Visual Testing (VT)

Visual Testing (VT)

Visual inspection of welding can often be the easiest to perform and is usually the least expensive to conduct. If carried out correctly, this type of inspection can often be an extremely effective method of maintaining acceptable welding quality and preventing welding problems. There are many areas within the welding operation that can be verified and evaluated by this method of inspection.

When designing an inspection plan, we need to establish the most appropriate areas to apply our inspection. We need to consider the possibility of preventing welding related problems, rather than finding problems which may have already occurred. Non- destructive testing (NDT), which is typically used for the inspection of completed welds, is usually designed and conducted to find welding problems after the fact, when the weld is completed. Visual inspection can often be utilized to prevent welding problems from happening in the first place. The welding inspection function is often divided into three areas. First, and often the least utilized, is pre-weld inspection. This type of inspection can often provide us the opportunity to detect and correct unacceptable conditions before they develop into actual welding problems. Second, inspection during the welding operation can often prevent problems in the completed weld through verification of the welding conditions and procedural requirements. Third, post-weld visual inspection is a relatively easy method of conducting completed weld quality evaluation. We shall consider each of these inspection stages in more detail.