Transcript Chapter 5

Welding Joint Design and
Welding Symbols

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
Welding Joint Design & Welding Symbols – Chapter #5

Refers to the way pieces of metal are put together
or aligned with each other
◦ The five (5) basic weld joint designs are:
Welding Joint Design & Welding Symbols – Chapter #5
Name five basic weld joints that may be found in a weldment.
Butt Joint
Lap Joint
Corner Joint
Tee Joint
Edge Joint
Welding Joint Design & Welding Symbols – Chapter #5
FIGURE 5-1
Types of joints.
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Welding Joint Design & Welding Symbols – Chapter #5
Open Corner
Closed Corner
FIGURE 5-2 Two ways of fitting up an outside corner joint.
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FIGURE 5-3 Edge joints.
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Welding Joint Design & Welding Symbols – Chapter #5
Name three types of joints that use fillet welds?
NOTE: "fillet weld" = a triangular shaped weld in a corner
Welding Joint Design & Welding Symbols – Chapter #5
Side Note: some considerations in selecting a type of joint to
use on a fabrication.
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Accessibility for welding
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Strength requirements
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Cyclic or static loading
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Material thickness
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Welding process to be used
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Material type
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Code Requirements
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Cost
Welding Joint Design & Welding Symbols – Chapter #5
Name two edge preparations used with butt joints.
Bevel Groove
Vee Groove
J Groove
Square Groove
U Groove
Welding Joint Design & Welding Symbols – Chapter #5
Edge preparations used with butt joints.
Welding Joint Design & Welding Symbols – Chapter #5
More Important Groove Preparations:
Bevel Groove – single and double
Vee Groove – single and double
3D Welded Joints.pdf
Welding Joint Design & Welding Symbols – Chapter #5
Single V Groove
Double V Groove
1 2 3
1
4
2
Welding Joint Design & Welding Symbols – Chapter #5
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Cost
◦ A number of items affect weld cost
FIGURE 5-14 Even a slight change in groove angle can save time and money.
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Welding Joint Design & Welding Symbols – Chapter #5
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
Weld Size
Weld Faults
Welding Joint Design & Welding Symbols – Chapter #5
How is the size of a fillet determined and what is used to
measure it?
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!
Convexity
Leg Size2
Actual Throat
Effective
Throat
¼
Leg Size1
Theoretical
Throat
Welding Joint Design & Welding Symbols – Chapter #5
How To Use A Fillet Gauge
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
3/8
L2
Welding Joint Design & Welding Symbols – Chapter #5
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Undercut – most predominant
weld fault
◦ Fix: Short arc length, proper
amperage and speed
Welding Joint Design & Welding Symbols – Chapter #5
Describe four typical faults in single-pass horizontal fillet welds.
Welding Joint Design & Welding Symbols – Chapter #5
Other typical faults in single-pass horizontal fillet welds:
Porosity:
Lack of shielding gas
Wet electrode
Greasy material
Welding Joint Design & Welding Symbols – Chapter #5
Other typical faults in single-pass horizontal fillet welds:
Slag Inclusion: Improper cleaning / removal of slag
Welding Joint Design & Welding Symbols – Chapter #5
Undercut
Porosity
Poor Fitup
Lack of Penetration
Welding Joint Design & Welding Symbols – Chapter #5
F = Fillet
G = Groove
1 = Flat
2 = Horizontal
3 = Vertical
4 = Overhead
Welding Joint Design & Welding Symbols – Chapter #5
G = Groove
1 = Horizontal Rolled
2 = Vertical
5 = Horizontal Fixed
6 = 45 Incline
Welding Joint Design & Welding Symbols – Chapter #5
Welding Symbols
Welding Joint Design & Welding Symbols – Chapter #5
Welding Joint Design & Welding Symbols – Chapter #5
Welding Symbols (cont’d.)
3 parts of the welding symbol body:
Reference Line
Tail
Arrow
Welding Joint Design & Welding Symbols – Chapter #5
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Welding symbols
◦ Applied to reference
line at the base
 Reference lines have
an arrow side (near
side) and other side
(far side)
FIGURE 5-17 Designating weld location.
American Welding Society
Sketch the weld required by this symbol.
What if the symbol
were on this side?
No size specified
Welding Joint Design & Welding Symbols – Chapter #5
Complete the welding symbol that specifies the weld shown.
Symbol must be above
the reference line
indicating make weld on
"Other Side" of joint from
where arrow is pointing.
As you see in this example,
the weld symbol usually
looks like the weld cross
section shape!
Welding Joint Design & Welding Symbols – Chapter #5
Complete the welding symbol that specifies the weld shown
including dimension specifications.
1/4
(1/4 x 3/8)
Nothing in the symbol specifies
unequal leg size location.
1/4
1/4
3/8
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.
Welding Joint Design & Welding Symbols – Chapter #5
Complete the welding symbol that specifies the weld shown
including dimension specifications.
1/4
3/8
3/8
1/4
1/4
3/8
Welding Joint Design & Welding Symbols – Chapter #5
Sketch the weld required by this symbol including dimensions.
3/16
3/16
3/16
3
9
3/16
3/16
3-9
Welding Joint Design & Welding Symbols – Chapter #5
Sketch the weld required by this symbol including dimensions.
1/2
2-8
1/2
2-8
2
8
1/2
1/2
1/2
Welding Joint Design & Welding Symbols – Chapter #5
Complete the welding symbol that specifies the weld shown
including dimension specifications.
3/8
1/4
1-3
1-3
1
3
1/4
3/8
1
3
Welding Joint Design & Welding Symbols – Chapter #5
Complete the welding symbol that specifies the weld shown
including dimension specifications.
1/2 x 1/4
1/2 x 1/4
2–3½
2–3½
2
3 1/2
1/2
1/4
1/2
Welding Joint Design & Welding Symbols – Chapter #5
Sketch the weld required by this symbol including dimensions
and notes.
1/8
1/8
GTAW
"TIG"
Contour: Flat
Finishing Method: Welding
Process:
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
Welding Joint Design & Welding Symbols – Chapter #5
Sketch the weld required by this symbol including dimensions
and notes.
1/8
1/8
GTAW
"TIG"
Contour: Flat
Finishing Method: Welding
Process:
NOTE: The “Flag” symbol.
Indicates field weld or on-site welding
Welding Joint Design & Welding Symbols – Chapter #5
Complete the welding symbol that specifies the weld shown.
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.
Welding Joint Design & Welding Symbols – Chapter #5
Complete the welding symbol that specifies the weld shown
including dimension specifications.
3/8
40°
40
3/8
Welding Joint Design & Welding Symbols – Chapter #5
Sketch the weld required by this symbol including dimensions
and notes.
1/4
1/4
G
FCAW
Flux Cored
Process: Arc Welding
Contour: Convex
Finishing Method: Grinding
Welding Joint Design & Welding Symbols – Chapter #5
Sketch the weld required by this symbol including dimensions.
NOTE: Efforts should be made to avoid
Hi/Lows for a smooth surface
SURFACING FUNCTIONS:
 Buildup
 Stainless Overlay
 Abrasion Resistant Overlay
3/16
3/16
Welding Joint Design & Welding Symbols – Chapter #5
Complete the welding symbol that specifies the weld shown
including dimension specifications.
1/8
2
1/8
2
Welding Joint Design & Welding Symbols – Chapter #5
Sketch the weld required by this symbol including dimensions.
SMAW
1/2
3/8 (1/2)
1 1/4
FCAW
1/8
45
3/8
3/8
SMAW
45°
3/8
1
2
1/8
3
1/2
Welding Joint Design & Welding Symbols – Chapter #5