In pressure equipment, pipelines and thick-section welds, it is not enough to know whether a discontinuity exists; its position and size must also be known. Alongside conventional ultrasonic testing (UT), Phased Array Ultrasonic Testing (PAUT) and TOFD (Time of Flight Diffraction) meet this need with recorded, image-based data.
PAUT uses a probe made up of many elements; by exciting these elements with time delays, the instrument steers the sound beam to different angles and focuses it at a given depth. A range of angles is thus scanned from a single probe position and the weld cross-section is evaluated as an S-scan image. TOFD, in turn, measures the arrival time of signals diffracted from the tips of a flaw; because sizing relies on time rather than signal amplitude, the height of planar flaws is determined reliably. Application practice is defined in standards such as TS EN ISO 13588 for PAUT and ASTM E2373 and ASME BPVC Section V, Article 4 for TOFD, while acceptance levels are defined in standards such as TS EN ISO 19285 for PAUT and TS EN ISO 15626 for TOFD.
Both methods are ultrasonic and involve no ionising radiation, so the work area does not need to be cleared during the inspection. Data recorded with encoder positioning is archived and can be re-evaluated when needed. TÜV AUSTRIA SILA KALİTE is an inspection body accredited by TÜRKAK under TS EN ISO/IEC 17020. We carry out these inspections within our Advanced Non-Destructive Testing service, using an equipment fleet that also includes digital radiography, corrosion mapping and crawler systems. Our Phased Array equipment is verified to the TS EN ISO 18563 series, and inspections are performed and evaluated by our expert personnel certified to at least Level 2 under TS EN ISO 9712.
Related services and training
- Phased Array (Phased Array UT)Three-dimensional inspection and imaged reporting of welded or unwelded structures; the ability to sweep, focus and image in real time across all angles.
- ToFD (Time of Flight Diffraction)An ultrasonic method that tests weld seams and critical areas with high accuracy, involves no radiation hazard and provides reliable flaw sizing.
- Ultrasonic TestingA non-destructive testing method that determines the location, size and type of discontinuities by making use of the reflections of high-frequency sound waves within the material.
- Ultrasonic Testing (UT) Level 2 — EN ISO 9712 PreparationLevel 2 competency training for weld and volumetric examination using angle and normal probe techniques.