Understanding API ICP653 Reading 7-Worksheet-04 Part1

9.3.2 Lapped patch plates may be used to close holes.
9.3.2.1 The lap patch plate must be seal-welded, including the inner
perimeter of the hole. The minimum hole diameter is 2”.
9.3.2.2 Nozzle necks and reinforcing plates shall be entirely removed prior to
installation of a repair plate.
9.3.2.3 The overlap of a repair plate shall not exceed 8 times the shell
thickness, minimum overlap is 1”. The minimum repair plate dimension shall
be 4 inches.
9.3.2.4 The repair plate thickness shall not exceed the nominal thickness of
the shell plate adjacent to the repair.
1”min, 8t max
t patch ≤ ½” , >3/16”
t
D≥2”
Charlie Chong/ Fion Zhang