Non-destructive testing and inspection

Corrosion is usually accompanied by a reduction of metal loss and integrity of the material, but is not always visible to the naked eye. To determin the cause of corrosion ( and leaks) metallurgical examination (including X -ray and microscopic examination + SEM-EDX ) is most effective and reliable, but because of the destructive nature of it (it usually requires the removal removal of a pipe section for instance) not always possible. In that case, the CCTA has a wide range of non-destructive techniques available that can be used to form a hypothesis about the situation and the cause of the problem and to define an advice. Besides the standard NDT techniques ( Magnetic, Penetrant , Ultrasonic and Radiographic examination ), the Corrosion Control Technology Alliance offers a number of advanced techniques to detect and quantify the corrosion mechanism.

Guided Wave is a low frequency ultrasonic technique which is specially developed for rapid mapping of both internal and external corrosion in pipes. The ultrasonic energy is conducted in a longitudinal direction and reflects on irregularities such as corrosion..

Time of Flight Diffraction(TOFD)is an ultrasonic technique which is applied for measuring the residual wall thickness of a weld. For example in case of corrosion and or erosion of the welds. The measured accuracy of the residual wall thickness is better than 0.5 mm.

Phased Array(PA)is an ultrasonic technique for measuring surfaces of 4 – 7 cm. It displays wall thickness measurements at a much greater speed and reliability than performed by conventional ultrasonic wall thickness measurements.

Tank survey by applying an acoustic emission technique which provides information about the condition of a tank bottom by measuring active corrosion whilst the tank remains fully operational.

LSI (Large Structure Inspection) is a system using ultrasonic technique, developed for fast mapping (1m² in 4 minutes) of localized corrosion on carbon steel tanks and pipelines. Applying LSI large areas can be scanned at the same time, with adjustable resolution.

Other services offered

- Sampling for chemical and microbiological analysis
- Potential difference measurements and advice for cathodic protection
- PCMS plant condition management software and RBI
- Inspection and NDT with minimal disruption to production
- Assessment according to norms and standards
- Calculations on equipment life and piping on the basis of inspection and monitoring
- Fitness for Service; corrosion and material advice to determine which conditions may damage your systems.
- Corrosion monitoring

Contact: Frans van der Kolk
T. +31 (0)10 234 1082
F. +31 (0)10 234 11726