CONVENTIONAL NON-DESTRUCTIVE TESTING
Inspection and testing
Non-Destructive Testing (NDT) are tests that are performed based on official regulations, international standards or specifications of accredited organizations and customers, through which you can know the condition of your assets, the integrity of its components, equipment or structures, for decision making documented from the data obtained.
This will result in minimization of maintenance costs, improvement of production processes and verification of reliable operating procedures appropriate to your processes.
NDT are inspection techniques that do not alter the physical, chemical or dimensional properties of the product or material being examined. They allow the detection of defects and damage and their sizing.
Delta Marine Scandinavia AB has an Inspection and NDT department integrated by highly qualified, experienced and specialized NDT Inspectors to perform inspections on the most complex elements, such as ultrasonic inspections on TKY joints of Jacket knots, and under the most demanding standards and criteria.
ULTRASOUND TESTING (US) is a method of inspection of materials and welds based on the phenomenon of reflection of acoustic waves when encountering discontinuities in their propagation. It is a volumetric test method that allows detecting internal discontinuities in the material or element under inspection as well as detecting changes in its properties.
Within the US test, the most commonly used technique is the echo-impulse technique. Sound is introduced into the element to be tested and the wave reflections (echoes) caused by the internal discontinuities or by the surface geometric characteristics of the element reach a receiver that transforms this mechanical pulse into an electrical pulse that is treated and amplified so that it can be displayed on the screen of the US equipment. The representation of these echoes provides the US inspector with information on the condition of the inspected material or item.
At the inspection level, they are mainly applied in:
- Welding inspection
- Detection of material heterogeneity as lamination in steels
- Quality control of structural materials
- Corrosion detection
- Thickness measurement
Delta Marine Scandinavia AB has state-of-the-art portable equipment for ultrasonic inspection.
Magnetic Particle Inspection
The MAGNETIC PARTICLE test allows the detection of surface or subsurface discontinuities in ferromagnetic materials.
It is based on the induction of a magnetic field in the material and the application of metallic particles on the surface. The discontinuities present alter the magnetic field flow causing leakage which leads to accumulation of particles in them producing a visible indication.
The magnetic particle test can use visible (coloured particles) or fluorescent media, with wet magnetic particles (suspended in a fluid) or in the form of dry powder.
They are mainly used in the inspection of:
- Welded joints
- Finished components
- Parts in service
- Hot rolled bars
- Castings and forgings
Delta Marine Scandinavia AB has portable equipment for field inspection and customer installations, AC and DC magnetic yokes.
Liquid Penetrant Inspection
The PENETRANT LIQUID TESTING (PL) allows the detection of surface discontinuities in non-porous materials, both metallic and non-metallic.
It is based on the phenomenon of capillarity. It consists of the application of a liquid with high wetting power (penetrant) on the surface to be tested, which penetrates the discontinuities by capillarity. It is necessary to clean its excess on the surface, to finally apply a developer that acts as a contrast background and is able to extract the penetrant retained in the discontinuities. The location of these is shown in this way.
They are used primarily for the detection of:
- Cracks open to the surface in manufacturing processes
- Porosity and inclusions
- Unmerged elements
- Defects occurring during component operation such as fatigue cracking
Delta Marine Scandinavia AB guarantees its customers safe detection by using only high quality products for testing and correct application.
Eddy Current Inspection
The INDUCED CURRENT test allows the detection of surface and subsurface discontinuities in conductive materials.
It is based on the principle of electromagnetism. It consists of the application of an alternating magnetic field on a conductive material generating an induced electric current on its surface whose flow is altered if there are discontinuities in the material.
They are used, among others, in the inspection of:
- Equipment for detection of damage, corrosion or cracking in tubular bundles
- Turbine shafts for crack detection
- Welding inspection of coated structures
- Cast or forged steel valves for crack detection in corrosion pitting areas
- Ship propellers to assess crack depths
- Bolt threads on components
Delta Marine Scandinavia AB has portable equipment for conventional eddy current inspection.
VISUAL TESTING is perhaps the most common method of inspection. Several factors are fundamental to its execution:
- The inspector’s knowledge of the production process, of the element to be inspected and its operation or destination, and of the standards and acceptance criteria to be applied.
- Correct illumination of the surface to be examined and the inspector’s field of vision.
- Have appropriate equipment or tools.
It is a fundamental test for determining the condition and quality of assets, whether they are products, components, structures, or materials and welds in production processes. In the latter case, it should always be complemented with other surface NDTs such as magnetic particles or penetrant liquids.
Visual inspection can be performed directly or indirectly, i.e. by the human eye itself or by using equipment with lens systems for remote remote inspection such as boresopes and videoendoscopies.
From Delta Marine Scandinavia AB we offer our clients expert inspectors in VISUAL INSPECTION for the execution of their own inspection in manufacturing processes, welding, life cycle of components and structures, among others, and the development of operating procedures and specifications according to the needs and requirements of their processes and projects.
For this purpose, the technical team are certified visual inspectors, certified welding construction inspectors, European Welding Experts and International Welding Engineers.
In addition, in collaboration with other entities, we have technological innovation to offer Remote Visual Inspection by means of drones.
Industrial Radiographic Inspection
INDUSTRIAL RADIOGRAPHY is a non-destructive test based on the ability of materials to absorb radiation.
A beam of ionizing radiation (X-rays or γ-rays generated by electrical equipment or radioactive isotopes) is passed through the component, element or material to be tested from one side. This radiation is more or less absorbed by the internal discontinuities according to their thickness, reaching the opposite face with different intensity and impressing a radiographic film. By developing this film, these discontinuities can be visualized and evaluated.
Delta Marine Scandinavia AB offers the following services within the field of Industrial Radiography:
- Radiography with portable Gammagraphy equipment with ionizing sources of Ir-192 and Se-75.
- Radiography with portable X-Ray equipment up to 360 KV.
- Radiography with portable gammagraphy equipment with Se-75 sources and SAFERAD radiation mitigation system.
- This equipment allows radiography minimizing exclusion zones of members of the public by means of a radiation protection or absorption system, whose shielding material is exclusively patented by SAFERAD, allowing the radiography to be performed in parallel with other activities, facilitating the assembly of large structures with a high volume of radiography in a very tight project execution time, as may be the case of the manufacture and assembly of large offshore modules.
DIGITIZATION OF RADIOGRAPHIC FILMS
radiographic films. For them, it has very high resolution industrial scanning equipment and editing software, DISTRIBUTOR FULL VERSION XVU and DISTRIBUTOR INTEGRATION, together with a module for ARRAY FILM DIGITIZER.
The digitization of radiographic films presents a number of advantages such as:
- Solves archiving and storage problems.
- Avoids loss of information due to lack of image quality due to film degradation over time.
- Allows the evaluation of discontinuities by remote technicians.