Understanding API ICP653 Reading 7-Worksheet-04 Part1

5.2.1 Reported conditions involving failures (primarily involving welded tanks):
a. Hydro test at initial erection.
b. First filling in cold weather.
c. After a change to lower temperature service.
d. After a repair-alteration.
5.2.2 Any change in service must be evaluated to determine if it increases the
risk of failure due to brittle fracture. For example, the change to a more
severe service involving one of the following:
a. Lower operating temperature (especially below 60°F).
b. Product with a higher specific gravity.
* Consider need for hydrostatic test when any repair or alteration does not
meet all requirements of the 653 standard or deterioration of the tank has
occurred since the original hydrostatic test.
Charlie Chong/ Fion Zhang