Visual Weld Inspection

Visual inspection (VT) is the most important and most frequently used method of weld examination—it catches over 75 percent of all weld defects when performed systematically. A qualified inspector examines welds before, during, and after welding. Before welding, the inspector verifies joint preparation, fit-up dimensions, cleanliness, and preheat temperature. During welding, the inspector monitors interpass temperature, electrode type, and welder technique. After welding, the inspector measures the completed weld against the code acceptance criteria using calibrated gauges.