1. Terminology & Definitions
A Weld:
A union between materials caused by heat, and or pressure
A Joint:
A configuration of members

2. Joint Terminology
Edge
Open & Closed Corner
Lap
Tee
Butt
Cruciform

3. Welded Joint Terminology
Compound
Fillet
Butt
Spot
Edge
Plug

4. Butt Welds

5. Single sided Butt Preparations
Single sided preparations are normally made on thinner materials, or when access form both sides is restricted
Single
Single
Bevel
Vee
Single
Single J U

6. Double sided Butt Preparations
Double sided preparations are normally made on thicker materials, or when access form both sides is unrestricted
Bevel
Double
Vee
Double J
Double U
Double

7. Weld Zone Terms A B C D A, B, C & D = Weld Toes Weld zone Face
Weld metal
Fusion zone
Heat Affected Zone
Weld Junction
Root
A, B, C & D = Weld Toes

8. Butt Weld Features Weld cap width Excess Cap height
or Weld Reinforcement
Excess Root Penetration
Root bead width

9. Fillet Welds

10. Fillet Weld Leg Lengthsa b
a. = Vertical leg length
b. = Horizontal leg length

11. Fillet Weld Throat Thicknessb
a. = Design Throat Thickness
b. = Actual Throat Thickness

12. Deep Penetration Fillet Weld Featuresb
a. = Design Throat Thickness
b. = Depth of Penetration

13. Fillet Weld Dimensionsa
a = Design / Theoretical throat thickness s
s = Actual throat thickness b
b = Horizontal leg length c
c = Vertical leg length
e.g
Leg length = 6mm
Design Throat = 6mm x 0.7
Design Throat = 4.2mm
The leg length should be approximately equal to the material thickness
The design throat thickness is 0.7 of the leg length

14. Fillet Weld Profiles Mitre fillet Convex fillet
A concave profile is preferred for joints subjected to fatigue loading
Concave fillet

15. Welding Positions

16. Horizontal vertical: PC / 2G: Horizontal vertical: PB / 2F:
Welding Positions
Flat: PA / 1G:
Flat PA / 1F
Horizontal vertical: PC / 2G:
Horizontal vertical: PB / 2F:
Horizontal overhead
PD / 4F
Overhead
PE / 4G
Vertical downwards
PG / 3G
Vertical upwards
PF / 3G

17. Welding Positions PG / 5G PF / 5G PA / 1G 45o PC / 2G H-LO 45 / 6G
Weld: Flat
Pipe: rotated
Axis: Horizontal
PA / 1G
Weld: Vertical upwards
Pipe: Fixed
Axis: Horizontal
PF / 5G
PG / 5G
Weld: Vertical Downwards
Pipe: Fixed
Axis: Horizontal
45o
Weld: Horizontal vertical
Pipe: Fixed
Axis: Vertical
PC / 2G
H-LO 45 / 6G
Weld: Upwards
Pipe: Fixed
Axis: Inclined

18. Any Questions ?