Remaining life / Fitness-for-service
Tara Podnar McMahan
Head of Section
Integrity with confidence
A major consideration in appraising remaining life is pressure cycling and the effects of operational pressure cycle fatigue.
DNV GL conducts rainflow cycle counting to determine the effects of operational pressure cycling on defect growth. Unlike some rainflow counts that consider only points at suction and discharge, we calculate cycle counts throughout the length of the pipeline. Our work provides you with a critical assessment of flaws relative to their proximity to important integrity-affecting features such as pump stations with their respective elevations.
Our fatigue assessments take into consideration variations in pipe geometry, mechanical properties, hypothetical defect sizes, and pressure cycling to create a realistic fatigue growth simulation.
We have the software and the integrity subject matter experts (SMEs) to predict time-to-failure for a range of defect types. Pressure cycles, growth rate, material properties and fatigue are considered to arrive at defensible strategies for safer, trouble-free and compliant operations.