How many tack welds are specified for a 150 mm pipe in the 5G position?

Study for the Gas Metal Arc Welding Exam, including GMAW, FCAW, and MCAW methods. Use flashcards and multiple choice questions with hints and explanations for effective learning. Get ready for your welding certification!

Tack welds are used to hold the joint in the correct position before the full weld is made. In the 5G position, the pipe is fixed and rotated around its own axis, so heat from welding can cause distortion and movement if the joint isn’t secured. Placing tack welds at evenly spaced locations around the circumference creates a symmetric restraint that keeps the pipe and bevel alignment true as you complete the weld’s circumference. This even distribution minimizes the chances of rotation or misalignment, helps control distortion, and keeps the weld root in the correct position.

Choosing this mirrored, balanced pattern rather than clustering tacks in one area or leaving large gaps prevents uneven heating and movement. Too few tack welds can let the joint shift while you weld; too many can add unnecessary heat input and cleanup work without improving alignment. The goal is a stable, centered joint that remains true as you proceed with the main weld.