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

RISK-BASED INSPECTION METHODOLOGY, PART 2—PROBABILITY OF FAILURE METHODOLOGY 2-87
13.9 Tables
Table 13.1—Data Required for Determination of the DF—HSC-HF
Required Data
Susceptibility (Low, Medium, High)
Presence of HF (Yes or No)
Brinnell hardness of steel weldments
Age (years)
Inspection effectiveness category
Number of inspections
Comments
The susceptibility is determined by expert advice or using the procedures in this
section.
Determine whether HF may be present in the component. Consider not only
normal operating conditions but also upset conditions that may allow carryover
of HF from other components.
Determine the maximum Brinnell hardness actually measured at the weldments
of the steel component. Readings should be made and reported using Brinnell
scale, not converted from micro-hardness techniques (e.g. Vicker, Knoop, etc.).
If actual readings are not available, use the maximum allowable hardness
permitted by the fabrication specification.
Use inspection history to determine the time since the last SCC inspection.
The effectiveness category that has been performed on the component.
The number of inspections in each effectiveness category that have been
performed.
Table 13.2—Susceptibility to Cracking—HSC-HF
As-welded
Max Brinnell Hardness
PWHT
Max Brinnell Hardness
<200 200 to 237 >237 <200 200 to 237 >237
Low Medium High None Low High
Table 13.3—Determination of Severity Index—HSC-HF
Susceptibility
Severity Index—S VI
High 100
Medium 10
Low 1
None 0