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Welding Joint Design andWelding Symbols
WORK DONE BY
RAJA KMECHANICAL ENGINEER(TEKLA STRUCTURES)MOB :- +971 0558384955.
After completing this chapter, you will be able to:◦ Sketch the five basic welding joints◦ Explain the factors that must be considered when
choosing a weld joint design◦ Discuss the factors to consider when selecting a weld
joint design◦ List and explain the information that can be included on a
welding symbol◦ Sketch a welding symbol and identify the components
Refers to the way pieces of metal are put together or aligned with each other
◦ The five (5) basic weld joint designs are:
Butt Joint
Lap Joint
Corner Joint
Tee Joint
Edge Joint
Name five basic weld joints that may be found in a weldment.
Two ways of fitting up an outside corner joint.
Open Corner Closed Corner
NOTE: "fillet weld" = a triangular shaped weld in a corner
Name three types of joints that use fillet welds?
Accessibility for welding Strength requirements Cyclic or static loading Material thickness Welding process to be used Material type Code Requirements Cost
Side Note: some considerations in selecting a type of joint to use on a fabrication.
Bevel Groove Vee Groove
J Groove
U GrooveSquare Groove
Name two edge preparations used with butt joints.
Edge preparations used with butt joints.
More Important Groove Preparations:
Bevel Groove – single and double
Vee Groove – single and double
1
2
1 2 3
4
Single V Groove
Double V Groove
Cost◦ A number of items affect weld cost
Even a slight change in groove angle can save time and money.
Weld Size Weld Faults
NOTE:While Leg Size is the usual method to specify and measure weld size, the Effective Throat is a more accurate measure of fillet weld strength!
EffectiveThroat
Actual ThroatLeg Size2
Leg Size1
TheoreticalThroat
Convexity
¼
How is the size of a fillet determined and what is used to measure it?
1. After selecting specified size gauge from set, measure Leg1
2. Measure Leg2
3. Verify throat with other side of gauge (face of gauge should touch weld)
L1
L2
3/8
How To Use A Fillet Gauge
Undercut – most predominant weld fault
◦ Fix: Short arc length, proper amperage and speed
Describe four typical faults in single-pass horizontal fillet welds.
Other typical faults in single-pass horizontal fillet welds:
Porosity:
Lack of shielding gasWet electrodeGreasy material
Other typical faults in single-pass horizontal fillet welds:
Slag Inclusion: Improper cleaning / removal of slag
Porosity
Undercut
Poor Fitup
Lack of Penetration
F = FilletG = Groove1 = Flat2 = Horizontal3 = Vertical4 = Overhead
G = Groove1 = Horizontal Rolled2 = Vertical5 = Horizontal Fixed6 = 45 Incline
Welding Symbols
Welding Symbols (cont’d.)
3 parts of the welding symbol body:
Arrow
Reference LineTail
Welding symbols ◦ Applied to reference
line at the base Reference lines have
an arrow side (near side) and other side (far side)
No size specified
What if the symbol were on this side?
Sketch the weld required by this symbol.
As you see in this example, the weld symbol usually looks like the weld cross
section shape!
Symbol must be above the reference line
indicating make weld on "Other Side" of joint from where arrow is pointing.
Complete the welding symbol that specifies the weld shown.
1/4
1/4 3/8
1/4
(1/4 x 3/8)
Nothing in the symbol specifies unequal leg size location.
If there are not obvious reasons to put larger leg on one side of joint (e.g. thicker metal), then it must be specified on drawing.
Complete the welding symbol that specifies the weld shown including dimension specifications.
1/4
1/4
3/8
3/8
1/4
3/8
Complete the welding symbol that specifies the weld shown including dimension specifications.
3/16
3/16
3/16 3 - 9
3/16
3 9
3/16
Sketch the weld required by this symbol including dimensions.
1/2
1/2 2 - 8
2 - 8
1/2
1/2
1/2
2 8
Sketch the weld required by this symbol including dimensions.
1/4
3/8
1 3
1 3
1/4 1 - 3
3/8 1 - 3
Complete the welding symbol that specifies the weld shown including dimension specifications.
1/4
1/2
1/2
2 3 1/2
1/2 x 1/4 2 – 3 ½
1/2 x 1/4 2 – 3 ½
Complete the welding symbol that specifies the weld shown including dimension specifications.
GTAW1/8
Process:Contour:
Finishing Method:
1/8
"TIG"FlatWelding
NOTE: The “Weld All Around” symbol is not required for pipe weld connections but may be included for clarity
In other cases, it is needed to specify that requirement
Sketch the weld required by this symbol including dimensions and notes.
GTAW1/8
Process:Contour:
Finishing Method:
1/8
"TIG"FlatWelding
NOTE: The “Flag” symbol.
Indicates field weld or on-site welding
Sketch the weld required by this symbol including dimensions and notes.
NOTE: The broken arrow line should be used to point at the side to be prepared.
NOTE: The vertical line must always be on the left side.
Complete the welding symbol that specifies the weld shown.
40
3/8
3/840°
Complete the welding symbol that specifies the weld shown including dimension specifications.
Process:Contour:
Finishing Method:
1/4FCAW
1/4 G
Flux CoredArc Welding
Convex
Grinding
Sketch the weld required by this symbol including dimensions and notes.
3/16
3/16
NOTE: Efforts should be made to avoid Hi/Lows for a smooth surface
SURFACING FUNCTIONS: Buildup Stainless Overlay Abrasion Resistant Overlay
Sketch the weld required by this symbol including dimensions.
2
1/81/8 2
Complete the welding symbol that specifies the weld shown including dimension specifications.
1 1/4 1/8 45
3/8 (1/2)
3/8
1/2SMAW
FCAW
SMAW3/8
1/8
45°13/8
1/2
2 3
Sketch the weld required by this symbol including dimensions.
THE ENDTHANK YOU
WORK DONE BY
RAJA KMECHANICAL ENGINEER(TEKLA STRUCTURES)MOB :- +971 0558384955.