Advanced nondestructive technologies, compared to the traditional methods, use more advanced equipment, technology, and complex processes. The advantages of NVI’s advanced radiography services are clear—shorter exposures translate into increased safety and decreased downtime. NVI offers Advanced Radiography testing to all materials that need NDT inspection to meet the compliance codes, standards, regulations or your company’s specifications.
X-Ray Pipeline Crawlers
The X-Ray Pipeline Crawler is utilized when conditions are harsh, difficult or dangerous to human inspectors. This method remotely operated by a trained technician is used to observe the status of the weld in long-distance pipelines as well as speeds up the process of inspecting welds using conventional film. These crawlers produce a higher-quality image compared to gamma rays used in traditional radiography and require a smaller barricaded area and a shorter shot time.
Computed Radiography is a form of digital radiography that uses a reusable imaging plate in the place of film. Once the plate is exposed, it is scanned, and the image is captured, which then is transferred to the high-depth monitor designed solely for viewing the quality of the weld. The screen plays a huge role in this process because the sharpness of the image relies on the monitor’s resolution. After about a minute, the images are ready to be evaluated. This method allows for a wider dynamic range and enhanced measurements for corrosion that is not possible with conventional film. Compared to traditional radiography, this approach is faster and offers more convenient and reliable ways to replace film. Some of the advantages of computed radiography include a reduction of retakes, the long lifespan of the imaging plates, the image quality, as well as many others.
Real-time Radiography is the fastest and safest form of radiography. Rather than film or an imaging plate, real-time digital radiography uses a detector panel. As a result, technicians can examine the image in real time and add exposure time if it would improve image quality. As with computed radiography, images can be recorded electronically, sparing clients the need to store large volumes of film and making retrieving information much simpler.
Automated Ultrasonic Testing (AUT)
Automated Ultrasonic Testing is a method that uses scanners that travel around the weld to indicate and map out the location, size, and shape of the present flaws or corrosion areas. While the scanner is in motion, the scans become visible on a computer inside of the truck for review on the spot. NVI used automated systems to test components while they are in service. They can be accomplished using crawlers, robotic vehicles, or track systems. The advantages of this technology include speed, accuracy, and broad area coverage.
The phased array transducer consists of multiple aligned transducers (elements). Each element is pulsed individually to create various angles. As a result, the beam from a phased array probe can be moved (rastered) electronically (E-scan) and focused, without moving the probe. The beam can be swept through many angles at the same time (S-scan) and each angle focused at a specific depth. Weld flaw detection is the primary application; however NVI uses phased array for wall-thickness measurements and corrosion detection. Because it is safe to be used alongside other crafts, phased array is a good alternative to radiography. A primary advantage is, like radiography, phased array provides a permanent electronic record for review/auditing of results.
Positive Material Identification (PMI)
NVI uses PMI for chemical analysis of welding consumables. These tests often form the basis of materials traceability reports for fabrication clients who have purchased stock material or wish to identify materials in inventory.
X-Ray Fluorescent – When a material is bombarded with high-energy X-rays, each constituent element emits characteristic secondary X-rays. These secondary emissions can be measured, revealing the percentage of each element present. The advantage of this technology is that it is portable and quick. X-ray fluorescence is a convenient system – the equipment can be contained in a handheld gun – but it cannot measure carbon content. It is, however, an excellent option for alloyed steels.
Optical Emission Spectroscopy – At NVI, this is the technique of choice for analyzing high-carbon steels. This technique can identify every element on the periodic table, but it requires a large, bulky machine. The spectroscope generates an electric arc and computes the composition of metal by measuring the characteristic light intensity that elements produce when they are heated.
Ferrite testing is used to inspect stainless steel and duplex stainless steel welds, which are prone to problems with magnetism. NVI uses a handheld ferritoscope to determine the ferrite content of the metal. A low reading could indicate cracking in the weld, while a high reading could reveal lowered corrosion resistance.
NVI provides a full service of metallurgical laboratory testing methods that include Bend Test, Tensile Test, Impact Test, Nick Break Test, Hardness Test, and Ferrite Test. The procedures that are done on site for this service consist of Mirco/Marco structure analysis, PMI, IGCC Evaluation, Fatigue, and Fracture Analysis, and Creep Evaluation.
All types of failures are analyzed based on destructive and nondestructive testing. In accordance with all National, International and Customer Specification and Codes including; ASME, AWS, API, ANSI, and Military Standards.
Our onsite mobile welder qualification labs allow our customers to save valuable time on projects by testing welders on site with immediate results. Our labs are equipped with all beveling, tensile, bending, and associated equipment to get your welders out of the lab and into the field.