Page 73 - Pipeline Rules of Thumb Handbook

60 Pipeline Rules of Thumb Handbook

Figure 1. Radiographs of internal
undercut. This defect may be intermit-
tent or continuous (Figure 2) and either
on one side or both sides of the weld
centerline.

WHEN RADIOGRAPHS ARE INDICATIVE OF POOR WORKMANSHIP, BEST RESULTS CAN BE OBTAINED BY SHOWING THE
RADIOGRAPHS TO THE WELDER SO THAT HE CAN UNDERSTAND WHAT HE IS DOING WRONG AND CORRECT IT.

Figure 2. Radiographs of internal
undercut and the lack of penetration
which tends to occur at a stop and start.

Figure 3. Radiographs of lack of pen-
etration on the stringer bead appears
as a single, straight dark line.

Figure 4. Radiographs of unfilled
wagon tracks. Distinguishing between
this defect and internal undercut re-
quires skill and experience.