9: Non-destructive Examination

9.1 DISCONTINUITIES
Non-destructive Examination (NDE) is defined as those inspection methods,
which allow materials to be examined without changing or destroying their
usefulness. NDE is an integral part of the quality assurance program. A
number of NDE methods are employed to ensure that the weld meets design
specifications and does not contain defects. The inspector should choose an
NDE method capable of detecting the discontinuity in the type of weld joint
due to the configuration. Table 2 and Figure 11 lists the common types and
location of discontinuities and illustrates their positions within a butt weld. The
most commonly used NDE methods used during weld inspection are shown
in Table 3.