How many types of welding inspections are there?
There are five types of NDT welding inspection methods used in Canada. These include:
- Visual Testing (VT)
- Radiographic Testing (RT) or X-ray
- Ultrasonic Testing (UT)
- Magnetic Particle Testing (MT)
- Liquid Penetrant Testing (PT)
Visual inspection is the simplest form of non-destructive testing for welding inspection. VT requires the welding inspector to examine the weld visually to identify surface flaws.
Radiographic inspection, also referred to as X-ray, is also common and can be used to identify internal discontinuities in a weld. RT is a widely accepted inspection method and highly versatile.
Magnetic Particle inspection is used to detect flaws on the surface and just below the surface of a weld. This option is more sensitive than some NDT methods, meaning it can identify tighter cracks and flaws. However, MT can only be used on ferromagnetic materials.
Liquid Penetrant Testing is used to uncover surface cracks that cannot be detected by the naked eye. This non-destructive testing method can be used to easily detect flaws in materials that are complex in shape.
Ultrasonic weld inspection is used to uncover internal and surface flaws. This method is extremely sensitive, allowing for the detection of minor discontinuities. Phased array ultrasonic technology allows for even more advanced inspection. Phased Array Ultrasonic Testing, or PAUT, evaluates a component from multiple angles. As a result, complex components can be quickly and easily inspected.
