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

RISK-BASED INSPECTION METHODOLOGY, PART 2—PROBABILITY OF FAILURE METHODOLOGY 2-59
8.10 Figures
H 2 S Content
of Water
STEP 1: Determine the environmental
severity using Table 8.2.
pH of Water
Brinell
Hardness
STEP 2: Determine the susceptibility for
cracking using Table 8.3.
PWHT?
Cracks
present?
Yes
High
Susceptibility
Cracks
Removed?
No
Yes
No
STEP 3: Determine the severity index from
Table 8.4.
FFS
STEP 4: Determine the time in-service,
age, since the last inspection.
STEP 5: Determine the number of inspections
and the corresponding inspection
effectiveness category for all past inspections
using Table 2.C.9.6.
STEP 6: Determine the base damage
factor for sulfide stress cracking using
Table 6.3.
STEP 7: Calculate the escalation in the
damage factor using Equation (2.27).
Figure 8.1—Determination of the SSC DF