Page 233 - Handbook of Structural Steel Connection Design and Details

Welded Joint Design and Production

218 Chapter Three

for the 1G position, it may be advisable to qualify in the 2G position so
that additional usage can be obtained from this test plate.
In a similar way, D1.1-98, Table 4.7, defines what changes can be
made in the base metals used in production versus qualification test-
ing. An alternative steel may be selected for the qualification testing
simply because it affords additional flexibility for future applications.
If WPS qualification is performed on a nonprequalified joint geome-
try, and acceptable test results are obtained, WPSs may be written
from that PQR utilizing any of the prequalified joint geometries
(D1.1-98, Table 4.5, item 32).

3.5.6 Approval of WPSs
After a WPS is developed by the fabricator or erector, it is required to
be reviewed in accordance to D1.1 requirements. For prequalified
WPSs, the inspector is required to review the WPSs to ensure that
they meet all the prequalified requirements. For WPSs that are quali-
fied by test, the AWS D1.1-98 code requires these to be submitted to
the engineer for review.
The apparent logic behind the differences in approval procedures is
that while prequalified WPSs are based upon well-established time-
proven, and documented welding practices, WPSs that have been
qualified by test are not automatically subject to such restrictions.
Even though the required qualification tests have demonstrated the
adequacy of the particular procedure under test conditions, further
scrutiny by the engineer is justified to ensure that it is applicable for
the particular situation that will be encountered in production.
In practice, it is common for the engineer to delegate the approval
activity of all WPSs to the inspector. There is a practical justification
for such activity: the engineer may have a more limited understand-
ing of welding engineering, and the inspector may be more qualified
for this function. While this practice may be acceptable for typical
projects that utilize common materials, more scrutiny is justified for
unusual applications that utilize materials in ways that deviate sig-
nificantly from normal practice. In such situations, it is advisable for
the engineer to retain the services of a welding expert to evaluate the
suitability of the WPSs for the specific application.

3.6 Weld Size Determination
3.6.1 Strength of welded connections
A welded connection can be designed and fabricated to have a strength
that matches or exceeds that of the steel it joins. This is known as a
full-strength connection and can be considered 100% efficient. Welded
connections can be designed so that if loaded to destruction, failure

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