What is the first pass in a bevel pipe weld called?

The first pass in a bevel pipe weld is known as the root pass. This initial weld is critical because it establishes the foundation for the rest of the weld joint. The root pass is designed to fill the gap between the two pieces of pipe at their beveled edges, ensuring a solid connection that can be built upon with subsequent passes.

Welding processes often require careful attention to this initial step, as it must achieve a proper fusion between the base materials to avoid defects and ensure structural integrity. A well-executed root pass helps to maintain the alignment of the pipes and sets the stage for the fill and cap passes that follow.

The other terms listed, such as bevel pass, final pass, and root layer, do not accurately describe this primary step in the bevel welding process. The terminology used in welding is specific and understanding it is crucial for executing welding tasks effectively.