Thu, 29 October, 2020
Non-destructive testing (NDT), also known as non-destructive examination (NDE), non-destructive inspection (NDI) and non-destructive evaluation (NDE), is a common term used for techniques used in the science and technology industry to observe and measure welding defects or characteristic differences in a structure, component or material without damaging the original structure.
TWI services in Southeast Asia provides non-destructive testing services to a wide range of industry sectors, from oil and gas to power, ensuring maximum safety and reliability with minimum disruptions to the operations of the equipment and plant assets.
Our team of skillful engineering experts have carried out numerous projects in this field and we are confident in offering the best inspection services to our clients.
Application and Methods
Depending on the conditions and situations, various techniques of NDT can be utilised for inspection during or after the production process, while in service or following repair. NDT services are a major component of our other key service which is failure investigation that provides key test data for procedures such as fitness for service (FFS) and risk based inspection (RBI).
The current NDT methods that we have expertise in include:
Electromagnetic Testing (ET)
As a general test category, the electromagnetic testing method uses the principal of electromagnetism as the basis for conducting examinations. This test category includes three different techniques of eddy current testing, alternating current field measurement (ACFM) and remote field testing.
Magnetic Flux Leakage (MFL)
MFL or transverse field inspection technology is an NDT method commonly used to detect corrosion and pitting in steel structures of pipelines and storage tanks by utilising powerful magnets to create magnetic fields in steel structures. Where there is a defect, there will be leakage of magnetic field.
Liquid Penetrant Testing (PT)
One of the most common NDT techniques which uses low viscosity fluids on the surface of structures. Where there is a defect, the penetrant liquid seeps upwards and creates a visible indication of the flaw.
Magnetic Particle Testing (MT)
Another common NDT technique used for detecting defects and discontinuities on the surface and subsurface using the concept of magnetic field.
Radiographic Testing (RT)
A subsurface defect detection technique using X-rays or gamma rays. To interpret the results, various methods, such as film radiography, computed radiography, computed tomography or digital radiography, can be used.
Thermal/Infrared Testing (IRT)
In this method of non-destructive testing the temperature variances of a structure are measured as heat flows through, from, or to that structure. Infrared testing is also commonly known as IR testing, thermal testing, thermal imaging, and IR thermometry.
Conventional Ultrasonic Testing (UT)
As one of the most fundamental NDT techniques to other advanced methods of NDT, ultrasonic testing utilises sound waves to detect defects in components and structures. It is also used to measure a material's thickness, such as measuring the wall thickness of a pipe.
Using the concept of ultrasonic testing, various other techniques have been designed to identify defects, discontinuity and thickness of material. These methods include, pulse echo inspection, through transmission testing, time of flight diffraction (ToFD), immersion testing, air coupled testing, electromagnetic acoustic transducer (EMAT) testing and guided wave testing (GW).
Advanced Ultrasonic Methods
To overcome the limitations of conventional UT, advanced methods are developed. These techniques, which are commonly used in various industries, include:
Phased Array Ultrasonic Testing (PAUT)
Ultrasonic phased array is used to detect component failures such as cracks and flaws and can be applied for complex geometric parts, inspection of welds, thickness measurement and corrosion inspection. Special probes are utilised for inspection. These special probes are the conventional probe cut into several elements. Elements are acoustically insulated from each other and are pulsed in groups with pre-calculated time delay for each element. This provides the capability to modify refracted angle, allowing multiple angle inspection using a single probe.
The major advantage of this method is its higher speed and precision compared to the conventional UT.
Full Matrix Capture (FMC)
A variation of PAUT technique that uses the same probe but with a different data acquisition strategy that allows collection of data from every possible transmit-receive combination without the knowledge of the piece that is being inspected. The possibility of generating fully focused images from the acquired data that is processed in real-time and the ease of setting up are of the main advantages of this technique.
The main disadvantage of this technique is the huge size of the document files generated from the data. This limitation is overcome by the subsequent technique of virtual source aperture (VSA).
Visual Testing (VT)
The most common and basic method of non-destructive testing is visual inspection and evaluation of components, materials or structures. The ease of performing the inspection, as well as the low cost and minimal equipment necessary, makes this the primary method of NDT inspection. The inspector uses the naked eye to observe the component to detect discontinuity, corrosion, misalignment, damage or any other form of defects.
What can we do to help you?
Third party inspection
TWI services in Malaysia can provide a highly experienced and qualified engineering team to undertake third party NDT inspection, not only inside Malaysia, but also all across the Southeast Asia region.
Total Quality Inspection
We use a holistic approach for in-service inspection and improvement of critical structures and process plants. This is a part of our initiative to improve the performance of NDT, particularly in the oil, gas and petrochemical sector.
In-house training and certification of personnel
With more than 25 years of presence in the Southeast Asia, we have the expertise and capabilities to upskill and certify your NDT personnel to the CSWIP standards, which are in accordance with the requirements of EN ISO 9712.
For more information, please contact us at email@example.com