Non-destructive testing. Methodology for qualification of non-destructive tests

CEN/TR 14748:2004

Non-destructive testing
Methodology for qualification of non-destructive tests

EUROPEAN COMMITTEE FOR STANDARDIZATION

EUROPAISCHES KOMITEE FOR NORMUNG

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

Contents
Foreword 3
1 Scope 5
2 Normative references 6
3 Terms and definitions 6
4 General principles 8
5 Qualification phases, steps and responsibilities 8
Annex A (informative) Elements of NDT qualification process 14
A.1 Practical assessment 14
A.2 T echnical justification 14
A.3 Qualification of NDT procedure 15
A.4 Training of NDT personnel 15
A.5 Qualification feedback 15
Annex В? (informative) Input information to be made available prior to NDT qualification 16Foreword
This document (CEN/TR 14748:2004) has been prepared by Technical Committee CEN/TC 138 “Non-destructive testing”, the secretariat of which is held by AFNOR. Introduction
Non-destructive tests (NDT) are typically one of a great number of activities within the quality assurance at manufacture or during maintenance of industrial products, where the objective is to ensure a defined or agreed product quality.
This is especially the case if the non-destructive tests are carried out according to standards or other accepted technical codes.
Qualification of a non-destructive test may be necessary in the case of non standardised NDT or if the NDT does not fully comply with the appropriate standard to ensure a defined or agreed product-quality. The objective of qualification is to provide confidence in the non-destructive test itself and also in its continued performance. Nondestructive tests, however, will not in themselves provide statements on product safety or on the lifetime of a product.
Qualification should also be considered when there are reasons to provide additional assurance that the NDT can meet the inspection requirements. 1 Scope
This document sets out basic principles and provides recommendations and general guidelines for carrying out qualification of non-destructive tests.
The document deals with methods for qualifying non-destructive tests to determine whether they are capable of attaining their objectives. It applies to all aspects of tests which influence their effectiveness.
The parties involved decide in their own responsibility on the need for a qualification of a non-destructive test. This includes identification of the qualification-team and its technical competence.
There may be a need for qualification when there is a deviation from a European NDT Standard, or when new techniques or methods are to be implemented for which there are no European Standards. Where there is a European NDT Standard which applies, there is no need for qualification.
Table 1 summarises when qualification is required.

Table 1 — Need for qualification

This document is relevant to any non-destructive testing method and is therefore written in general terms, setting out the principles that apply. It does not, in itself, constitute a specification for NDT qualification for a specific component but is intended to be used as a basis for development of such specifications.
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 473, Non-destructive testing - Qualification and certification of NDT personnel - General principles’
3 Terms and definitions
For the purpose of this document, the following terms and definitions apply.
3.1
blind trial
trial in which those applying the non-destructive test to test pieces have no knowledge of the position of the discontinuities in those test pieces (Type and orientation according to the NDT procedure)
3.2
essential parameters
parameters of the non-destructive tests, of the component and of the discontinuities that the test is intended to detect or to size, which significantly affect the outcome of the test; the boundaries between which these parameters can vary without significantly affecting the test are specified in the technical justification and/or NDT procedure as appropriate
3.3
NDT equipment
means by which NDT is implemented. This includes both hardware and software
3.4
NDT method
discipline applying a physical principle in non-destructive testing (for example: eddy current test method)
3.5
NDT procedure
written description of how to apply a NDT technique to a specific test, including all essential parameters and precautions to be observed. An NDT procedure can involve the application of more than one NDT method or technique
3.6
NDT qualification
confirmation by examination and/or provision of objective evidence that the particular requirements for a sped' use of NDT are fulfilled. NDT qualification is one part of the whole qualification process
3.7
NDT system
all parts of the non-destructive test including equipment, NDT procedure and personnel, which can influence outcome and quality of the NDT
3.8
NDT technique
specific way in which the NDT method is utilised
NOTE For ultrasonic testing it may include, for example, pulse echo, tandem, TOFD, focused probes and so on, or combination of these which has been adopted.
3.9
open trial
trial in which those applying the non-destructive test to test pieces have specific knowledge of the discontinuities 1 those test pieces
3.10
parties involved .
parties involved are usually producer, supplier and/or purchaser who take responsibility for an industrial prod^c during manufacturing and/or service. In some cases, it may also include manufacturer, user, design departm en ■? regulatory body, notified body, and/or third party body
3.11
physical reasoning
compilation of the detailed reasons for the selection of a particular non-destructive test
3.12
practical assessment
assessment of a non-destructive test by applying it to test pieces or to components containing natural defects
3.13
qualification dossier
assembly of all the information relevant to the qualification process
3.14
qualification process
process of demonstrating whether a specific NDT application is capable of fulfilling specific requirements
3.15
qualification programme
orderly list of actions to be carried out for the NDT qualification
3.16
qualification statement —
document issued under the rules of a qualification system indicating that adequate confidence is provided that procedures, equipment and personnel or any combination of these are capable, for a specific test, of achieving stated objectives of the test
3.17
qualification team
person(s) that plan, conduct and accept NDT qualification, who are technically competent and acceptable to t^ 3.18
technical justification
collection of all the information which provides evidence about the capability of an NDT technique as applied to a specific component
NOTE: It may include, for example, physical reasoning, mathematical modelling, results from test piece trials, field NDT results or experimental studies as appropriate.
3.19
test piece
example or a simulation of the component for which the non-destructive test is to be qualified which will, as appropriate, replicate size, geometry, material properties and defective condition(s) to be encountered on site.
4 General principles
Qualification of a non-destructive test may require assessment of an NDT system, composed of any combination of NDT procedure, equipment and specific training of personnel.
This qualification consists of one of the following items:
a) practical assessment (blind or open trial) conducted on the component or simplified or representative test pieces resembling the component to be inspected;
b) technical justification, which involves assembling all evidence on the effectiveness of the test including previous experience of its application, experimental studies, mathematical modelling, physical reasoning etc;
c) appropriate mix of practical assessment and technical justification.
The appropriate mix of the above sources of evidence has to be judged separately for each particular case. The use of technical justification should reduce practical assessment exercises. In some cases, it may be possible to qualify NDT without any practical trials.
Further information on the concepts of practical assessment and technical justification is given in Annex A.
5 Qualification phases, steps and responsibilities
The qualification phases, steps and responsibilities, which may be taken to qualify NDT, are shown in Table 2. The table also gives a reference to the relevant subclauses of this document that deal in more detail with each of the steps. Within each of the five qualification phases, Table 2 does not necessarily indicate the order in which the steps are taken.

Table 2: Qualification phases, steps and responsibilities
Phase Step-№? I Responsibility Reference Phase 1: Prior to NDT qualification Subclause 5.1 Make available all required input information concerning component, relevant discontinuities, specific NDT objectives 1 Parties involved subclause 5.1 Define the NDT qualification objectives and which kind of results the qualification is aimed at 2 Parties involved subclause 5.1 Define the field of application of the NDT qualification, e.g. oil industry, power industry, etc 3 Parties involved subclause 5.1 Identify the qualification team 4 Parties involved subclause 5.1 Prepare the draft NDT procedure to be qualified, if necessary
Assemble the input data for the technical justification as appropriate 5 Parties involved, qualification team as appropriate subclause 5.1 Phase 2: Planning of NDT qualification Subclause 5.2 Prepare the qualification programme 6 Qualification team subclause 5.2 Agree on qualification programme 7 Parties involved, qualification team as appropriate subclause 5.2 Phase 3: Conducting NDT qualification Subclause 5.3 Conduct qualifica