Qualifying a system according to DNV-RP-F118 typically involves several rigorous stages:

Are you using or a more specialized technique like TOFD ?

The primary goal of DNV-RP-F118 is to provide a consistent method for fulfilling the high-level requirements set by (the offshore submarine pipeline standard). It covers:

Comparing AUT results against "ground truth" data, often obtained through high-precision Immersion Ultrasonic Testing (IUT) or Destructive Testing (DT). Statistical Requirements