Visual inspection is one of the simplest non-destructive testing or the NDT methods used to check weld quality & defects. In this testing process, the professional welding inspectors in Launceston examine the welded joints with their naked eyes to find defects, surface discontinuities, and quality. In this blog, we are going to discuss this testing process.
Key advantages of the visual inspection process:
• Less expensive (Only labour expense included) • No equipment cost • No power requirement • Quick identification of surface discontinuities & welding defects • Easy to determine weld quality
What’s required for visual inspection?
The visual inspection is an equipment less NDT. So, there are some essential things required for this process. The welding inspectors should be trained properly. This is because good eyesight is highly essential for visual inspection (eyesight corrected to 20/40). Apart from that, the report should be recorded properly by the inspectors after inspection.
Visual welding equipment
Different types of welding equipment & tools are required for the visual inspection method. They include:
• Handheld fillet gauge (It measures weld flatness, convexity and concavity) • Pocket viewer protective lenses & shade lens for observing the welding operations • A magnifying glass for a clear view • Flashlight • Chisel and hammer for slag & spatter removal before the inspection • Temperature device (Pyrometer) for determining the interpass, preheating & post-heating temperatures. • Magnets to determine the material type being welded • Tape measure • Callipers
Stages of the visual inspection method
According to professional inspectors, visual inspection is mainly classified into 3 different stages. They include
Visual inspection before welding
• Check welding drawings • Check the position of weld & it corresponds to welding specifications • Check the direction of travel • Check welding symbols • Does the welding procedure align properly with the weld specifications & local codes?
Visual inspection during welding
• Check the electrons for storage, type & size. (A stabilizing oven is used to store lower hydrogen electrons) • Check root pass for susceptibility • Inspect the entire welding process • Ensure the weld is properly cleaned between each pass. • Look for craters that should be filled • Inspect the weld size & sequence. Gauges can be used to check the size
Visual inspection after welding
• Inspect weld against standards & codes • Check weld sizes with prints & gauges • Check contour & finish • Inspect cracks against welding standards • Check overlap • Inspect undercut • Find other minor welding defects • Provides final report after the inspection
Visual inspection is a cost-effective inspection process & it is considered as the initial stage of welding inspection. The importance of the visual inspection method is huge.