Unit 16 Groove Welds 205 General Use of Groove Weld Symbol Different conventions are used for groove weld- ing symbols depending on the dimensions that are specified and the information required. As previously discussed, dimensions for the preparation of groove welds are shown on the same side of the reference line as the weld symbol. See Figure 16-9. This exam- ple shows a J-groove weld. The information specified includes the depth of preparation, groove angle, and root opening. A dimension not in parentheses on the left of a bevel-, V-, J-, or U-groove weld symbol (in cases where the effective throat is not specified, or is speci- fied elsewhere on the print) indicates the size of the weld preparation only, Figure 16-6. No such dimen- sion is needed with a square-groove weld. Optional groove preparation with complete penetration is indicated when the letters CJP are shown in the tail of the reference line. No weld sym- bol is used, as in Figure 16-7. The weld size of a flare-groove weld is consid- ered only to the tangent point (the point where the curved surfaces meet), Figure 16-8. Double-groove welds are dimensioned on both sides of the reference line if no general note appears on the print, Figure 16-10. If the welds differ in size, they are dimensioned as in Figure 16-11. Groove welding symbols will not include dimensions when a general note determining groove weld size appears on Figure 16-9. Specifications for the preparation of an arrow side J-groove weld. 0 30° 3 4 30° 0 3 4 30° 0 3 4 Depth of preparation Root opening Groove angle Desired preparation Symbol Figure 16-10. Unless there is a general note on the print, double-groove welds are dimensioned on both sides of the reference line. 2 2 30° 30° 0 2 2 0 0 30° 30° R = User's standard Desired weld Symbol R R Figure 16-6. Weld preparation only is indicated if no dimension is in parentheses to the left of the bevel-, V-, J-, or U-groove weld symbol. 30° 7 8 30° 7 8 Joint preparation Symbol Figure 16-7. The letters CJP in the tail of the reference line indicate optional groove preparation with complete weld penetration. CJP Desired weld Symbol Figure 16-8. Flare-groove weld size extends only to the tangent points of the joint members. E S S(E) Desired weld Symbol S = Depth extends from point of tangency to top of member E = Effective throat