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understand basic weld symbols for learners.
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ELEMENTARY WELD ELEMENTARY WELD SYMBOLSSYMBOLS
Single Bevel Groove Weld
Single V Groove Weld with Broad Root Face
ELEMENTARY WELD ELEMENTARY WELD SYMBOLSSYMBOLS
Single Bevel Groove Weld with Broad Root Face
Single U Groove Weld
SUPPLEMENTARY SYMBOLSSUPPLEMENTARY SYMBOLS
Toes blended smoothly
Permanent Backing Strip
M
Removable Backing Strip
MR
SUPPLEMENTARY SYMBOLSSUPPLEMENTARY SYMBOLS
Tail Optional)
Sequence of Information in the Tail
• Process (as per ISO 4063)
• Acceptance Level (as per ISO 5817 or ISO 10042)
• Working Position (as per ISO 6947)
• Filler Materials (as per ISO 544 or ISO 2560 or ISO 3581)
EXAMPLES OF APPLICATIONEXAMPLES OF APPLICATION
Method of representation
Weld Joint
Arrow Line
Reference Line (Continuous)
Reference Line (Dashed)
EXAMPLES OF APPLICATIONEXAMPLES OF APPLICATION
Which is the Other Side in this case?
Side A
Side C
Side B
Side D
DIMENSIONING OF WELDSDIMENSIONING OF WELDS
Intermittent Fillet Welds
l (e) l (e)
z n x l (e)
z n x l (e)
DIMENSIONING OF WELDSDIMENSIONING OF WELDS
Staggered Intermittent Fillet Welds
z n x l (e)
z n x l (e)
l (e) l (e)
l (e) l (e)
Edge Preparation - NeedEdge Preparation - Need
Poor penetration
Poor strength
Good penetration
Good strength (100% joint efficiency)
Edge PreparationEdge Preparation
Factors which influence choice of edge Factors which influence choice of edge preparationpreparation
- Thickness- Thickness
- Material- Material
- Welding process- Welding process
- Extent of penetration required- Extent of penetration required
- Welding distortion- Welding distortion
- Cost - Cost
Applicable Welds for Butt Applicable Welds for Butt jointjoint
Square Groove weld V Groove weld
U Groove weldBevel Groove weld
J Groove weld
Applicable Welds for Butt Applicable Welds for Butt jointjoint
Double V Groove weld
Double U Groove weld
Double Bevel Groove weld
Double J Groove weld
Applicable Welds for Lap Applicable Welds for Lap jointjoint
Plug / slot weldSpot / seam weld
Fillet weld
Weld ReinforcementWeld Reinforcement
Correct reinforcement
Minimum cost
Good joint strength
Excess reinforcement
High cost
Poor joint strength
Under reinforcement
Poor joint strength
Butt joint – Complete Joint Butt joint – Complete Joint penetrationpenetration
Weld from face side
Back gouging
Back weld
Butt joint – Complete Joint Butt joint – Complete Joint penetrationpenetration
Backing weld
Back gouging
Butt joint – Complete Joint Butt joint – Complete Joint penetration (welding from one penetration (welding from one
side)side)
TIG / SMAW welding
Consumable guide
Butt Joint – Double V grooveButt Joint – Double V grooveLess weld metal
Less distortion
Higher edge preparation cost
Better for thickness > 20 mm
More weld metal
More distortion
Lower edge preparation cost
Better for thickness < 20 mm
Double V groove
Single V groove
Butt Joint – U grooveButt Joint – U groove
Good access at the root
Less weld metal
Higher edge preparation cost
Better for thickness > 40 mm
Groove angle
Root faceRoot gap
Root radius
Butt Joint – Bevel grooveButt Joint – Bevel groove
Double bevel groove
Single bevel grooveBevel angle 40 to 50°
Difficult to approach the root
Weld defects
Back gouging to remove root defects
Good weld quality
Butt Joint – J grooveButt Joint – J groove
Good access at the root
Back gouging and back welding to get good weld quality
Less weld metal
Higher edge preparation cost
Better for thickness > 40 mm
Tee Joint – Full strength jointTee Joint – Full strength joint
leg
leg throat
throat = 0.707 x leg
leg = 1.414 x throat
In a full strength joint, leg = 0.75 x thickness
Tee Joint – Full penetration jointTee Joint – Full penetration joint
leg = throat leg = throat
45° or 60°
Tee JointTee Joint
Theoretical throat
Actual throat
AWS D 1.1 recommendation when gap > 1.6 mm – to increase leg size of fillet by the amount of gap
Lap JointLap Joint
AWS D 1.1 recommendation
Overlap = 5 x thickness (1 inch minimum)
Gap between mating faces = 1.6 mm max
overlap
Welding Positions – GrooveWelding Positions – Groove
Position Inclination of axis Rotation of face
Flat 0° to 15° 150° to 210°
Horizontal 0° to 15° 80° to 150°
210° to 280°
Overhead 0° to 80° 0° to 80°
280° to 360°
Vertical 15° to 80° 80° to 280°
80° to 90° 0° to 360°
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