Bsi bs en 01593 1999 (2004)

www bzfxw com BRITISH STANDARD BS EN 1593 1999 Incorporating Amendment No 1 Non destructive testing — Leak testing — Bubble emission techniques The European Standard EN 1593 1999, with the incorporati[.]

BRITISH STANDARD BS EN

1593:1999

Incorporating Amendment No 1

Non-destructive

testing —

Leak testing — Bubble

emission techniques

The European Standard EN 1593:1999, with the incorporation of

amendment A1:2003 has the status of a British Standard

ICS 19.100

12&23<,1*:,7+287%6,3(50,66,21(;&(37$63(50,77('%<&23<5,*+7/$:

This British Standard, having

been prepared under the

direction of the Engineering

Sector Committee, was

published under the authority

of the Standards Committee

and comes into effect on

15 December 1999

© BSI 1 March 2004

ISBN 0 580 35166 1

This British Standard is the official English language version of EN 1593:1999, including amendment A1:2003.

The UK participation in its preparation was entrusted to Technical Committee WEE/46, Non-destructive testing, which has the responsibility to:

A list of organizations represented on this committee can be obtained on request to its secretary.

Cross-references

The British Standards which implement international or European

publications referred to in this document may be found in the BSI Catalogue

under the section entitled “International Standards Correspondence Index”, or

by using the “Search” facility of the BSI Electronic Catalogue or of British

Standards Online.

This publication does not purport to include all the necessary provisions of a contract Users are responsible for its correct application.

Compliance with a British Standard does not of itself confer immunity from legal obligations.

— aid enquirers to understand the text;

— present to the responsible international/European committee any enquiries on the interpretation, or proposals for change, and keep the

UK interests informed;

— monitor related international and European developments and promulgate them in the UK.

Summary of pages

This document comprises a front cover, an inside front cover, the EN title page, pages 2 to 11 and a back cover.

The BSI copyright notice displayed in this document indicates when the document was last issued.

Amendments issued since publication

14967 1 March 2004 Modification to Foreword page and

deletion of Annex ZA

EUROPEAN STANDARD

NORME EUROPÉENNE

EUROPÄISCHE NORM

EN 1593

September 1999

+ A1

December 2003

ICS 19.100

English version

Non-destructive testing – Leak testing – Bubble emission

techniques

(includes amendment A1:2003)

Essais non destructifs – Contrôle d’étanchéité – Contrôle à

la bulle (inclut l’amendement A!:2003)

Zerstörungsfreie Prüfung – Dichtheitsprüfung –

Blasenprüfverfahren (enthält Änderung A!:2003)

This European Standard was approved by CEN on 16 August 1999, and amendment A1 was approved by CEN on 20 November 2003 CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration Up-to-date lists and bibliographical references concerning such national standards 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 translation under the responsibility of a CEN member into its own language and notified to the Management Centre has the same status as the official versions

CEN members are the national standards bodies of Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Luxembourg, Malta, Netherlands, Norway, Portugal, Slovakia, Spain, Sweden, Switzerland and United Kingdom

EUROPEAN COMMITTEE FOR STANDARDIZATION

C O M I T É E U R O P É E N D E N O R M A L I S A T I O N

E U R O P Ä I S C H E S K O M I T E E FÜ R N O R M U N G

Management Centre: rue de Stassart, 36 B-1050 Brussels

© 1999 CEN All rights of exploitation in any form and by any means reserved

worldwide for CEN national Members

Ref No EN 1593:1999 + A1:2003 E

Contents

Page

Page 3

EN 1593:1999

Foreword

This European Standard has been prepared by Technical Committee CEN/TC 138 "Non-destructive testing", the 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 March 2000, and conflicting national standards shall be withdrawn at the latest by March 2000

This document has been prepared under a mandate given to CEN by the European

Commission and the European Free Trade Association

According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries 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

