Radiographic Testing (RT)

Radiographic Testing (RT)

Radiographic Testing (RT) is a non-destructive examination (NDE) technique that involves the use of either x-rays or gamma rays to view the internal structure of a component. In the oil&gas and petrochemical industry, RT is often used to inspect machinery, such as pressure vessels and valves, to detect for flaws. RT is also used to inspect weld repairs.

Compared to other NDE techniques, radiography has several advantages. It is highly reproducible, can be used on a variety of materials, and the data gathered can be stored for later analysis. Radiography is an effective tool that requires very little surface preparation. Moreover, many radiographic systems are portable, which allows for use in the field and at elevated positions

X-rays and gamma radiation have wavelengths shorter than 100 nanometres (nm). Energy, at these wavelengths, will penetrate solid material. The shorter the wavelength, the greater the penetration. Like visible light, X-rays and Gamma radiation also have a photochemical effect on silver halide and can therefore produce an image on film. Thus, by passing penetrating radiation through an object, and recording the emerging radiation on a film, a two dimensional picture of the differences in thickness or density of the object can be obtained. Hence, flaws in the object can be detected.