WELDING DESIGN, WELDING PROCEDURE AND PERFORMANCE QUALIFICATION
Edge Edge Prep Prepara arati tion on - Need Need Poor penetration Poor access at root Poor strength Good penetration Good access at root Good joint strength
Basic
Joint Types butt
lap
tee
corner edge
Applicable Welds for Squ Square Groove weld
Bevel Groove weld
J Groove weld
Butt
joint
V Groove weld
U Groove weld
Applicable Welds for Double
V Groove
weld
Double
weld
Butt
Double
joint
Bevel Groove
weld
U Groove
Double
weld
J Groove
Applicable Welds for Tee joint
Applicable Welds for Lap joint Fillet weld
Plug / slot weld
Spot / seam weld
Applicable Welds for Corner Joint
Butt Single V Groove weld
joint
Groo Groove ve angl angle e
Root
E
Root
face
Root
radius
gap
Double
V Groove weld Gro Groove angle gle Single U Groove weld Root
gap
Root
face
Weld Reinforcement
Correct
reinforcement
Excess reinforcement
Minimum cost
High cost
Good joint strength
Poor joint strength
Under reinforcement
Poor joint strength
Butt
joint joint Comp Complet lete e Joint Joint penetration
Weld from face side
Backing weld from root side
Back gouging
Back gouging from face side
Back weld
Weld from face side
Tee Joint
leg
throat
leg
Flat profile
throat
leg
leg
throat
leg
leg
Convex
Concave
profile
profile
Tee Joint Full penetration joint
Groove angle
leg = throat
leg = throat
Weld Welding ing Positi Position on Groov Groove e 1
G
3G
2G 4G
Weld Welding ing Positi Position on Groov Groove e
1
G
2G
5G
6G
45°
Weld Welding ing Positi Position on Fillet Fillet 1F
2F 3F
4F
Weld Welding ing Positi Position on Fillet Fillet 1F
2F
5F
Area A
Dilution
Area B Dilution
is the amo unt of base metal present in the weld metal and given by (Area B / (Area (Area A + Area B)) B )) Dilution
depends on the welding process and heat
input. High dilution alters the chemical composition of weld metal
Weld Metal Requirements
Matching strength with with the parent metal
Good notch toughness at the operating temperature
Corrosion
resistance
Creep
resistance for elevated temperat ure application
Resistance
to wear, erosion etc
Filler Metal Selection
Mechanical Mechanical / chemical properties re quired
Welding process Type
Metal to be joined and its thickness
Weld
of electrode, c urrent, power range
joint design and welding position
Shop or Field weld / s urface condition
Number
of passes / amo unt of weld metal
Welding Procedure Specification It
is a written doc ument that provides direction to the welder for making prod uction welds in accordance with with code re quirements. Any WPS must be qualified by the manufacturer. WPS
specifies the condition (ranges) under which welding m ust be performed called variables. WPS
addresses essential, s upplementar y essential and non essential varia bles
Purpose of WPS Qualification To
determine that the weldment is capa ble of providing the re quired properties for the intended application. WPS
establishes the properties of the weldment and not the skill of the welder.
Procedure Qualification PQR is a record of welding data to weld a test coupon. It also contains test res ults. Completed
PQR shall document all essential variables including ranges. PQR to be certified acc urate and shall not be subcontracted. If
more than one process is emplo yed then weld deposit thickness for each process and filler metal to be recorded.
Base
Metal Classification
Base metals classified into vario us P Nos depending on composition, welda bility & mechanical properties. P1 - P11
Steel
P21 - P25
Al alloys etc.
Group nos within P nos classif y metals for procedure qualification where notch toughness requirements are specified.
Filler Metal Classification F Numbers are based on usability characteristics i.e a bility of welders to make satisfactor y welds with given filler e.g. e.g. F1 - E XX20, 20, F2 - E XX12, F3 - E XX10, F4 - E XX18 etc. etc. A Numbers are based on chemical composition e.g. e.g. A1 - Mild ild stee steell A2 -
C
- Mo ste steel el etc. etc.
WPS for SMAW Essential varia bles Change
in qualified Thickness
Change
in P no
Change
in F no of filler metal
Change
in A no of filler metal
Change
in deposited metal thickness
ecrease Decrease Change
of more more than than 100° 100° F in prehea preheatt
in P WHT
WPS for SMAW Welded
Qualified
Px ± Px
Px ± Px
Px ± Py
Px ± Py
P3 ± P3
P3 ± (P3 / P1)
P4 ± P4
P4 ± (P4 / P3 / P1)
P5A ± P5A
P5A ± (P5A / P4 / P3 / P1)
P5A P5A ± (P4 (P4 / P3 / P1) P1)
P5A P5A ± (P4 (P4 / P3 / P1) P1)
P4 ± (P (P3 / P1)
P4 ± (P (P3 / P1)
Procedure Qualification Thickness limits T
(mm)
<1.6
Range
of T
max t
Tests
- 2T
2t
2T, 2 FB, 2
1.6 ± 10
1.6 - 2T
2t
-do-
10 - 19
4.8 - 2T
2t
-do-
19 - 38
4.8 - 2T
T
2t if t<19
2T, 4 SB
2T if t>19 >38
4.8 - 203
2t if t<19 203 if t>19
-do-
RB
Welding Performance Qualification The
performance qualification tests are intended to determine the a bility of welders to make sound welds A welder is qualified by radiography of a test coupon or by radiography of initial prod uction welding or by bend tests taken from a test coupon
Welding Performance Qualification Variables for SMAW Removal
of backing
Change
in Pipe diameter
Change
in P n umber
Change
in F
Change
in thickness of weld deposit
Change
in welding position
Change
in vertical v ertical welding
Number
Welding Performance Qualification Thk
(mm) (mm) Max Max tk of dep. dep. Metal Metal
<13
2t
>13
1FB, 1RB
Max to be welded
OD of test coupon
Test
Range
2SB
of OD qualified
<25
Size welded - unlimited
25 - 71
25 - unlimited
> 71
71 - unlimited
Welding Performance Qualification Welded Without
Qualified
Backing
Fx With
Fx
Backing F1
F1
F2
F2, F1
F3
F3, F2, F1
F4
F4, F3, F2, F1
F5
F5, F1
Welding Performance Qualification Weld
Plate & pipe >610 mm OD
Pipe of OD 71- 610 mm
Plate 1G
F
F
Plate 2G
F, H
F, H
Plate 3G Plate 4G
F, V F, O
F F
Pipe 1G
F
F
Pipe 2G
F, H
F, H
Pipe 5G
F, V, O
F, V, O
Pipe 6G
A ll
A ll
Thank you
