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

PART 1—INTRODUCTION TO RISK-BASED INSPECTION METHODOLOGY 1-27
Table 4.2—Numerical Values Associated with POF and Financial-based COF Categories
a, b, c
Probability Category Consequence
Category d
Category
Probability Range DF Range Category Range ($)
1 P f (t,I E ) ≤ 3.06E-05 D f-total ≤ 1 A
fin
CA ≤ 10,000
f
fin
2 3.06E-05 < P f (t,I E ) ≤ 3.06E-04 1 < D f-total ≤ 10 B 10,000 < CA ≤ 100,000
fin
3 3.06E-04 < P f (t,I E ) ≤ 3.06E-03 10 < D f-total ≤ 100 C 100,000 < CA ≤ 1,000,000
fin
4 3.06E-03 < P f (t,I E ) ≤ 3.06E-02 100 < D f-total ≤ 1000 D 1,000,000 < CA ≤ 10,000,000
f
f
f
5 P f (t,I E ) > 3.06E-02 D f-total > 1000 E
fin
CA > 10,000,000
f
a
POF values are based on a gff of 3.06E-05 and an FMS of 1.0. If the suggested gff values of Part 2, Table 3.1 are used, the
probability range does not apply to AST shell course, AST bottoms and centrifugal compressors.
b
In terms of POF, see Part 1, Section 4.1.
c
In terms of the total DF, see Part 2, Section 3.4.2.
d
In terms of consequence area, see Part 3, Section 4.12.1.
4.7 Figures
Total Risk
Risk
Risk for Damage 1
A+B+C=Total Risk
Risk for Damage 2
A
B
C
Risk for Damage 3
Installation
Date
Figure 4.1—Superposition Principle for the Calculation of Risk
t
time