AWS Certified Welding Inspector — FundamentalsWelding SymbolsMedium

A CWI is inspecting a blueprint for a pressure vessel assembly. The welding symbol for a critical butt joint includes a supplementary symbol that is a circle intersecting the junction of the reference line and the arrow. What does this supplementary symbol signify?

  1. AWeld all around.
  2. BBacking bar required.
  3. CField weld.
  4. DMelt-through.
Show answer & explanation

Correct answer: C. Field weld.

The circle intersecting the junction of the reference line and the arrow is the standard supplementary symbol for a field weld. This means the weld is to be made at the site of final construction, not in the shop.

Why the other options are wrong

  • A. A circle at the junction of the reference line and arrow indicates a field weld, not weld all around.
  • B. Backing bars are indicated by a rectangle or specific joint preparation.
  • D. Melt-through has a different, specific symbol.

Field Weld Symbol

A supplementary symbol, a circle at the junction of the reference line and the arrow, indicating that a weld is to be made at the place of final erection or assembly, not in the shop.

  • Circle at arrow/reference line junction.
  • Indicates on-site welding.
  • Distinguishes from shop welds.

Memory trick: Supplementary symbols add extra instructions, like a field trip.

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