2. ASME SEC IX
This Section is divided into four parts.
(1) Part QG contains general requirements for all material-joining
processes.(2013)
(2) Part QW contains requirements for welding.
(3) Part QB contains requirements for brazing.
(4) Part QF contains requirements for plastic fusing.(2013)
Precedence of Referencing Code/Standard/Specification to
This Code
Common terms relating to material joining processes are
defined in QG-109.
Whenever the word “pipe” is used, “tube” shall also be
applicable.
3. WPS
(a) Welding Procedure Specification (WPS). A WPS is a written qualified
welding procedure prepared to provide direction for making production
welds to Code requirements.
(b) Contents of the WPS. The completed WPS shall describe all of the
essential, nonessential, and, when required, supplementary essential
variables for each welding process used in the WPS. These variables are
listed in QW-250 through QW‐280 and are defined in Article IV, Welding
Data.
4. Procedure Qualification
The purpose of qualifying the procedure specification is to demonstrate that
the joining process is capable of producing joints having the required
mechanical properties for the intended application.
Qualification of the procedure specification demonstrates the mechanical
properties of the joint made using a joining process, and not the skill of the
person using the joining process.
The procedure qualification record (PQR) documents what occurred during
the production of a procedure qualification test coupon and the results of
testing that coupon.
As a minimum, the PQR shall document the essential variables applied
during production of the test joint, and the results of the required tests.
A procedure specification may be supported by one or more PQR(s), and
one PQR may be used to support one or more procedure specification(s).
5. Performance Qualification
The purpose of qualifying the person who will use a
joining process is to demonstrate that person’s ability to
produce a sound joint when using a procedure
specification.
The performance qualification record shall document the
essential variables for each process used to produce the
test coupon, the ranges of variables qualified, and the
results of the required testing and/or nondestructive
examinations.
The organization shall certify a performance qualification
record by a signature
6. Variables
Procedure specifications address the conditions (including ranges, if any) under
which the material joining process must be performed. These conditions are referred
to in this Section as “variables.”
Four Types of Variables:
Essential: Essential variables are conditions in which a change, as described in the
specific variables, is considered to affect the mechanical properties of the joint.
Before using a procedure specification whose essential variables have been revised
and fall outside their qualified range, the procedure specification must be requalified.
Supplementary Essential: When this section, the referencing Code, standard, or
specification requires toughness qualification of the material joining procedure, the
applicable supplementary essential variables shall also be addressed in the
procedure specification.
Non-Essential: Nonessential variables are conditions in which a change, as
described in the specific variables, is not considered to affect the mechanical
properties of the joint. A procedure specification may be editorially revised to change
a nonessential variable to fall outside of its previously listed range, but does not
require requalification of the procedure specification.
Special Process Variables. Special process variables are conditions that apply
only to special processes that are described in the Part that addresses those
processes. When these special processes are used, only the applicable special process
variables shall apply. A change in these process variables shall require requalification
of the procedure specification.
7. Definition
single‐welded joint: a joint welded from one side only.
backing: a material placed at the root of a weld joint for the purpose of
supporting molten weld metal so as to facilitate complete joint penetration.
The material may or may not fuse into the joint. See also retainer.
weld size:
for unequal leg fillet welds: the leg lengths of the largest right triangle
which can be inscribed within the fillet weld cross section.
groove welds: the depth of chamfering plus any penetration beyond the
chamfering, resulting in the strength carrying dimension of the weld.
8.
9. Welding Articles
Article I, Welding General Requirements
Article II, Welding Procedure Qualifications
Article III, Welding Performance Qualifications
Article IV, Welding Data
Article V, Standard Welding Procedure Specifications
13. Article II Procedure Qualification
Format of WPS/PQR
P-No, Group-No & notch Toughness Test
Combination of Welding Procedures.
QW-255 Description
Type of tests required
Weld Repair and Buildup.
Dissimilar Base Metal Thicknesses.
Limits of qualified positions for procedures
Applied linings
Joining of composite (clad metals)
Special Processes Variables in Welding(corrosion‐resistant and
hard‐surfacing weld metal overlays)
Welds with buttering
Temper bead welding
14. WPS Format
At Least shall Contain following Items:
Organization Name ---- By ----
Welding Procedure Specification No. ---- Date ----
Supporting PQR No.(s)
Welding Process(es) ---- Types (Automatic, Manual, Machine, or Semi-Automatic)
Joints (QW-402)
Base metals (QW-403)
Filler metals (QW-404)
Positions (QW-405)
Preheat (QW-406)
Post weld heat treatment (QW-407)
Time Range
GAS (QW-408)
Trailing
Electrical characteristics (QW-409)
Mode of Metal Transfer for GMAW (FCAW)
Technique (QW-410)
15. PQR Format
It Shall include following Items:
All Items Specified in WPS Plus following.(be careful that
in WPS limits are mentioned for Example Range of Base
Metal Qualification but in PQR the Precise amount shall
be Mentioned. )
Relevant QW-1XX from Article I which shows Result of
Test Which are necessary to Qualify Procedure
Welder’s Name ---- Clock No. ----- Stamp No. -----
Tests Conducted by ---- Laboratory Test No. ----
Organization ----Date ----- Certified by ---
16. P-No. and Group-No. & Notch- Toughness
To reduce the number of welding procedure qualifications required,
P‐Numbers are assigned to base metals dependent on characteristics such as
composition, weldability, and mechanical properties, where this can
logically be done.
for steel and steel alloys Group Numbers are assigned additionally to
P‐Numbers. These Group Numbers classify the metals within P‐Numbers
for the purpose of procedure qualification where notch‐toughness
requirements are specified.
