ToFD and Non-Destructive Testing
High Precision Weld Inspection with TOFD
Welding defects can compromise the stability and integrity of a welded structure. When you need confidence in testing of welds, Time of Flight Diffraction (TOFD), a high performance non-destructive testing (NDT) technique offers you accurate detection of cracks, slag and lack of fusion.
Since the early 1990s, TOFD has been utilized in several international round robin exercises, where it was validated against the more traditional radiographic and pulse echo manual and automated weld testing methods . The results of these tests demonstrate the superior performance of TOFD. We at TÜV Rheinland have many years of experience with weld testing by means of TOFD. Our inspection team is also one of the best-resourced in the world. Our involvement in equipment development, inspection solutions and accredited TOFD training courses demonstrate our commitment in the use of this technique.
We accompany you throughout your testing project and offer you individual solutions. Our capabilities include but are not limited to consultancy services prior to inspection, weld testing using TOFD technique, data processing with our in-house developed software, assistance in interpreting of inspections´ finding. We believe that using our TOFD inspection service will lead to major time savings during the life cycle of new build and replacement projects. It is an excellent and widely accepted pre-service and in-service inspection tool that is recognized internationally, with defined codes, standards and acceptance criteria available for its use.
TÜV Rheinland Sonovation is part of the TÜV Rheinland Group specialized in providing a complete range of advanced non-destructive testing (NDT) services. In addition to operating a competence center for advanced NDT based in the Netherlands, it maintains branches in the United Kingdom, Belgium, Germany and Saudi Arabia. Acknowledged as leaders in the field, TÜV Rheinland Sonovation invests heavily in R&D and operates an accredited training school for advanced NDT as well as offering its expert services globally.
Benefits of Our TOFD Inspection Services at a Glance
Our TOFD inspection services offer you:
- Higher probability of failure detection compared to conventional procedures such as radiographic testing (RT) and ultrasonic testing (UT) .
- Reduced costs, as TOFD inspections can take place on-site alongside production work during the day shift.
- No logistical difficulty as in the case of radiographic testing.
- Quick results, as inspection time is not as highly affected by material thickness as it is in the case of radiographic testing.
- Material examinations and inspections are possible even to temperatures exceeding 400°C.
- Accurate inspection data presented in an easily understood format and stored in digital form for future reference provided by our ScanPlan® software.
- Reduced risk of company liability thanks to documented safety standards.
- Certified inspectors in accordance with the TOFD certification program based on EN473.
- The convenience of an exclusive one-stop shop solution.
Our TOFD Inspection Approach
We at TÜV Rheinland are dedicated to finding the optimal non-destructive testing method that will perfectly meet your needs. Whether or not the TOFD inspection technique is suitable for you depends on many different factors. You can rely on our experience to ascertain your requirements and you can be confident of our expertise in TOFD, a technique we have utilized in testing for the past quarter of a century.
The TOFD inspection approach begins with two ultrasonic probes, which are positioned on either side of the weld, one acting as a transmitter and the other as a receiver. The longitudinal sound beam will then encounter obstacles along its path, which cause signals to be reflected and diffracted. When the probes are moved in a parallel motion along the weld, the resultant waveforms are digitized, stored on hard disk and displayed on the video-screen as a grey scale image. The image built up is in effect a through sectional view of the examined weld and can be used for accurate measurement and detection of indications. All data collected with the TOFD system is stored for future reference.
If further analysis is required on inspection data, our in-house developed custom analysis software ScanPlan®, is available. Alternatively, we can provide you with read-only data in a format compatible with the most commonly used inspection and maintenance data management systems.
TOFD Application Range
Our TOFD service can be used for:
- Construction weld inspections.
- Intermediate inspections to examine partially filled welds at the preheat temperature.
- In service inspection at ambient or high temperatures.
- Examination of steam drums used in power generation.
- Root corrosion detection in piping vessels.
- High temperature weld inspection of up to nearly 500°C.
- Inter granular stress corrosion cracking in welds.
- Pre-service inspection of piping welds, duplex pipeline welds and spherical storage tanks.
- Nozzle inspection.
More Information on Our ScanPlan® Software
With TÜV Rheinland´s ScanPlan® you get a software, that:
- Is based upon more than twenty years’ exprerience of applying ToFD on pressure equipment.
- Helps the professional preparation of inspections and minimises the preparation time required.
- Supports the creation of inspection test plans.
- Demonstrates the efficiency of the technique.
- Has an inspection-friendly user interface.
- Offers seven different weld configurations to choose from.
- Offers scan parameters in accordance with international codes and standards.
- Allows instant selection of base geometry and thickness details.
- Optimizes the ToFD solution chosen by the operator.
- Provides output as hard copy or digital document.
- Records all inspection data.