 Table of Contents ECNDT '98 Session: Ultrasonic | Qualification and Validation of New SAPHIR - UT - TechnologyR. Heumüller, G. Guse, B. RückeltSiemens/KWU, Dept. NW-P, Erlangen phone +49 9131 18 3650 Corresponding Author Contact: Roland Heumueller Email: Roland.Heumueller@erl11.siemens.de |
| TABLE OF CONTENTS |
This contribution states, that the proceeding according the ENIQ-Methodology demands systematic and detailed considerations and proofs with valuable perceptions and benefits by resulting in higher sureness for inspection and performance.
The example of the recent SAPHIR-validation may illustrate that:
The new UT equipment SAPHIR combines the features of the former Siemens-ALOK-System and the former Siemens-Phased Array System. Before its use in the field service it has been characterised and validated as an UT equipment fit for its purpose.
This internal validation was done in different steps:
Starting from the stipulation of all requirements on an inspection equipment in the detailed specification a validation script (with demand, method and tool and tolerances for measurement) was created. Using that systematically all testable modules of hardware and software of the system are checked and accepted at the level of single modules. The same was done after integration of modules to instruments/programmes and at least at the level of the complete UT equipment system.
The general acceptance for inspection of thick-walled pressure vessel according to the German code was reached very efficiently basing on the above preparatory work as qualification of a "General procedure for RPV shell weld inspection in accordance with KTA 3201.4".
NDT Qualification is the systematic assessment of an NDT System to ensure it is capable of achieving the required performance under real inspection conditions. The NDT System includes the subsystems equipment, procedure and personnel [1]. Therefor it makes logically and economically sense, to characterise and validate a new UT equipment like SAPHIR generally ahead of a specific NDT procedure qualification.
The value of a certain proceeding in the frame of industrial use is measured by the cost-to-benefit relation. The single elements and ideas of the ENIQ - Methodology [2], especially the concept of Technical Justification [3], are very important for that relation, especially in contrast to a more black-box orientated proceeding like in accordance with ASME, Sec. XI, App. 8. where an expensive yes/no decision is yielded, which seems to be highly depending on just a single operator conducting the inspection and promoting not any principal understanding of the NDT System.
Fig 1: The sketch of the reactor pressure vessel inspection system with SAPHIR may give an impression of the complexity of such a system and its procedure qualification |
The sketch of the reactor pressure vessel inspection system with SAPHIR in fig. 2 may give an idea of the complexity of such a system.
The entire complex system is built of simpler modules e.g. UT-instrument (hardware and firmware), data acquisition and evaluation software etc. which have to be qualified each in a single stand-alone validation step. Developing, manufacturing, and acceptance were done in accordance with DIN ISO 45000:]
These steps are not directly related to any qualification methodology, but as a penetrating quality and reliability concept it enters into the effort and direction of the Technical Justification.
The direct steps of the validation have been:
Fig 2: Modules of SAPHIR - inspection system as modules of the validation |
Thereby a clear and open construction of ideas and expectations is described:
| 1.3.2 | check point: LINEARITY CHECK | test tools: | test procedure: | expected value / tolerances & statements after execution of test |
| 1.3.2.1 | Linearity of the Logarithmic Amplifier | Electronic calibration signal device: B 501/02, Gain setting according sheet SAP_5-21 | For every set of parameter one "TAKT" is programmed:
1, 2, 3, 4 MHz Coarse gain: 0, 10, 20, 30, 40 dB -10 dB steps for attenuation by Calibration Signal Device : Acceptable result: in range 20-60 dB deviation not bigger than 1.5 dB in other ranges: deviation not bigger than 2 dB | The measured values are in the acceptable range: see protocol # 1.3.2.1. |
| 1.3.2.2. | Distribution of Measured Amplitudes of a Static Signal (numeric) | Distribution of measured values acceptable according DIN 25450 (09/90) and DIN 25435 T 1. | Statement: Distribution of measured values fulfils the requirements according DIN 25450 (09/90) and DIN 25435 T 1. |
Fig 4: Geometry of the used Mock-Up (view from inside to outside)
Fig 5: Defect situation at the used Mock-Up (Sketch of Flaws) |
In the course of the performed general validation [7] of the SAPHIR system neither the inspection technique (in accordance with KTA 3201.4) nor the manipulation technique were new and needed a qualification. Therefor the validation trials focussed on the functional proof of the phased array technique, the co-operation of the subsystems, the handling and adequacy of the QA-measures, and the handling and evaluation of inspection results. The full qualification process for routine operation in the region of the German regulators was therefor completed during several days.
This is rather effective in economical sense and flexible in terms of adaptation to other qualification tasks. Qualification for those specific inspection tasks can focus on the reliability and efficiency of the used techniques and rely on the general qualification by arguing in the Technical Justification.
Blind Trials of personnel are not included in this qualification:
For the inspection personnel with SAPHIR a specific training and examination is stipulated in the procedure as supposition for the Operator Authorisation acc. EN 473 [8] and for the inspection of cladded ferritic materials with standard NDT-techniques there are no specific knowledge needed and no decisions to be taken beyond the routine ones. The personnel have to proof their ability to work with the equipment and the general procedure, but - in contrast to specific jobs like inspection of austenitic welds - this is not seen as a matter for procedure related blind trials.
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