Weld inspection in pipelines and pressure vessels
Time of Flight Diffraction (TOFD)
Accurate Detection of Defects in Ferromagnetic Materials
INTRODUCTION
Time-of-Flight Diffraction (ToFD) is an advanced ultrasonic technique used to detect and size defects in welds and components with exceptional precision.
Unlike conventional ultrasonic testing, ToFD relies on the diffraction of sound waves from flaw tips rather than reflection from surfaces.
This provides highly accurate and repeatable results for detecting cracks, lack of fusion, and other discontinuities, especially in welds and pressure vessels.
How Time of Flight Diffraction Works? |
Time-of-Flight Diffraction (ToFD) operates by transmitting ultrasonic sound waves into a material using a pair of angled probes one transmitter and one receiver positioned on opposite sides of a weld or component. When these waves encounter a defect such as a crack or flaw, the sound diffracts from the edges or tips of the discontinuity, creating distinct signals that are captured by the receiver. By accurately measuring the time it takes for these diffracted signals to travel, the system determines the size, location, and depth of each flaw with exceptional precision. The data is displayed as a B-scan image, providing a permanent visual record of the inspection that allows for easy analysis and reliable defect sizing.If any discontinuity or crack is present, it creates a leakage field that attracts the magnetic particles, forming a visible indication under white light or ultraviolet light (for fluorescent MPI). This simple yet powerful method helps identify even the smallest imperfections before they lead to costly failures or safety risks.
Applications of tofd
ToFD is widely used across industries where accuracy and traceability are critical.
It is ideal for weld inspection, corrosion monitoring, and component evaluation, ensuring both compliance and safety in high-stress environments.
Typical Applications Include:
Detection of planar flaws and lack of fusion
Inspection of heat-affected zones
High-integrity fabrication and in-service evaluation
Advantages of tofd
Time-of-Flight Diffraction (ToFD) offers several key advantages that make it a superior choice for volumetric inspections.
It delivers accurate defect sizing, fast data acquisition, and comprehensive coverage in a single scan.
The method provides permanent digital records, enhancing traceability and reducing the need for reinspection.
Types of tofd Methods We Use
At Lateral Wave Pty Ltd, we utilise different ToFD configurations to suit varying component geometries and inspection needs.
Why Choose Lateral Wave Pty Ltd for tofd?
Our ToFD technicians are certified to Australian and international NDT standards, ensuring top-quality inspections.
We use state-of-the-art ultrasonic scanners and data analysis software for reliable, repeatable results.
Our inspection reports include clear visual data and defect sizing charts for easy interpretation.
We prioritise efficiency and minimal downtime, delivering accurate results even under tight project schedules.
We offer 24/7 inspection availability across Australia, ensuring timely response and support for critical shutdowns, maintenance, and construction projects.
Accurate, traceable, and reliable defect sizing with ToFD inspections
Request an Inspection
Ensure the integrity of your welds and structures with Time-of-Flight Diffraction (ToFD) at Lateral Wave Pty Ltd.
Contact our certified inspection team to schedule your evaluation or request a detailed quote.
Call us at (+61) 0420 303 358 or email info@lateralwave.com.au to schedule your inspection or request a detailed quote.
