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

RISK-BASED INSPECTION METHODOLOGY, PART 2—PROBABILITY OF FAILURE METHODOLOGY 2-131
19.8 Tables
Table 19.1—Data Required for Determination of Susceptibility to HTHA
Required Data
Material of construction
Hydrogen partial pressure, MPa (psia)
Temperature, °C (°F)
Comments
The component generic construction material (e.g. carbon steel, C-½ Mo,
2 ¼ Cr-1 Mo).
Determine the hydrogen partial pressure, which is equal to the product of
the mole fraction of hydrogen and the total pressure (absolute).
The temperature of exposure.
Table 19.2—DF—HTHA
Susceptibility
DF
Damage Observed 5000
High Susceptibility 5000
Medium Susceptibility 2000
Low Susceptibility 100
No Susceptibility 0