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Ultrasonic Testing

High-frequency sound waves deployed for volumetric flaw detection, weld inspection, thickness measurement, and material characterisation — one of the most versatile and widely applied NDT methods in industrial inspection.

What Is Ultrasonic Testing?


Ultrasonic Testing (UT) uses high-frequency sound waves — typically in the range of 0.5 to 20 MHz — introduced into a component via a transducer coupled to the inspection surface. The sound wave travels through the material and reflects from internal boundaries, discontinuities, or the back-wall surface. The time of flight and amplitude of the returning signal are used to detect, locate, and size internal flaws and measure material thickness.

The method requires skilled application: transducer selection, calibration, scan plan development, and signal interpretation all directly affect the reliability of inspection results. Our UT technicians are certified to PCN (ISO 9712) or ASNT Level 2 minimum, with Level 3 supervision available for complex or code-critical applications.

Where We Apply UT


  • Weld inspection — butt welds, fillet welds, nozzle welds, and repair welds in pressure vessels, piping, structural steelwork, and marine structures
  • Pressure vessel shell and head inspection — detection of laminations, inclusions, and fabrication defects
  • Pipe and piping circuit inspection — longitudinal and circumferential seam welds; in service corrosion and erosion assessment
  • Structural steelwork — flange, beam, and connection inspection during fabrication and in service assessment
  • In-service crack detection and sizing in rotating equipment, support structures, and pressure-containing components

Applicable Codes and Standards


Our UT inspections are performed to applicable national and international codes, including:

  • ASME Section V — Boiler and Pressure Vessel Code, Article 4 (Ultrasonic Examination Methods)
  • ASME Section VIII — Pressure vessel construction and examination requirements
  • AWS D1.1 — Structural Welding Code (Steel)
  • API 570 — Piping Inspection Code
  • API 510 — Pressure Vessel Inspection Code
  • EN ISO 11666 — Non-destructive testing of welds — Ultrasonic testing — Acceptance levels
  • ASTM A388 — Standard Practice for Ultrasonic Examination of Steel Forgings