Ultrasonic examination

Figure 6 shows the histogram of localized AE events vs axial position for the same time period as in fig.5. The location of the AE source corresponds, within source location errors (< 10-15 cm), to one of the welds under surveillance. The weld was known by ultrasonic examination to be affected by internal discontinuities. However, the position of the source could also correspond to one of the hangers. The steps observed in EA event accumulation have taken place during steady load operation, which normally corresponds to very low background noise conditions. This type of event, however, has not been observed afterwards. 

Insurance in pressure boundary integrity of NPP unit is strongly influenced by technical capabilities and efficiency of metal examination system. Ordinary ultrasonic examination tools and procedures have limitations in flaw sizing and positioning. The problems arise for welds and repair zones of welds made by filler materials of austenitic type. 

Information supplied by flaw visualization systems has decisive influence on fracture assessment of the defect. Results of expert ultrasonic examination show that in order to take advantage of AUGUR4.2 potentialities in full measure advanced methods of defect assessment should be applied using computer modelling, in-site data of material mechanical properties and load monitoring [4]. 

This paper describes the development of a novel system for improving the quality of information provided by manual ultrasonic examination of welds, while retaining the flexibility of the human operator to apply the techniques to components of a wide range of geometries and dimensions. The system, known as CamuS (Computer Aided Manual UltraSonics) provides assistance to the manual operator in two separate areas ... 

The first stage in any inspection is to generate a proeedure which is specific to the component being examined in many instances, such a procedure will be based on a standard such as CEN J5I/-EN1714 Non-Destructive Testing of Welds - Ultrasonic Examination of Welded Joints . CamuS incorporates a tool ProcGen to provide assistance with this task. 

J. ASME XI Boiler and Pressure Vessel code. Appendix III "Ultrasonic examination of piping systems ... 

Robot System for Ultrasonic Examination of Complex Geometries. 

The principal equipment for the ultrasonic examination is the P-scan system, PS-4, which is a computerised ultrasonic system, developed by FORCE Institute, for automatic, mechanical and manual ultrasonic examination of welds and materials. The system has documentation and storage facilities for all data related to each inspection operation, and includes visualisation of the inspection results in the form of images of the material volume examined. 

The PS-4 ultrasonic examination system provides many new features, which allows the operator to perform several inspections simultaneously. Both pulse-echo and time-of-flight-diffraction technique can be applied together with storage of digital A-scan data at the same time. 

EN 230 Ultrasonic examination - Caracterization and verification of equipment- Part 1 Flaw detectors ... 

Ultrasonic Examination Ultrasonic examination of welds shall be in accordance with Art. 5, Sec. V of the ASME Code, except that the modifications stated in Far. 336.4.6 of the code shall be substituted forT-535.1(tZ)(2). 

Rules for the welded fabrication of pressure vessels cover welding processes, manufacturer s record keeping on welding procedures, welder qualification, cleaning, fit-up alignment tolerances, and repair of weld defects. Procedures for postweld heat treatment are detailed. Checking the procedures and welders and radiographic and ultrasonic examination of welded joints are covered. 

Ultrasonic Examination. Main load carrying components of the equipment shall be ultrasonically examined in accordance with applicable ASTM standards. The extent of examination, method of examination, and basis for acceptance shall be agreed upon by the manufacturer and purchaser. 

B 977 525 354 2.44 14 Blistering was detected with ultrasonic examination in catalytic reformer piping. Metallography indicated surface decarburization and blistering at non-metallic inclusions, with intergranular cracks growing from the blisters. Cr content was 1.10 percent. 

Other Examination. All circumferential butt and miter groove welds shall be examined by 100% radiography in accordance with para. IP-10.5.2. Alternatively, when specified by the engineering design, ultrasonic examination 100% shall be performed in accordance with para. IP-10.5.5. Socket welds and branch connection welds that are not radiographed shall be examined by magnetic particle or liquid penetrant methods in accordance with para. IP-10.5.4 or IP-10.5.3. 

Ultrasonic examination shall be used when specified by the engineering design and shall be performed based on the following requirements ... 

Closure Welds. The final weld connecting piping systems or components that have been successfully tested in accordance with para. IP-10.6 need not be leak tested, provided the weld is examined in-process in accordance with para. IP-10.5.1(c)(8) and passes with 100% radiographic examination in accordance with para. IP-10.5.2 or 100% ultrasonic examination in accordance with para. IP-10.5.5. 

An Ej factor of 1.00 may be applied only if all welds, including welds in the base material, have passed 100% radiographic examination. Substitution of ultrasonic examination for radiography is not permitted for the purpose of obtaining an ) of 1.00. 

The sensitivity of the ultrasonic examination of the welds shall be calibrated in accordance with paragraph 9.15 of API 5L and the following provisions ... 

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