Page 228 - Handbook of Structural Steel Connection Design and Details

Welded Joint Design and Production

Welded Joint Design and Production 213

the minimum requirements of the code may not be adequate under all
circumstances. Additional requirements can be communicated
through the WPS, such as recommendations imposed by the steel pro-
ducer, electrode manufacturer, or others can and should be documented
in the WPS.

3.5.3 Prequalified welding procedure
specifications
The AWS D1.1 code provides for the use of prequalified WPSs.
Prequalified WPSs are those that the AWS D1 Committee has deter-
mined to have a history of acceptable performance, and so does not
subject them to the qualification testing imposed on all other welding
procedures. The use of prequalified WPSs does not preclude their
need to be in a written format. The use of prequalified WPSs still
requires that the welders be appropriately qualified. All the work-
manship provisions imposed in the fabrication section of the code
apply to prequalified WPSs. The only code requirement exempted by
prequalification is the nondestructive testing and mechanical testing
required for qualification of welding procedures.
A host of restrictions and limitations imposed on prequalified weld-
ing procedures do not apply to welding procedures that are qualified
by test. Prequalfied welding procedures must conform with all the
prequalified requirements in the code. Failure to comply with a single
prequalified condition eliminates the opportunity for the welding pro-
cedure to be prequalified. The use of a prequalified welding procedure
does not exempt the engineer from exercising engineering judgment
to determine the suitability of the particular procedure for the specific
application.
In order for a WPS to be prequalified, the following conditions must
be met:
The welding process must be prequalified. Only SMAW, SAW,
GMAW (except GMAW-s), and FCAW may be prequalified.
The base metal/filler metal combination must be prequalified.
The minimum preheat and interpass temperatures prescribed in
D1.1-98 must be employed.
Specific requirements for the various weld types must be main-
tained. Fillet welds must be in accordance with D1.1-98, Section 3.9,
plug and slot welds in accordance with D1.1-98, and groove welds
in accordance with D1.1-98, Sections 3.11 and 3.12, as applicable.
For the groove welds, whether partial joint penetration or complete
joint penetration, the required groove preparation dimensions are
shown in the code.

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