Страница 2: ДСТУ CEN/TR 14748:2015. Non-destructive testing. Methodology for qualification of non-destructive tests (62592)

All the decision steps related to combination and interpretation of the results of the different techniques allowing one to arrive at the final result are documented.

on test pieces is in conformity with the written procedures and data gathered during blind trials are not removed from the qualification site.

provides as much feedback as possible on the reasons for failure. The parties involved review the feedback provided and decide on appropriate action.

The qualification dossier will be assembled by the qualification team. It contains all information related to the whole process of NDT qualification and comprises the following, if applicable:

1. input information;

2. draft NDT procedure;

3. technical justification;

4. qualification programme;

5. test reports and examination papers when produced during the NDT qualification process;

6. identification of the equipment used for the qualification;

7. conclusion(s) of the qualification, including results of all assessments and practical trials, and the range of essential parameters, including those concerning the equipment, for which the qualification is valid;

8. qualified NDT procedure (see 5.5.1);

9. qualification statements;

10. documents that relate to any changes to the NDT objectives or NDT system, including feedback gained during the qualification process.

The qualification dossier is archived and remains accessible if required.

of document) to the parties involved. The statement identifies the NDT procedure and/or equipment which were used for qualification, and the criteria used for its assessment.

In general, EN 473 applies to the qualification and certification of personnel.

Any job specific training to be included in the qualification process should be agreed between the parties involved (see A.4).

Where NDT qualification has not been successful, the qualification team issues a statement (or other form of document) to the parties involved.

The format of any qualification statement to be issued is a matter to be agreed between the parties involved.

Based on the results of the qualification, a qualified NDT procedure is established or confirmed and is added to the qualification dossier.

If feedback from experience shows evidence which deviates from that obtained during NDT qualification, then the qualification dossier should be updated by the parties involved.Annex A

(informative)
Elements of NDT qualification process

Whatever the detailed approach followed, the qualification should be performed using the appropriate mix of technical justification and practical assessment on test pieces and/or available components.

For example, use of technical justification could minimise or remove the need for practical assessment where suitable evidence exists. Alternatively, the qualification may depend entirely on practical assessment if a satisfactory technical justification cannot be constructed.

A.1 Practical assessment

Practical assessment involves test pieces replicating the component or a part of the component under test. The test piece is designed to contain discontinuities and/or geometrical features of appropriate orientation, dimensions and positions.

Simpler test pieces can be used but the results need to be extrapolated to the real situation using arguments in the technical justification.

The qualification team assesses the use of the discontinuities to be incorporated in the test pieces relative to the discontinuities postulated.

A.2 Technical justification

The purpose of the technical justification is:

1. to cite evidence to support the claimed capability of the NDT system;

2. to complement and to generalise, if necessary, any practical trials results by demonstrating that the results obtained on the specific discontinuities in the test pieces would equally well have been obtained for other possible discontinuities;

3. to provide a sound technical basis for the design of test pieces;

4. to provide a technical basis for the selection of the essential parameters of the NDT system and their valid range.

The technical justification comprises a mixture of experimental evidence and theoretical assessment as appropriate. The evidence cited in the technical justification can be either pre-existing evidence (e.g., from published literature or reports) or new evidence specifically obtained for the NDT being qualified.

A technical justification could include:

1. measurements on practice test pieces;

2. physical reasoning;

3. feedback from field experience;

4. previous qualifications;

5. relevant round robin trials;

6. feasibility studies and industrialisation trials;

7. mathematical models;

8. laboratory studies;

9. description of the type of equipment by the manufacturer;

10. experimental development results;

11. results collected on open trial test pieces.

A.3 Qualification of NDT procedure

Where required an NDT procedure can be qualified by technical justification, open trials or both.

Where the NDT procedure or an item of the equipment does not fall within the scope of an appropriate standard or specification, or the parties involved do not want to use existing standards or specifications, the qualification includes open trials or other experimental tests designed to measure the essential parameters of the equipment. In this case the NDT procedure contains the essential parameters and specifies allowable values and tolerances.

Qualification of the NDT procedure using technical justification involves the following:

1. assessment of the technical adequacy of the NDT procedure;

2. analysis of the essential parameters;

3. checking that all the NDT procedure essential parameters, which affect the outcome of the NDT significantly, and the range within which they can vary are specified and that they are, if necessary, considered in the practical trials;

4. checking that the NDT procedures are written in a sufficiently systematic and unambiguous way that their application is reproducible.

Where a sufficient demonstration of its adequacy through technical justification is not possible, open trials or other experimental tests are performed for the NDT procedure.

A.4 Training of NDT personnel

Personnel, using qualified NDT procedures and equipment, should be trained through one or both of the following:

1. training and certification according to EN 473 or an equivalent standard at an appropriate level in the relevant industrial sector;

2. job specific training and assessment;

Where specific arrangements for training NDT personnel are proposed, the qualification team satisfies itself that these arrangements are appropriate and ensures that they are specified in the NDT procedure.

Depending on the complexity of the non-destructive tests it can be necessary for only designated NDT personnel to be trained.

A.5 Qualification feedback

The qualification team may provide advice on meeting the requirements of the actual tests or on technology transfer in the light of knowledge or experience gained through the qualification process.

Annex В
(informative)
Input information to be made available prior to NDT qualification

The qualification team should agree on the objectives of the NDT qualification with the parties involved. The items discussed in this annex, which are an essential part of the input information, should be available to the qualification team before qualification commences and comprise the initial part of the qualification dossier. If not immediately available, the qualification team should agree with the parties involved on the steps to be taken to ensure the information necessary is available before qualification commences.

The input information refers to:

Position, depth and length sizing: if the objective of the test is to detect and/or size discontinuities, the parameters which have to be measured such as length, depth and position are defined and the maximum acceptable deviations of reported defect positions and sizes are specified.

If applicable, the acceptance and rejection criteria for detection are defined.

• description of the NDT equipment (including software used);

• NDT techniques;

• calibration requirements;

• list of essential parameters;

• range of variation acceptable for these parameters;

• NDT personnel requirements;

• any safety precaution to be taken;

• instrument settings;

• scanning method and sensitivity;

• decision process to interpret the indications;

• reporting level and acceptance standard;

• documentation requirements.