Example (General Metal Loss – Part 4): For a cylinder with corrosion thinning, the remaining thickness ratio is: ( R_t = \fract_mm - FCAt_nom - FCA ) (where FCA = Future Corrosion Allowance). Then the RSF is derived from the flaw dimensions and shell geometry.
The standard utilizes a three-level approach to balance conservative safety margins with engineering effort: api 579 ffs
For crack-like flaws (Part 6), the FAD is the universal tool. It plots two axes: Example (General Metal Loss – Part 4): For