesnosti - Metoda slednega plina
General Information
Relations
Standards Content (Sample)
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.Neporušitveno preskušanje - Preskušanje tesnosti - Metoda slednega plinaZerstörungsfreie Prüfung - Dichtheitsprüfung - PrüfgasverfahrenEssais non destructifs - Contrôle d'étanchéité - Méthode par gaz traceurNon-destructive testing - Leak testing - Tracer gas method19.100Neporušitveno preskušanjeNon-destructive testingICS:Ta slovenski standard je istoveten z:EN 13185:2001SIST EN 13185:2002en01-junij-2002SIST EN 13185:2002SLOVENSKI
STANDARD
EUROPEAN STANDARDNORME EUROPÉENNEEUROPÄISCHE NORMEN 13185March 2001ICS 19.100English versionNon-destructive testing - Leak testing - Tracer gas methodEssais non destructifs - Contrôle d'étanchéité - Méthodepar gaz traceurZerstörungsfreie Prüfung - Dichtheitsprüfung -PrüfgasverfahrenThis European Standard was approved by CEN on 18 January 2001.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 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 Management Centre has the same status as the officialversions.CEN members are the national standards bodies of Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece,Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom.EUROPEAN COMMITTEE FOR STANDARDIZATIONCOMITÉ EUROPÉEN DE NORMALISATIONEUROPÄISCHES KOMITEE FÜR NORMUNGManagement Centre: rue de Stassart, 36
B-1050 Brussels© 2001 CENAll rights of exploitation in any form and by any means reservedworldwide for CEN national Members.Ref. No. EN 13185:2001 ESIST EN 13185:2002
Page 2EN 13185:2001ContentsPageForeword.31Scope.42Normative references.43Terms and definitions.44Personnel qualification.45Principles of detection.46Generation and detection of tracer gas flow.56.1Tracer gas flows into the object ( Group A techniques ).56.2Tracer gas flows out of the object (Group B techniques):.57Apparatus - see prEN 13625:2001.58Object preparation.59Group A techniques, tracer gas flowing into the object.69.1Initial system set up procedure.69.2Vacuum technique (total) test procedure
(A.1).79.3Vacuum technique (partial) test procedure ( A2 ).89.4Vacuum technique (local) test procedure (A.3).810Group B techniques, tracer gas flowing out of object.810.1Initial system set up procedure.910.2Ammonia
test procedure (B.1).1010.3Vacuum box test procedure (B.2.1, B.2.2).1110.4Accumulation technique procedures (B.3, B.6).1210.5Sniffing test (B.4).1410.6Pressure evacuation procedure ( B.5).1411Test report.16Annex A (informative)
Accumulation technique : calibration leak connected to enclosure of unknownvolume.17Annex ZA (informative)
Clauses of this European Standard addressing essential requirements or otherprovisions of EU Directives.18SIST EN 13185:2002
Page 3EN 13185:2001ForewordThis European Standard has been prepared by Technical Committee CEN/TC 138 "Non-destructive testing", thesecretariat 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 orby endorsement, at the latest by September 2001, and conflicting national standards shall be withdrawn at thelatest by September 2001.This European Standard has been prepared under a mandate given to CEN by the European Commission and theEuropean Free Trade Association, and supports essential requirements of EU Directive(s).For relationship with EU Directive(s), see informative Annex ZA, which is an integral part of this standard.Annex A is informative.According to the CEN/CENELEC Internal Regulations, the national standards organizations of the followingcountries are bound to implement this European Standard: Austria, Belgium, Czech Republic, Denmark, Finland,France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden,Switzerland and the United Kingdom.SIST EN 13185:2002
Page 4EN 13185:20011 ScopeThis standard describes the techniques to be applied for the detection of a leak, using a tracer gas and a tracergas specific leak detector.2 Normative referencesThis European Standard incorporates by dated or undated reference, provisions from other publications. Thesenormative references are cited at the appropriate places in the text and the publications are listed hereafter. Fordated references, subsequent amendments to or revisions of any of these publications apply to this EuropeanStandard only when incorporated in it by amendment or revision. For undated references the latest edition of thepublication referred to applies (including amendments).EN 473
Qualification and certification of NDT personnel - General principlesEN 1330 - 8
Non destructive testing – Terminology -Part 8 : Terms used in leak tightness testingEN 1779
Non destructive testing -Leak Testing – Criteria for method and technique selectionprEN 13192:2001 Non destructive testing -Leak test – Calibration of gaseous reference leaksprEN 13625:2001 Non destructive testing -Leak test - Guide to the selection of instrumentation for themeasurement of gas leakage.3 Terms and definitionsFor the purposes of this European Standard, the terms and definitions given in EN 1330-8 apply.4 Personnel qualificationIt is assumed that leak testing is performed by qualified and capable personnel. In order to provide thisqualification, it is recommended to certify the personnel in accordance with EN 473 or equivalent.NOTEFor pressure equipment see directive 97/23/EC (Annex I, paragraph 3.1.3) : "For pressure equipment in categoriesIII and IV, the personnel must be approved by a third party organization recognized by a Member State"5 Principles of detectionA partial pressure difference of tracer gas is created across the boundary of the object to be tested. The tracergas, having passed through the leak, is revealed by its physical or chemical properties.
