Understanding API ICP653 Reading 7-Worksheet-04 Part1

3.23 major alteration or major repair:
An alteration or repair that includes any of the following:
a. Installing a shell penetration larger than NPS 12 beneath the design liquid
level.
b. Installing a bottom penetration within 12 in. of the shell.
c. Removing and replacing or adding a shell plate beneath the design liquid
level.
d. Removing or replacing annular plate ring material where the longest
dimension of the replacement plate exceeds 12 in.
e. Complete or partial (more than one-half of the weld thickness) removal
and replacement of more than 12 in. of vertical weld joining shell plates or
radial weld joining the annular plate ring.
Charlie Chong/ Fion Zhang