Minimum Required Wall Thickness

To Meet API-579 Part 5 Level 1 LTA FFS Criterion

1. Pressure = MAWP
2. Samples taken in the longitudinal direction.
3. LTA away from structural discontinuities.
4. No corrosion allowance (CA) considered. Add required CA to minimum thickness.
5. Assumes pressure minimum thickness (tmin) remote from LTA.
6. RSFa = 0.9.
7. Basemetal is defined as max[t, 1.0 in.] removed from the center of a weld.
8. JE = Joint Efficiency
9. Screening curves assumed the shells are not subject to cyclic service or operating at temperature within the creep range.