<![CDATA[Shielded Metal Arc Welding (SMAW) is one of the most widely used welding processes for carbon steel piping due to its simplicity, cost-effectiveness, and reliability. However, welding defects may reduce joint integrity and compromise structural safety. This study aims to evaluate the surface quality of SMAW welded ASTM A106 Grade B pipe using Liquid Penetrant Testing (LPT), a non-destructive testing (NDT) method for detecting surface-breaking discontinuities. Pipe specimens with a diameter of 6 inches and a thickness of 6 mm were welded in the 5G position using E6010 electrodes for the root pass and E7018 electrodes for the fill and cap passes. The welded joints were visually inspected and subsequently examined using liquid penetrant testing at eight inspection locations before and after machining. The results showed that E6010 provided adequate root penetration, while E7018 produced smoother weld beads. The predominant surface defects identified were porosity, slag inclusion, and spatter. Machining reduced the number of detectable surface defects in most inspection areas, indicating the removal of superficial imperfections. Furthermore, appropriate selection of welding parameters, particularly welding current and electrode type, contributed to improved weld quality. The study demonstrates that liquid penetrant testing is an effective and practical technique for evaluating the surface integrity of SMAW welded ASTM A106 Grade B pipes and supports quality assurance in industrial welding applications]]>
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