BACK GOUGING AND ITS APPLICATION TO GROOVE WELDS
A joint with a groove weld may include a requirement for back gouging. This operation is the removal of base and weld metal from the other side of a joint that has been groove welded. It is performed to ensure that there will be complete penetration when welded from that side. When back gouging is required, it is specified in the tail of the arrow with the words “back gouge,” Figure 13.19.
3RD OPERATION, U-GROOVE WELD (OTHER SIDE)
3RD OPERATION U-GROOVE WELD
SYMBOL SIGNIFICANCE
FIGURE 13.19 ■ Application of back gouging to groove welds.
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SEE NOTE |
Single groove joints may include the addition of backing material at the root of a joint for the purpose of supporting molten weld metal. The backing material may or may not be removed following completion of the weld. The supplementary “backing material” symbol is used with single-groove weld symbols. The symbol is placed on the side opposite the groove weld symbol, Figure 13.20. If the backing material is to be removed following the completion of the groove weld, an “R” notation is used and is located within the symbol; otherwise, the backing material may be left in place. Note that a tail is always used on the welding symbol when a backing or spacer material is used. A “See Note” reference is included in the tail to refer to a note on the drawing for the kind of backing or spacer material to be used and its dimensions, or this information is included in the tail itself. |
SIGNIFICANCE |
FIGURE |
3.20 ■ Application of backing material symbol with a V-groove weld symbol. |
BACKING AND SPACER MATERIAL SYMBOLS AND THEIR APPLICATION TO GROOVE WELDS Backing Material Symbol |
"R" SIGNIFIES BACKING MATERIAL TO BE REMOVED UPON COMPLETION OF GROOVE WELD |
SINGLE V-GROOVE - WITH BACKING MATERIAL |
-SINGLE V-GROOVE WELD |
SYMBOL |
X |
Spacer Material Symbol
A groove weld may include a metal strip or bar inserted at the root of the groove joint. It is used to maintain the root opening of a joint, or to bridge members of a joint with an exceptionally wide gap. After the initial weld is completed, spacers may be removed by back gouging and the second weld is completed from the opposite side or the spacer may become an integral part of the weld.
The “spacer material” symbol is used with a single or double groove weld symbol. It modifies the shape of the groove weld symbol by the addition of a rectangle within the groove symbol, Figure 13.21. Note that the spacer material symbol is shown centered on the reference line.
Typical applications of the spacer material symbol are shown in Figure 13.22.
SEE
1" 1" 4X2 |
NOTE
NOTE: SAE 20 SPACER MATERIAL
SYMBOL |
SPACER WELDED, IN PLACE |
1ST OPERATION |
WELD COMPLETED
г-WELD СОМІ
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2ND OPERATION
SIGNIFICANCE
L SPACER REMOVED V
BY BACK GOUGING COMPLETED SECOND WELD
SPACER MATERIAL SIGNIFICANCE |
3RD OPERATION 4TH OPERATION
FIGURE 13.21 ■ Application of spacer material symbol with bevel groove symbol (modified). |
DOUBLE V-GROOVE WELD |
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SAE 20 |
SPACER MATERIAL (INSERTED TO MAINTAIN ROOT OPENING) |
1" x 1" 8 2 |
SIGNIFICANCE
FIGURE 13.22 ■ Applications of spacer material symbol including size and kind of spacer material.