266
Gas Tungsten Arc Welding Handbook
Inspection Areas
GTAW welders need to ensure that all aspects of
the operation are performed correctly. At a minimum,
welders should check the following areas:
• Base material is as specifi ed.
• Joint design is as specifi ed and within
required tolerances.
• Filler metal type and size are correct.
• Required welding equipment is available
and operating satisfactorily.
• Tooling has been adequately tested to determine
that it will properly support the operation.
• Parts have been properly cleaned.
• Welder training or certifi cation is suffi cient
for the weld operation.
• Proper welding procedure is used and the
welding equipment is set up properly for the
operation.
• Inspections and tests required during
the welding operation are performed as
specifi ed.
• Completed weld has been inspected to ensure
that it will meet the visual requirements.
Additional nondestructive examination is
usually performed by other personnel.
Types of Inspection
Inspections are performed to determine whether
a weld meets expectations. Depending on the fi nal use
of the weldment, several types of inspections may be
required, ranging from simple visual inspection to
rigorous testing.
Nondestructive Examination (NDE)
Inspections and tests of a weld that do not
destroy any portion of the completed weld are called
nondestructive examination (NDE). Inspections and
tests that destroy the completed weld, or samples of
the completed weld, are called destructive tests.
Visual Test
A visual test (VT) is one of the most important
methods of inspection and is widely used for accep-
tance of welds. VT is also used to identify bad welds
before other more expensive or time-consuming
forms of inspection are performed. Visual inspection
is easy to apply, quick, and relatively inexpensive.
Visual testing equipment includes rulers, fi llet weld
gauges, squares, magnifying glasses, and reference
weld samples. Some of the various tools used in weld
inspection are shown in Figures 18-1, 18-2, and 18-3.
These tools include the following:
Bridge cam
gauge
Automatic
weld size gauge
V-WAC
gauge
Fillet
weld
gauges
Extension
mirrors
Optical comparator
w/ scale
Magnification
lenses
Figure 18-1. An inspection kit may include any of the tools shown here. These tools are used to inspect a variety of dimensions,
including material thickness, bevel angle, crown height, undercut, mismatch, fi llet weld leg length, and throat thickness. (Mark Prosser)