Foreword to amendment A1

This document EN 1593:1999/A1:2003 has been prepared by Technical Committee

CEN/TC 138 "Non-destructive testing", the secretariat of which is held by AFNOR

This Amendment to the European Standard EN 1593:1999 shall be given the status of a national standard, either by publication of an identical text or by endorsement, at the latest by June 2004, and conflicting national standards shall be withdrawn at the latest by June 2004 This document has been prepared under a mandate given to CEN by the European

Commission and the European Free Trade Association

According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Luxembourg, Malta, Netherlands, Norway, Portugal, Slovakia, Spain, Sweden,

Switzerland and the United Kingdom

1 Scope

This European Standard describes procedures for the detection and location of leaks by the bubble emission techniques The sensitivity depends on techniques and materials used Two techniques are described:

a) immersion technique: quantitative measurements can be made using this

procedure with particular devices (see informative annex A)

b) liquid application technique

This standard can be used for equipment which can be evacuated or pressurised

2 Normative references

This standard incorporates by dated or undated reference, provisions from other publications These normative references are cited at the appropriate places in the text and the publications are listed hereafter For dated references, subsequent amendments to or revisions of any of these publications apply to this standard only when incorporated in it by amendment or

revision For undated references the latest edition of the publication referred to applies

tightness testing

technique selection

3 Definitions

For the purposes of this standard, the definitions given in EN 1330-8 apply

4 Personnel qualification

It is assumed that leak testing is performed by qualified and capable personnel In order to prove this qualification, it is recommended to certify the personnel in accordance with EN 473

or equivalent

5 Principle

The techniques involve the establishment of a pressure difference across the object wall and the observation of bubble formation in a liquid medium located on the low pressure side The minimum detectable leakage rate by these techniques depends on the pressure difference, the gas and the liquid used for testing

Page 5

EN 1593:1999

6 General requirements

The position of the leak shall be visible directly or indirectly in order to check if it is a real leak

in the area to be tested

6.1 Gases

The test gas is normally air Inert gases may however be used When inert gases are used, the safety aspects of oxygen deficient atmospheres shall be considered

6.2 Pressure limits

Verification shall be obtained that the object has been designed to withstand the test pressure difference The test conditions shall be such that the object is not permanently deformed nor should the test be a hazard for the operators

6.3 Stabilization time (for immersion technique)

Prior to examination, the test pressure in the sealed object shall be maintained for a time appropriate for the establishment of bubble emission For small leaks, this may take several minutes

6.4 Surface temperature

Normally the temperature of that part of the surface of the object that is to be examined shall

heating or cooling is permitted provided the temperatures remain within this range Where it is impractical to comply with the foregoing temperature limitations, other temperatures may be used provided that the procedure has been shown to be suitable

6.5 Direct visual examination

Direct visual examination is usually made when the surface can be viewed directly at a

distance not exceeding 0,6 m at an angle not less than 1/6 rad (30 degrees) Mirrors may be used to improve the angle of vision, and aids such as magnifying lenses may also be used to assist examinations The component or area under immediate examination should be

illuminated, if necessary with a flashlight or other auxiliary lighting, to attain an appropriate light level Recommended illumination is 350 lux to 500 lux

6.6 Indirect visual examination

In some cases indirect visual examination may have to be substituted for direct examination This may involve the use of visual aids such as mirrors, endoscopes, telescopes or other suitable instruments These should have a resolution capability at least equivalent to that obtainable by a direct visual observation

The test object should be thoroughly cleaned

Surface contamination, e.g grease, rust, weld slag, etc., on the test object surface can mask

or cause bubble formation and give a false indication

Contaminated detection liquid or one that foams spontaneously on application may cause spurious surface bubbles on the test object and should be avoided

8 Immersion technique

8.1 General

This technique (see EN 1779:1999, table A.2, technique C.1) is applicable to the examination

of objects that can be completely immersed in a container of detection liquid, including sealed

or temporary sealed ones during the test, and the pressure in any part of the test object shall

be greater than in the liquid and should be known

8.2 Variations

8.2.1 Direct pressurization of the object

The object is pressurized and placed in the selected detection liquid The surface, after the stabilization (soak) time, is observed for a minimum period which depends on the test

specification (e.g allowable leakage rate, pressure, liquid type) and the type of test object A stream of bubbles originating from any isolated point shall be interpreted as a leakage

