The weld symbol indicates the type of weld and, when used, is a part of the welding symbol.
Weld Symbol: Weld symbols shall be as shown in figure below. The symbols shall be drawn “on” the reference line (for illustrative purposes shown dashed)

Weld symbol
Welding Symbol: The welding symbol consists of several elements (see Figure). Only the reference line and arrow are required elements. Additional elements may be included to convey specific welding information. Alternatively, welding information may be conveyed by other means such as by drawing notes or details, specifications, standards, codes, or other drawings which eliminates the need to include the corresponding elements in the welding symbol. All elements, when used, shall have specific locations within the welding symbol as shown in figure below.

Welding symbol
Example showing welding symbol with weld symbol is shown below.
Reference: AWS A2.4 literature
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KP Bhatt