Civil Engineering Reference
In-Depth Information
of the surface used for markings should be the minimum required consistent
with adequate identification.
Fabrication aids and temporary attachments are any members, such as erec-
tion braces, sling stops, scaffolding supports, padeyes, dogs, walkways, and
others used for fabrication purposes. Material used for fabrication aids and tem-
porary attachments should comply with the project specification.
Fabrication aids and temporary attachments used for lifts during fabrication
should be designed and approved from the engineering office and should be
shown on the shop drawings and detailed in the fabrication procedures.
The quality-control supervisor should monitor the welding procedure speci-
fications and welder and tracker qualifications used to perform welding on
fabrication.
When fabrication aids and temporary attachments occur in areas that
become part of a completed weld area, within 300 mm (12 inches) of an inter-
secting weld, or in areas that require coating, the attachment should be removed
by oxy-fuel cutting a minimum of 3 mm (1/8 inch) above the surface of the
structural member and grinding the remainder flush with the surface of the
member. If the ground areas lie close to or underneath a weld, the surface
should be inspected using the magnetic particle test after grinding and before
the permanent weld is executed.
Fabrication aids and temporary attachments that occur in areas that do not
require coating and that are located more than 300 mm (12 inches) from an
intersecting weld should be seal-welded and should be removed to within 6 mm
(1/4 inch) of the surface of the member with sharp edges removed by grinding.
Oxy-fuel cutting may be used for the bulk removal of a fabrication aid or temporary
attachment, but it should not be used within 3 mm (1/8 inch) of the surface of the
underlying component. In general, fabrication aids and temporary attachments
should not be removed by hammering or oxy-fuel washing.
Heat Straightening
There is usually a heating procedure that should be prepared by the quality-
control supervisor based on the project specifications so that straightening of
members distorted by welding may be undertaken using localized heating.
The maximum temperature of the heated areas should be checked with heat-
indicating equipment.
Steel plate complying with the specification requirements may be rolled down
to a diameter-to-thickness ratio of 20:1 with no additional treatment. If a diameter-
to-thickness ratio of less than 20:1 is required, mechanical tests should demonstrate
that the steel retains its mechanical properties. Post-forming heat treatments, or hot
forming, can be necessary to ensure the properties are maintained.
The mechanical tests should be performed if the hot-rolled sections are
heated to straightening, to guarantee that the mechanical properties are main-
tained after forming and welding.
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