Ultrasonic Techniques

Ultrasonic testing is a very mature highly, tailorable technology. In the hands of ALS expert staff, It has excellent application for determining:

• Component thickness.
• Finding and sizing cracking, even in complicated component geometries.
• Assessing the extent of corrosion and corrosion loss.
• Finding welding, casting and manufacturing defects and assessing compliance of welds with applicable standards.

ALS provides a range of ultrasonic techniques that cater for the most accurate finding and sizing of internal features through to more rapid scanning approaches that provide high productivity assessment outcomes.

ALS experienced staff provide:

Manual Ultrasonic Testing

Using high quality hand held probes and ultrasonic units, ALS technicians can assess many different material types for the presence of defects.

Advantages – Accurately detects and sizes many sub-surface features and provides accurate Remaining Wall Thickness assessment.

Applications – Most components and structures for both compliance to standards (e.g. AS, ISO, ASME and other international standards) and for condition assessment.

Semi-Automated Ultrasonic Testing

Using scanning frames and machines, semi-automated ultrasonic equipment can rapidly scan large surface areas and give a high quality indication of internal defects, i.e. cracking, corrosion and remaining wall thickness.

Advantages – Accurately detects and sizes many sub-surface features. Capable of working in many different material types.

Applications – Components where continuous scanning of surfaces provides integrity knowledge and assessment, defect detection and critical sizing.

Phased Array and Ultrasonic Testing (PAUT) – By utilising an array of ultrasonic transducers, a tailored ultrasonic wave form can be created that is designed for inspecting particular geometries and finding particular flaws / features of concern. The equipment used in this Advanced NDT technique also records a permanent record of inspection.

Advantages – Accurately detects and sizes many sub-surface features. Capable of working in many different material types.

Applications – Most component and structures where specialised flaw inspection is required. ALS optimised applications for many critical components, including:

• Tank Construction Welds
• Bolt Inspection for internal corrosion and breakage
• Shafting cracking in complex shaft geometry
• Non Intrusive Inspection (NII) of upstream oil and gas equipment.
• Complex geometry scanning, such as Nozzle to Shell welds
• Shafts and pins for detection of cracking
• Turbine components for detection of critical cracking and corrosion

Time of Flight Diffraction (TOFD) – This Advanced NDT technique can be used in combination with PAUT (PAUT/TOFD), and provides high accuracy sizing of flaws.

Advantages – Accurately detects and sizes many sub-surface features, and is not affected by defect orientation.

Applications – Typically utilised for weld quality assessment either on its own or in combination with PAUT. Well suited to in-service process related and defect detection.

Internal Rotating Inspection Systems (IRIS)

Mainly for non-magnetic tubing (but can be used on other materials), IRIS utilises a rotating ultrasound signal to inspect tubing for defects. The technique provides inspection capability where other methods fail.

Advantages – Accurately find defects and wall thickness loss in heat exchanger and cooler tubing.

Applications – Heat exchangers, Fin Fan Coolers, boiler tubes

Long Range Ultrasonic Testing (LRUT or Guided Wave (GWT))

This Advanced NDT technique works by creating an ultrasonic wave form that travels both longitudinally and circumferentially, allowing long lengths of piping to be scanned.

Advantages – Excellent screening tool in long components such as pipework for evidence of localised thickness loss (e.g. external and internal corrosion pits).

Applications – Particularly for pipework including examining for Corrosion Under Insulation (CUI). Also inspection of long steel structural elements such as steel piles and structural columns as well as Under Pipe supports and buried piping. Suitable for assessing piping going through bund walls and other concrete structures.

Short Range Ultrasonic Testing (SRGW or Short Range Guided Wave)

This Advanced NDT technique is focussed on inspecting short distances of difficult to inspect component geometries.

Advantages – Provides scanning in frequently inaccessible locations, for example buried piping, pipe supports looking for evidence of corrosion. Not as affected by coatings and painted surfaces as some other methods.

Applications – Air Ground Interfaces (AGI) and piping just below ground exposed to external corrosion, Pipe Supports, Tank Floor annular ring scanning from external annular protrusion.

EMAT - Electromagnetic Acoustic Transducers

This Advanced NDT technique that uses an electric coil and strong magnets to create an ultrasonic signal in the material under test.

Advantages - Scanning can be performed by introducing ultrasonic signals in a circumferential or longitudinal direction. Distances of up to 10.0m in longitudinal mode can be covered in both directions from the scanner. Scans can be performed in ferromagnetic material and at elevated temperature. This advantage makes this technique good for on-line inspection, avoiding where possible unnecessary shutdown.

Applications - Scanning of piping at touch point locations to detect corrosion under pipe supports (CUPS). Scanning of vessels, tank floors, and piping can also be performed. Scanning of air to ground (AGI) piping is also possible.