Radiographic Testing (RT) in Belgium
Industrial radiography uses X-rays or gamma rays to produce an image of the internal structure of a component. This benchmark volumetric method enables direct visualisation of internal defects such as porosity, inclusions, blowholes and lack of fusion.
What is Radiographic Testing?
Radiographic testing (RT) is a volumetric non-destructive testing method that uses the penetrating power of ionising radiation — X-rays or gamma rays — to create an image of the internal structure of a component. The principle is analogous to medical radiography: a beam of radiation passes through the component under test and is attenuated differently depending on the thickness and density of the material traversed. An internal defect (cavity, inclusion, lack of material) locally modifies the absorption of the radiation, creating contrast on the detector placed behind the component. This detector may be a silver-halide radiographic film (conventional radiography) or a digital sensor (computed radiography CR / digital radiography DR).
X-rays are produced by an electrical generator (X-ray tube) whose energy and output can be adjusted according to the thickness and nature of the material to be radiographed. Gamma rays are emitted by sealed radioactive sources (Iridium-192, Cobalt-60, Selenium-75) which offer the advantages of portability and no need for electrical power, making them particularly suited to on-site inspections in challenging industrial environments. The choice of radiation source depends on the thickness to be penetrated, the required resolution and logistical constraints.
LCNDTEST holds all the necessary authorisations and licences to perform industrial radiography in Belgium safely and in full regulatory compliance. Our operators are trained in radiation protection and hold the certifications required by the FANC (Federal Agency for Nuclear Control). We perform radiography using both film and digital techniques for the inspection of welds, castings and any component requiring a high-quality volumetric examination.
Inspection Methodology
Performing an industrial radiograph requires meticulous preparation that addresses both technical and radiation protection aspects. A shot plan is established in advance, defining the source position, the film or detector placement, the exposure parameters (voltage, current, exposure time for X-rays; source-to-film distance and exposure time for gamma sources), as well as the required image quality. Standardised image quality indicators (IQIs) are placed on the component to verify the radiographic sensitivity achieved.
On-site implementation requires the establishment of a demarcated safety perimeter, the dimensions of which are calculated based on the source used and the dose rate. Only authorised personnel are permitted to access the controlled area during the exposure. Radiographic exposures are often performed outside working hours or during production shutdowns to minimise constraints on surrounding activities. Each operator wears an individual dosimeter and a radiation survey meter is used to verify the limits of the safety perimeter.
After exposure, films are developed under controlled conditions (temperature, development time, fixing bath) or, in the case of digital radiography, images are processed by the acquisition software. Interpretation of the radiographs is performed by a Level 2 or Level 3 certified technician, on a calibrated film viewer for films or on a certified high-resolution monitor for digital images. Each defect is identified, located, sized and evaluated against the applicable acceptance criteria (EN ISO 10675-1 for steels). A comprehensive report accompanied by the radiographs is provided to the client.
Industrial Applications
- Inspection of butt welds on piping, vessels, pressure equipment and metallic structures
- Inspection of castings in foundries for the detection of shrinkage cavities, blowholes and sand inclusions
- Inspection of welded joints on gas and oil transport pipelines (in-service and construction welds)
- Verification of component integrity in the petrochemical, chemical and energy industries
- Inspection of complex assemblies and geometries that are difficult to access with ultrasonics
- Fabrication compliance inspection in accordance with ASME, EN 13480, EN 13445, EN 12952 and EN 12953 codes
Advantages of Radiographic Testing
- Produces a permanent, archivable image of the inspected volume, constituting objective documentary evidence
- Excellent detection sensitivity for volumetric defects (porosity, blowholes, inclusions, shrinkage cavities)
- Benchmark method in numerous international codes and standards for the qualification of critical welds
- Applicable to a wide range of materials and thicknesses (from a few millimetres to several hundred millimetres)
- Digital radiography offers reduced exposure times, advanced image processing and simplified archiving
Reference Standards
EN ISO 17636-1 (film) • EN ISO 17636-2 (digital) • EN ISO 10675-1 • EN ISO 19232 (IQI) • ASME Section V Article 2 • EN ISO 5579
Frequently asked questions
Radiographic testing is a volumetric NDT method that uses X-rays or gamma rays to create an image of the internal structure of a component. A beam of ionising radiation passes through the part and is attenuated differently depending on material thickness and density. Internal defects such as porosity, inclusions or lack of fusion appear as variations in contrast on a radiographic film or digital detector placed behind the component, providing a permanent visual record of the inspection.
Film radiography uses traditional silver-halide films that are exposed and chemically developed, producing a physical radiograph that is viewed on a calibrated film illuminator. Digital radiography uses electronic detectors (computed radiography plates or flat panel detectors) that produce a digital image, offering benefits such as shorter exposure times, enhanced image processing capabilities, easier archiving and the elimination of chemical processing. Both techniques are recognised by international standards such as EN ISO 17636.
Industrial radiography involves ionising radiation and is subject to strict safety regulations. In Belgium, operations are governed by the FANC (Federal Agency for Nuclear Control). Requirements include licensed and trained operators wearing individual dosimeters, a demarcated safety perimeter with controlled access during exposures, radiation survey meters to verify perimeter boundaries, and exposures often scheduled outside normal working hours to minimise impact on surrounding personnel. All operators must hold valid radiation protection certifications.