8.2.2 Use of detection liquid at elevated temperature

If the object is sealed close to an atmospheric pressure, its internal pressure can be increased

by placing it in the detection liquid held at an elevated temperature The test time depends on the internal volume of the object and shall be sufficient to allow a suitable pressure increase within the object (according to the equation of state of ideal gases) The efficiency of this test can be increased by introducing, before sealing, a liquid with a boiling point lower than the test temperature

A stream of bubbles originating from any isolated point shall be interpreted as a leakage

8.2.3 Use of vacuum

The sealed object is completely immersed in the detection liquid in a vacuum chamber, with a viewing port (see figure 1) Pressure in the vacuum chamber is reduced to a level which depends on the detection liquid, to prevent excessive loss of liquid by evaporation

A series of bubbles originating from any isolated point shall be interpreted as a leakage

Page 7

EN 1593:1999

8.3 Detection liquids used in immersion technique

Various liquids may be used for the detection, provided that they are transparent enough and

do not adversely affect the objects being tested Commonly-used are water with suitable wetting agents, ethylene glycol or low-viscosity mineral oil

An analysis of the detection fluid should be carried out to determine the presence of

undesirable components, such chlorine, fluorine, sulfur, etc

Mineral oil is the most suitable liquid for the vacuum technique, but degreasing of the test object may be necessary

When the vacuum technique is used the liquid should be previously degassed

9 Liquid application technique

9.1 General

This technique involves the application of a liquid film to the surface of the test object

It is applicable to any object in which a pressure differential can be created across the

boundary to be examined This technique may be used for open components and for those objects for which immersion would be impractical

9.2 Variations

9.2.1 Direct pressurization of the object

This procedure (see EN 1779:1999, table A.2, technique C.2) refers to objects that can be pressurized A suitable liquid surfactant is applied on the low pressure side (by brush, spray or other methods)

Afterwards, wait for a sufficiently long inspection time to realise even slow production of foam from small leaks From large leaks the test fluid may be blown away and no foaming may occur

A growing foam originating from any isolated point shall be interpreted as a leakage

9.2.2 Use of vacuum for unpressurized (open) objects

This technique (See EN 1779:1999, table A.2, technique C.3) is suitable for open objects e.g unfinished parts, objects not accessible on the rear side or large objects for which the

pressurization is impractical The method involves the attachment of a suitable vacuum box with a top viewing port to those parts of the test object under investigation, the latter having been previously covered with surfactant liquid (see figure 2)

Care shall be taken in the design and construction of the vacuum box to prevent implosion

pump Care should be taken in the sealing of the vacuum box, particularly on the weld

reinforcement (crown) The pressure should be progressively reduced until the specified test pressure, e.g 20 kPa or 50 kPa, has been reached This value has to be maintained for the specified time, at least 30 s A minimum vacuum box overlap of 50 mm for adjacent test areas

is necessary

9.3 Detection liquids used in liquid application technique

Suitable surfactant liquids shall be used They shall be nonvolatile (they shall not dry at test temperature during the inspection time), viscous and shall not foam under reduced pressure Commercial fluids not specific for leak testing shall not be used unless their suitability has been previously demonstrated on that type of test, by comparison with the characters of a specific bubble test fluid In the presence of gas leakage however the bubbles which form should persist for the duration of the test

For vertical surface tests, the test fluid viscosity may be increased, if necessary, by suitable methods

The compatibility of the test fluids with the materials of the test objects has to be ensured

10 Test report

If procedures require a test report, this shall include the following information:

a) technique used;

b) internal and/or low side pressure;

c) liquid type;

d) test temperature;

e) soaking time;

f) duration of the test;

g) operator certification;

h) test results