17. Needed Definition
The F-number groupings are based essentially on their usability
characteristics, which fundamentally determine the ability of welders to
make satisfactory welds with a given process and filler metal. A complete
list of F-numbers for electrodes and welding rods is given in ASME Section
IX, Table QW-432.
The A-number grouping in ASME Section IX, Table QW-442 is based on
the chemical composition of the deposited weld metal. This grouping does
not imply that filler metals may be indiscriminately substituted without
consideration for the compatibility with the base metal and the service
requirements.
SFA No. are AWS AX.YZ Specifications which were accepted by ASME
committee and adopted with new designation without Any Changes in
content. For Example SFA 5.1 is the same AWS A5.1 Specification.
18. Definition (Continued)
Gases:
Shielding gas is the one emanating from the GTAW 'Tig' torch, or the
GMAW 'Mig/MAG' gun, to purge the area of the top of the weld
puddle..
Backing gas is the internal purge of a pipe or fitting, that keeps the back
side of easily oxidized metals from getting gross coats of oxidation
"sugaring" [looks like lumpy brown sugar]. Stainless, Titanium, Inconel
all require purging. ASME Sec. IX calls it "Backing Gas". All the 'field
hands' refer to it as a purge
23. AWS A5.32-section 9: When mixed gases are being analyzed, the volumetric
percentage of minor components shall be within ±10 percent relative to the
nominal percentage of the minor component of the classification
24. Limits of qualified positions for procedures: Unless
specifically required otherwise by the welding variables
(QW-250), a qualification in any position qualifies the
procedure for all positions. The welding process and
electrodes must be suitable for use in the positions
permitted by the WPS. A welder or welding operator
making and passing the WPS qualification test is qualified
for the position tested. see QW-301.2.
25. Article III
Type of test required
Groove weld performance
Fillet weld performance
Volumetric NDE for welder/Welding Operator performance
Type and quantity of tests
Qualification test coupons
Welding variable for performance
26. TYPE OF TEST REQUIRED
QW-302.1 Mechanical Tests. Except as may be specified for special processes
(QW-380), the type and number of test specimens required for mechanical testing
shall be in accordance with QW-452.
Groove weld test specimens shall be removed in a manner similar to that shown in
Figures QW-463.2(a) through QW-463.2(g).
Fillet weld test specimens shall be removed in a manner similar to that shown in Figures
QW-462.4(a) through QW-462.4(d) and Figure QW-463.2(h).
All mechanical tests shall meet the requirements prescribed in QW-160 or QW-180, as
applicable.
QW-302.2 Volumetric NDE. When the welder or welding operator is qualified by
volumetric NDE, as permitted in QW-304 for welders and QW-305 for welding
operators, the minimum length of coupon(s) to be examined shall be 6 in. (150 mm)
and shall include the entire weld circumference for pipe(s), except that for small
diameter pipe, multiple coupons of the same diameter pipe may be required, but the
number need not exceed four consecutively made test coupons.
The examination technique and acceptance criteria shall be in accordance with QW-191.
27. Groove Weld Performance
GENERAL NOTE: The “Thickness of Weld Metal” is the total weld metal thickness deposited by
all welders and all processes in the test coupon exclusive of the weld reinforcement.
NOTES:
(1) To qualify using positions 5G or 6G, a total of four bend specimens are required. To qualify
using a combination of 2G and 5G in a single test coupon, a total of six bend specimens are
required. see QW-302.3.
(2) Coupons tested by face and root bends shall be limited to weld deposit made by one welder
with one or two processes or two welders with one process each. Weld deposit by each welder
and each process shall be present on the convex surface of the appropriate bent specimen.
(3) One face and root bend may be substituted for the two side bends.
28. NOTES:
(1) When more than one welder and/or more than one process and more than one filler metal
F‐Number is used to deposit weld metal in a coupon, the thickness, t , of the weld metal in the
coupon deposited by each welder with each process and each filler metal F‐Number in
accordance with the applicable variables under QW-404 shall be determined and used
individually in the “Thickness, t , of Weld Metal in the Coupon” column to determine the
“Thickness of Weld Metal Qualified.”
(2) Two or more pipe test coupons with different weld metal thickness may be used to
determine the weld metal thickness qualified and that thickness may be applied to
production welds to the smallest diameter for which the welder is qualified in accordance with
QW‐452.3
(3) Thickness of test coupon of 3/4 in. (19 mm) or over shall be used for qualifying a
combination of three or more welders each of whom may use the same or a different welding
process.
