How many weld passes are commonly made to complete a GTAW pipe weld?

• A. 2
• B. 3
• C. 4
• D. 5

Answer: (C)

In GTAW pipe welding, building the weld in multiple passes helps control heat input, ensure complete fusion, and shape the weld correctly. Four passes is the common sequence: a root pass to establish the seam and achieve proper penetration into the bevel; a hot pass to fuse the root and clean up any root irregularities while preparing for buildup; a fill pass to deposit metal and bring the weld to near final height; and a cap pass to finish the weld, shape the surface, and ensure full fusion at the outer edge. This approach balances penetration, distortion control, and meeting reinforcement requirements for typical pipe thicknesses. If the pipe is thicker or stricter codes apply, more passes may be used, but four passes are commonly taught as the standard for completing a GTAW pipe weld.