When would multiple reference lines be used?

• A. To designate welding location in the field
• B. To indicate a sequence of operations required by the joint
• C. To specify the welding process
• D. To show the finish type

Answer: (B)

Multiple reference lines on a joint drawing communicate the sequence of operations that must be performed to complete the joint. When a joint requires several steps—such as edge preparation, tack welds, successive welding passes, or post-weld treatment—the lines show the order and where each operation should occur. This helps the welder plan the work, maintain proper fit-up, and control distortion by doing steps in the correct sequence. Details like welding location in the field, the welding process, or the finish type are shown with different symbols or notes, not by these sequence lines.