PAUT

In PAUT, many small ultrasonic elements are excited individually with controlled delays so that the sound beam is steered and focused electronically. Several angles can be scanned from a single probe position, and the result is presented as a sectorial image.

The aim is an examination that is faster, broader in coverage and image-based compared with conventional UT. That the result can be recorded is the main reason it is used as an alternative to radiography.

• Pressure equipment and pipeline weld seams
• Thick-walled components
• Welds with complex geometry (nozzles, branch connections)
• Corrosion mapping
• Storage tank and ship structure welds

NDT has no interval of its own; how often it is applied follows the inspection programme it serves. In manufacturing the governing factor is the coverage required by the product standard and the specification (e.g. a given percentage of welds); in operation it is the asset integrity or risk-based inspection programme.

• Internal cracks and planar defects
• Lack of penetration and lack of fusion
• Slag and porosity
• Sizing of defect depth, height and length
• Wall thickness and corrosion map

• ISO/IEC 17020
• ISO 13588
• ISO 19285
• ISO 18563 series
• EN ISO 17640
• ISO 9712

• Phased array ultrasonic instrument
• Phased array probes and wedge sets
• Encoder and scanning rig
• Reference calibration blocks
• Couplant
• Data recording and analysis software

1. 1Selection of Method and TechniqueThe type and location of the discontinuity sought and the material properties are assessed to select a suitable method and technique; a written procedure is prepared.
2. 2Verification of Personnel and EquipmentThe level and industrial-sector qualification of the operator under EN ISO 9712 and the calibration records of the equipment are checked.
3. 3Surface PreparationThe inspection surface is prepared as the method requires; coating, rust and contamination directly affect the sensitivity of the method.
4. 4Calibration and Sensitivity VerificationA reference block or control specimen is used to demonstrate that the system can detect the discontinuity sought.
5. 5Performing the InspectionScanning is carried out according to the procedure; indications are recorded and located.
6. 6AssessmentIndications are evaluated against the applicable acceptance standard to determine whether they are defects; they are sized.
7. 7ReportingMethod, technique, equipment, calibration, findings and acceptance criteria are reported together.

Defects are located and sized on the sectorial scan image. The acceptance criterion is determined according to a standard such as ISO 19285 and the applied quality level; defect height can also be used in fracture-mechanics-based assessment.

• The inspection body and the personnel's EN ISO 9712 level and sector
• Method and technique applied and the written procedure number
• Part and weld examined, with a location sketch
• Equipment, consumables and calibration records
• Surface condition and inspection conditions
• Indications recorded, with their location and size
• Acceptance standard applied and the result of the evaluation
• Accept / reject decision

Non-destructive testing is carried out as an accredited inspection activity under ISO/IEC 17020. The second decisive factor in NDT is personnel qualification: the operator must be certified under EN ISO 9712 for the method, level and industrial sector concerned. An examination performed with a method outside the scope of that certificate is not valid. EUROLAB holds internationally recognised accreditation under ISO/IEC 17020, granted by accreditation bodies that are signatories to the ILAC mutual recognition arrangement.

• VT Visual
• PT Penetrant
• MT Magnetic Particle
• UT Ultrasonic
• RT Radiographic
• ET Eddy Current
• TOFD
• Leak Testing