Non-destructive testing

Conventional NDT

Conventional NDT has historically been the initial point for evaluating and verifying an asset’s compliance for safe operation. From ‘fabrication’ to ‘in-service’ examinations, conventional NDT can be used to detect threat mechanisms as a cost-effective method for identifying compliance to relevant codes and underlying ‘in-service’ condition of the component.

Implementing the correct frequency of inspections allows the early identification of potential issues, enabling monitoring or repair strategies to be implemented prior to any unplanned failure.

Visual Inspection

Visual Inspection (VT) is the most commonly used form of NDT. Visual inspections (with or without optical aids) provide the first point of assessment for all components requiring integrity management. From this point, appropriate inspection techniques are employed for further investigations of the component.

Dye Penetrant Inspection

Dye Penetrant Inspection (DPI) is a widely applied NDT technique for non-porous materials, to detect cracks, porosity, seams and laps at point of fabrication, or fatigue cracks while in-service.

Magnetic Particle Inspection

Magnetic Particle Inspection (MPI) is one of the most commonly used methods of NDT and is carried out to test for discontinuities such as cracks, porosity, seams and laps at point of fabrication, or fatigue cracks while in-service.

Eddy Current Inspection

Eddy Current testing (ECI) examinations are carried out to test for surface breaking fatigue cracks under non-conductive, or conductive coatings using an electromagnetic field. This technique allows protective coatings to remain intact, keeping corrosion protection in place. MPI is used to confirm the detection of fatigue cracks found by ECI.

Ultrasonic Wall Thickness Testing

Ultrasonic Wall Thickness Testing (UTWT) can be used for a range of examinations from confirming the thickness of a material through to flaw detections such as laminations, inclusions, and stringers at point of fabrication. UTWT can also be used for bond integrity, back wall corrosion detection and monitoring during in-service.

Ultrasonic Weld Inspection

Manual Ultrasonic Weld Inspection (MUT) can be used to inspect welds using a range of angles to interrogate full weld volume for embedded planar, and volumetric flaws. Detection of flaws such as porosity, slag, lack of inter-run fusion, lack of side wall fusion and cracks can be detected at the point of fabrication, or fatigue cracks and corrosion while in-service.

Specialist NDT

Complex inspection challenges require specialist solutions

NDT has advanced to address emerging concerns on ‘ageing assets’ where the requirement for higher Probability of Detection (PoD) for any given flaw is required, while minimising false calls and where more meaningful data is required to establish the ageing ‘in-service’ condition of components. This data can feed into engineering predictive modelling, reducing unplanned downtime and costs.

Ethos Inspection Solutions provide an extensive range of specialist inspection capabilities for applications for the detection of complex threat mechanisms arising during the assets ‘in-service’ lifecycle.

Corrosion Mapping

Corrosion Mapping (UTCM) is a widely used technique that uses zero-degree ultrasonics collected manually or fully automated (dual axis scanners or robotic crawlers) for the in-service detection and characterisation of degradation mechanisms in pressure systems. A map of the area is generated with different colour scales relating to varying thicknesses. Data can be presented in different formats such as composite images of the component, 3D overlay or CSV files for statistical analysis.

Phased Array

Phased Array Ultrasonics (PAUT) is a powerful technique that offers flexibility in the range and type of data collection the technique can perform. From Corrosion Mapping (as mentioned above) to weld inspection including complex geometries. PAUT allows for a more reliable inspection than manual ultrasonics, storing all hard copy data. All raw A scans are recorded for offline analysis allowing comparisons to previous inspections year on year.

$Time of Flight Diffraction$

Time of Flight Diffraction

Ultrasonic Time-of-Flight Diffraction (TOFD) technique is a sensitive and highly accurate method for measuring the through wall height of embedded flaws within welds. The through wall accuracy of the technique makes it a powerful tool for the monitoring of vertical planar flaws and threats such as preferential weld root corrosion (PWRC). TOFD produces and saves real time images, including raw A-scans for offline analysis. TOFD A scans cannot be used for flaw characterisation and individual angles are used with compression waves to cover the weld volume. Different angles are required to cover full volume of heavy walled material and it is common for TOFD and PA to be deployed simultaneously.

Guided Wave Inspections

Ultrasonic Guided Waves (GW) have generated growing interest over the past decade as the range of applications for which guided waves are proving useful is rapidly growing.

The nature of guided waves, which can propagate long distances, yields tremendous potential for time and cost savings during the inspection of a wide variety of structures from railway tracks to pipelines to aircraft skins. Guided Waves can achieve much greater inspection ranges than traditional ultrasonic testing methods because they utilise the structure itself as a waveguide by exploiting resonances between the boundaries of the component (i.e. the surfaces of a plate or the OD and ID of a pipe).

Alternating Current Field Measurement

Alternating Current Field Measurement (ACFM) technique is a non-contact electromagnetic technique capable of both detecting and sizing (length and depth) planar flaws in metals under coatings (removing the need to expose the test surface). The basis of the technique is that an alternating current flows in a thin skin near the surface of any conductor. By introducing a remote uniform current into an area of the component under test, when there are no defects present, the electrical current will be undisturbed. If a crack is present the current flows around the ends and down the faces of the crack and phase angle of the display signal changes identifying the presence of fatigue cracks.