Visual inspection method allows to detect surface defects, deviations of the specified geometrical sizes and shapes. It is the simplest and most common NDT method, however, very effective for defect detection and prevention. The advantage of the method is the high speed of inspection, low labor and material consumption.  VT is used in advance of performing other control methods.  Disadvantage - the results of the inspection are subjective, very dependent on the human factor. In hard-to-reach places, additional equipment must be used – endoscopes, videoscopes and etc.