Chemical detection isgenerally based on reactions that cause a local colour change (the object surface shall therefore be visible).Detection based on physical properties usually involves a sensor, for example: a mass spectrometer, tuned for the specific tracer gas used
(generally helium-4 ); an alkali ion diode, for halogen gas, and electron-capture equipment (i.e. for SF6 ); a Pirani gauge, for
tracer gas with thermal conductivity different from that of the ambient atmosphere; a photometer, with band-pass filter in the frequency range of the tracer gas absorption or emission.These types of detection generally give an electrical signal which varies with the tracer gas partial pressure.SIST EN 13185:2002
Page 5EN 13185:20016 Generation and detection of tracer gas flowTwo basic techniques are used - see EN 17796.1 Tracer gas flows into the object ( Group A techniques )A pressure difference across the wall is obtained either by evacuation of the object, e.g. through a connectionor by placing it in a pressurized chamber. Usually the test object is evacuated.
Tracer gas is then applied tothe external surface using a probe jet or by enclosing the object (totally or partially ) in a hood or chamber filledwith the tracer gas. Tracer gas leakage into the test object is detected by a sensor within or connected to theinternal volume.6.2 Tracer gas flows out of the object (Group B techniques):The object is filled with a tracer gas. A pressure difference across the wall is obtained either by pressurizationof the object, e.g. through a connection or by placing it in a vacuum chamber. The tracer gas is collected onthe outside surface by a sampling probe or by
accumulation into a hood or chamber. Tracer gas can also bedetected by chemical reactions.A special technique (bombing ) may also be used. This involves pressurization of a sealed object to forcetracer gas into its internal cavities, if a leak exists. The object is then placed in a vacuum chamber andescaping tracer gas is detected (usually this procedure is used only with helium- 4).This method is applicable to specimens with small free internal volumes (in the order of a few cubiccentimetres).7 Apparatus - see prEN 13625:2001The test apparatus can include part or all of the following:7.1Leak detector or chemical reagents able to detect the selected tracer
gas7.2Calibration leaks, calibrated for discharge into vacuum and/or against atmospheric pressure ; refer toprEN 13192:2001.7.3Pressure and
temperature gauges7.4Tracer gas or certified gas mixture.7.5Auxiliary vacuum systems7.6Hood, vacuum or pressurizing chamber, jet or sampling probe7.7Purging dry gas, liquid nitrogen (for cold trap), if necessary.7.8Equipment for tracer gas treatment-recovery7.9Equipment for test area ventilation7.10Data recording equipment8 Object preparationThe object to be tested shall be adequately cleaned, degreased and dried. Openings and apertures which arenot involved in the test must be closed with test seals, e.g. plugs, welding, suitable material
and gaskets.Whenever possible, testing should be carried before plating, painting or the application of ultrasonic couplant.SIST EN 13185:2002
Page 6EN 13185:2001If the object has to be evacuated, the presence of porous or plastic materials should be avoided. This helps toavoid spurious indications
(virtual leaks), and shortens the clean up time.The connections between the object, the pumping system, the leak detector or (LD) and the calibration leaksused shall be suitable and checked for tightness.9 Group A techniques, tracer gas flowing into the object.These techniques are applicable to an object that can be evacuated or withstand an external test pressure.The tracer gas is applied on the outer surface of the object and the LD is connected to the internal volume. Ifthe LD is of Mass Spectrometer type (MLSD), the pumping system of the MSLD itself can be used to evacuatedirectly small items under test.Larger objects need an auxiliary pumping system. In this case, the loss of sensitivity shall be considered, asonly part of the tracer gas will enter the LD.Three techniques may be used - refer to EN 1779:- Vacuum technique (Total) – A.1The object, placed in an enclosure (a bag or a chamber), is evacuated and connected to the detector. Theenclosure is then filled with the tracer gas or a gas mixture containing the tracer gas. This technique allows theevaluation of the leakage rate but does not permit precise location of the leaks.When the purpose of the leak testing is the determination of the acceptability of the test object against aspecified leakage rate, only the integral technique shall be used. In this case, the tracer gas concentration,pressure and temperature shall be measured and the homogeneity of the gas mixture shall be ensured.Further the enclosure shall be gas-tight and, preferably, rigid.- Vacuum technique (Partial) – A.2The object to be tested is evacuated and connected to the detector. Suspect areas are then covered by asuitable gas-tight enclosure filled with tracer gas.- Vacuum technique (Local) – A.3The object to be tested is evacuated and connected to the detector. Suspect areas on the external surface ofthe object are sprayed with tracer gas. Leaks can be localised using this technique but it is not possible tomeasure the total leakage rate.9.1 Initial system set up procedure9.1.1The LD shall be adjusted in accordance with manufacturer's instructions, using a calibration leak (ifrequired the leak shall be "standard"). If a MSLD is used, a leak for discharge to vacuum has to be connecteddirectly to the inlet of the LD, or the built-in leak for the calibration is to be used.9.1.2The object is connected to the
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