Weld Testing is the use of visual and technological methods to test quality of welds, and to also confirm the presence, location and coverage of welds. Welds are used to join two or more metal surfaces. Because these connections may encounter loads and stress during a product’s lifetime, there is a chance they may fail if not created to proper specification.
Weld X-ray Testing
Weld X-ray Testing is typically performed by an NDT inspector on X-ray-based images or video. Industrial Radiography, or Weld X-ray Inspection, involves gamma radiation sources, most commonly Iridium-192 and Cobalt-60, which are used to inspect a variety of materials. The vast majority of Weld X-ray Testing concerns the testing and grading of welds on pressurized piping, pressure vessels, high-capacity storage containers, pipelines, castings, forgings, or any component that defects cannot be tolerated.
Liquid Penetrant Testing
Liquid Penetrant Testing, or dye penetrant inspection, is probably the most widely used NDT method. Welds are the most common item inspected, but plate, bars, pipes, castings, and forgings are often inspected using liquid penetrant examination. The test object or material is first cleaned and then coated with a visible or fluorescent dye solution. After a pre-selected time interval (dwell time, generally 7-10 minutes), the excess dye is removed from the surface, and then a developer is applied. The developer acts like a blotter and draws penetrant out of imperfections which are open to the surface. With visible dyes, the vivid color contrast between the penetrant and the developer makes the “bleedout” easy to see. With fluorescent dyes, an ultraviolet lamp is used to make the “bleedout” fluoresce brightly, thus allowing the imperfection to be seen readily.
Ultrasonic Testing uses the transmission of high frequency sound waves into a material to detect imperfections within the material or changes in material properties. One of the most useful characteristics of ultrasonic testing is its ability to determine the exact position of a discontinuity in a weld (ultrasonics for weld testing). The most commonly used ultrasonic testing technique is pulse echo wherein sound is introduced into the test object and reflections (echos) are returned to a receiver from internal imperfections or from geometrical surfaces of the part.
RNDT Inc. provides nondestructive testing, industrial radiography, magnetic particle testing and more. RNDT, Inc. is an A2LA ISO-17025 accredited commercial testing laboratory headquartered in Johnstown, PA. RNDT performs Weld Inspections, Weld Testing, Weld X-ray Testing, and other Weld Inspection Services. Our field & laboratory services are offered to all industries. RNDT provides nondestructive testing in the form of industrial x-ray testing (industrial radiography),positive material identification (PMI), liquid penetrant, magnetic particle and ultrasonic testing and visual (CWI) inspections to most all industries. RDNT employs highly trained and experienced nondestructive testing professionals that hold current certifications conforming to the requirements of ASNT SNT-TC-1A & CP-189, National Aerospace Standard NAS-410 Rev. 3, Pressure Equipment Directive 97/23 EC for PED projects. These certifications satisfy global requirements for nondestructive testing personnel.