API RP 581 - 3rd Ed.2016 - Add.2-2020 - Risk-Based Inspection Methodology

2-54 API RECOMMENDED PRACTICE 581
7.10 Figures
STEP 1: Determine the susceptibility
for cracking.
Cracks
present?
Yes
High
Susceptibility
Cracks
Removed?
Yes
Exposed to lean
Amine?
No
No
Stress
relieved?
Yes
Not
Susceptible
Yes
No
No
FFS
Not
Susceptible
Exposed to
MEA or DIPA?
No
Exposed
to DEA
No
Yes
Yes
Temp >
180°F?
Yes
High
Susceptibility
Temp >
180°F
Yes
Medium
Susceptibility
No
No
Temp
100 –
180°F?
Yes
Temp
140 -
180°F?
Yes
Yes
Temp >
180°F?
No
No
No
Heat
Traced?
Yes
Heat
Traced?
Yes
Yes
Heat
Traced?
No
No
No
Steamed
Out?
Yes
Steamed
Out?
Yes
Yes
Steamed
Out?
No
Low
Susceptibility
Medium
Susceptibility
No
Not
Susceptible
Low
Susceptibility
No
Not
Susceptible
STEP 2: Determine the severity index
from Tabl .7.2.
STEP 3: Determine the time in-service,
age, since the last inspection.
STEP 4: Determine the number of inspections
and the corresponding inspection
effectiveness category for all past inspections
using Table 2.C.9.1.
STEP 5: Determine the base damage
factor for amine cracking using Table
6.3.
STEP 6: Calculate the escalation in the
damage factor using Equation (2.26).
Figure 7.1—Determination of the Amine Cracking DF