Understanding API ICP653 Reading 7-Worksheet-04 Part1

4.4.2 Causes of Bottom Leaks
Consider cause/effect/repair:
a. Internal pitting.
b. Corrosion of weld seams and HAZ
c. Weld joint cracking.
d. Stresses (roof support loads and settlement).
e. Underside corrosion (i.e., normally pitting).
f. Inadequate drainage.
g. Lack of an annular plate ring, when required.
h. Uneven settlement (with resultant high stress).
i. Roof support columns (or other supports) welded to bottom without
allowance for adequate movement.
j. Rock or gravel foundation pads.
k. Non-homogeneous fill under bottom (i.e., shell, rock, clay, wood stakes,
etc.).
l. Inadequately supported sumps.
Charlie Chong/ Fion Zhang