Extraits de Enbridge responses to NEB Information request no 2 to Condition 9 :
The criteria for corrosion feature excavation selection include all features with a depth of ≥50% of wall thickness (“WT”) or a rupture pressure ratio (“RPR”) of ≤1.0. [...] Enbridge defines RPR as the predicted failure pressure (“Pf”) divided by pressure at stress of 100% SMYS..." (p.3).
For ILI activities related to crack features, Enbridge uses a safety factor (Pf/MOP) approach..." (p.7).
Enbridge can confirm that the four features discussed in the preamble, and all features on Line 9 with a safety factor less than 1.25 have been repaired" (p.9).