Section IX of the ASME Boiler and Pressure Vessel Code
forms listed below form the basis for verifying welding procedures and welder
- welder performance qualification
are three steps in qualifying welders and welding procedure specifications to
Section IX of the ASME Boiler and Pressure Vessel Code (BPVC).
prepare a welding procedure specification (WPS). The WPS
the minimum requirements that are specified by the code. The WPS provides
guidance for welding by specifying ranges for each variable.
Second, a procedure qualification record (PQR) is used to verify the WPS.
The WPS is qualified by welding procedure qualification test coupons. The
variables and tests used are recorded on a PQR.
the performance of the welders is verified by welding performance qualification
test coupons. The variables and tests used with the particular variable
ranges qualified are recorded on a welders performance qualification (WPQ)
way of conceptualizing these requirements is shown below:
Outline of Articles
in ASME Section IX
An abbreviated summary
of items covered in ASME Section IX is provided below
I - Welding General Requirements QW-100
Article I covers the scope of
ASME Section IX, the purpose and use of the WPS, PQR
and WPQ, responsibility, test positions, types and purposes of tests and
examinations, test procedures, acceptance criteria, visual examination, and
II - Welding Procedure Qualifications QW-200
Article II covers the rules for the preparation of WPS and PQR.
Each process is listed separately in QW-250 with the essential,
supplementary essential, and nonessential variables.
WPS shall specify a value or range for each essential, nonessential and, when
necessary, each supplementary essential variable listed for each welding
process. The PQR shall record the
value for each essential and, when necessary, each supplementary essential
a change is made in an essential variable, the WPS must be revised, and
requalified with a new PQR, unless the revision can be supported by an existing
when the code requires notch-toughness,
supplementary essential variables become additional essential variables. When
a change is made in a supplementary essential variable, the WPS must be revised,
and requalified by a new PQR, unless the revision can be supported by an
existing PQR for notch-toughness applications.
III - Welding Performance Qualifications QW-300
III covers the preparation of WPQ records. Each
welding process is listed separately in QW-350 with the essential variables for
welding performance. The WPQ form must record a value for each essential
variable used and must list a range qualified for each of these essential
III covers responsibility, type of tests, records, welder identification,
positions, diameters, expiration and renewal of qualifications.
Welders and Welding Operators may be qualified by visual and mechanical
tests, or by radiography of a test coupon, or by radiography of the initial
IV - Welding Data QW-400
IV covers welding variables that are used in the preparation and qualification
of the WPS, PQR or the WPQ as applicable. Some of the welding variables are
Article IV also includes assignments of P-Numbers (ASME base materials),
S-Numbers (other materials), F-Numbers (grouping of filler metals) and A-Numbers
(weld metal chemical analysis).
for WPS qualification thickness limits and tables for WPQ thickness and diameter
limits are also included. There are
tables for welding positions signifying
that a welder who qualifies in a particular position is qualified to weld within
a range of positions as appropriate.
test coupons, the removal of test specimens, and the test jig dimensions are
V - Standard Welding Procedure Specifications (SWPS) QW-500
V covers rules for the adoption, demonstration, and application of the Standard
Welding Procedure Specifications, (SWPSs).
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