Case Study: Checking spots on weld seams using the right camera
A client recently noticed unexpected black marks during a visual inspection near the weld seams at a near 6 o’clock position. Eager to find out more, they asked us to bring down a piece of equipment capable of taking a closer look, after they had tried a visual inspection using a pushrod camera.
The VT100, or Versatrax 100, was a the perfect choice for this particular job. Capable of quickly configuring for a variety of pipe diameters, it also has three powerful inbuilt lights, a pan-tilt-zoom camera. The pan-tilt-zoom function made possible taking a directed and closer look at what appeared to be corrosion, a dent, or just a mark in the 6 o’clock position that was impossible to take a closer look with a pushrod camera.
One of the risks involved in weld seams on pipework is the compositional changes in the metal structure that occur during heating/welding, and differences in the compositional microstructure of the base metal and the weld. While ultrasonic testing or 3D stereo measurement can offer an in-depth analysis of weld seams, weld failures in pipework due to what is known as SSC (Selective Seam Corrosion) are extremely rare, and the best method of identifying them completely is to conduct a regular visual inspection.
The VT100 conducted a detailed inspection of the entire length of several jointed pipes and focused on the black marks originally identified. On closer inspection using the pan-tilt-zoom function, the marks were classified as minor, allowing the pipework to be deployed without risk (see images below).
Remote visual inspection devices like Robotic Crawlers and Video Borescopes are perfect for this kind of inspection and offer a solution for every variety of pipe type, diameter and location.