32. Volumetric NDE for Welder Performance
Except for the special requirements of QW-380, each welder Alternative to mechanical and
visual test, may be qualified by volumetric NDE per QW-191 When making a groove
weld using SMAW, SAW, GTAW, PAW, and GMAW (except short‐circuiting mode for
radiographic examination) or a combination of these processes, except for P‐No. 21
through P‐No. 26, P‐No. 51 through P‐No. 53, and P‐No. 61 through P‐No. 62 metals.
Welders making groove welds in P‐No. 21 through P‐No. 26 and P‐No. 51 through P‐No.
53 metals with the GTAW process may also be qualified by volumetric NDE per QW-191.
Interpretation: IX-95-39
Subject: QW-304, Performance Qualification – Welders
Date Issued: January 6, 1997 File No: 96-331
Question (2): If a welder used GMAW (short-circuiting mode) for the root pass and SAW
for the hot and fill passes of test coupon, may the test coupon be testing using radiography
for the SAW portion of the weld, in accordance with QW-304 and QW-306?
Reply (2): Yes.
33. Type and Quantity of Tests
a minimum 6 in. (150 mm) length of the first production weld(s) made by a welder
using the process(es) and/or mode of arc transfer specified in QW-304 may be
examined by volumetric NDE.
(a) For pipe(s) welded in the 5G, 6G, or special positions, the entire production weld
circumference made by the welder shall be examined.
(b) For small diameter pipe where the required minimum length of weld cannot be
obtained from a single production pipe circumference, additional consecutive
circumferences of the same pipe diameter made by the welder shall be examined,
except that the total number of circumferences need not exceed four.
(c) The examination technique and acceptance criteria for production welds shall be
in accordance with QW-191
*: Specific Process which has special requirements per QW-380 are :
CORROSION‐RESISTANT WELD METAL OVERLAY
HARD‐FACING WELD METAL OVERLAY (WEAR RESISTANT)
CLAD MATERIALS AND APPLIED LININGS
FLASH WELDING OPERATOR
DIFFUSION WELDING OPERATOR
34. Welding Variable for Performance
These Variable were determined per relevant QW-35X for Each
Process which are shown together in Qw-416
Three of these variables are more important than others:
QW-403.18: a change from P-No.
QW-404.15: a change from F-No.
Qw-409.2: A change from globular, spray or pulsed spray transfer
welding to short circuiting transfer welding or vice versa.
35. NOTES:
(1) For description, see Section IV.
(2) Flux‐cored arc welding as shown in QW‐355, with or without additional shielding from an
externally supplied gas or gas mixture, is included.
36. QW-403.18 A change from one P‐Number to any other P‐Number or to a
base metal not listed in Table QW/QB-422, except as permitted in QW-423,
and in QW-420.
QW-423:
37.
38. QW-404.15 A change from one F‐Number in Table QW-432 to any other
F‐Number or to any other filler metal, except as permitted in QW-433.
QW-433:
39.
40.
41.
42. Article I
Welding General Requirements Contain following
Parts:
Weld Position &Test Position
Types and purposes of tests and examinations
Acceptance Criteria
Article I only Define all applicable test and general Note for
Preparation of Test Specimen and Does not Exactly Determine
which Test shall be used for Procedure qualification or
Performance Qualification. Also Acceptance Criteria is
Specified by Article I.
43. Types and purposes of tests
Mechanical tests
Tension Tests
Guided‐Bend Tests.
Notch‐Toughness Tests.
Visual Examination(Section V,
Article 6)
Liquid penetrant examination
Fillet‐Weld Tests.
Diffusion welding test
Volumetric examinations(RT &
UT)
Stud‐Weld Tests
Tube‐to‐tube sheet tests
Resistance weld testing
Laser beam welding (LBW) lap
joint tests
Flash welding
NOTICE: some Test like Visual and Macro Examination has Different ACC
Criteria for Procedure Qualification and Performance Qualification.
45. Fillet‐weld tests
Categories That Consider Tests:
Procedure Qualification (QW-451.3)
Macro- Examination Test
Performance Qualification (QW-452)
Macro- Examination Test
Fracture Test
*Mock Up can be in two types: Pipe to shape and
Plate to shape
47. Macro Examination Acceptance Criteria
Procedure Qualification: In order to pass the test
(a) visual examination of the cross sections of the weld metal
and HAZ shall show complete fusion and freedom from cracks
(b) there shall be not more than 1/8 in. (3 mm) difference in the
length of the legs of the fillet
Performance Qualification: In order to pass the test
(a) visual examination of the cross section of the weld metal
and HAZ shall show complete fusion and freedom from cracks,
except that linear indications at the root not exceeding 1/32 in.
(0.8 mm) shall be acceptable
(b) the weld shall not have a concavity or convexity greater
than 1/16 in. (1.5 mm)
(c) there shall be not more than 1/8 in. (3 mm) difference in the
lengths of the legs of the fillet
48. Size of Test Coupon For Performance
Qualification