Joint Preparation - GTAW pipe welding

• A. No groove required for any pipe size
• B. Groove is optional and only for thick walls
• C. Must be grooved before welding - single V - single U - single J
• D. Use multiple grooves on every joint

Answer: (C)

Joint preparation for GTAW pipe welding centers on shaping the pipe ends so the weld metal can fuse to both sides and reach the root. For butt joints, beveling the ends creates a groove that gives the welder a clear path for the root pass and enough access for proper penetration. The common single V, single U, and single J groove profiles are used to control root geometry, heat input, and throat size, which are critical for achieving a sound weld in the pipe thicknesses encountered in practice. The single V provides easy root access and a strong root bead; the curved U form lowers the risk of burn-through in thicker walls, while the J adds a small land to help with fit-up and smoother transitions. Because GTAW relies on precision and good fit-up, the edges must be grooved before welding rather than skipped. Therefore grooving is the standard practice for pipe butt joints in GTAW, with those groove types being the typical options.