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Pipeline & Facilities Integrity Management Remaining Life / Failure Avoidance / Asset Life Extension

DNV offers a dynamic blend of research science and engineering prowess. We help assure continuous delivery while extending the asset’s life and improving efficiency, safety and productivity. DNV is a single source provider of services that optimize the value of your pipeline throughout its entire life cycle.

Trusted globally since 1864


Remaining Life / Failure Avoidance / Asset Life Extension Operate with defensible, risk-informed decision making. Extend pipeline life. DNV has the software and the integrity subject matter experts (SME’s) to predict time to failure for a range of defect types. Pressure cycles, growth rate, material properties and fatigue are taken into account to arrive at defensible strategies for safer, trouble free and compliant operations. Two globally recognized experts in the field of fracture mechanics, Drs. John Beavers and Carl Jaske, lead a qualified staff of subject matter experts on all pertinent pipeline integrity disciplines. We have experts to deal with a range of integrity threats to include mechanical damage, cracks, corrosion, fatigue, and seamweld issues. We operate a comprehensive research science laboratory to augment our engineering strengths.

Rainflow Cycle Counting Helps Establish Remaining Life

Risk-Informed Decision Making Strain analysis

A major consideration in appraising remaining life is pressure cycling.

Corrosion, Cracking, Seamweld Defects

DNV conducts Rainflow Cycle Counting to determine the effects of operational pressure cycling on defect growth. Unlike other rainflow counts, we calculate the growth rate for a variety of defects at many discrete points down the length of the pipeline (not just suction and discharge) to provide you with a critical assessment of flaws relative to their proximity to pump stations and their elevation.

Predictive Modeling Failure Pressure Calculations Engineering Critical Assessments

Rainflow Cycle Counting is a means to predict future occurrence using historical data for SCC, seamweld issues and other fatigue susceptible threats.

Calculating Critical Flaw Size of Remaining Time-Dependent Defects Using initial flaw sizes provided by ILI, hydrotest, excavation, or statistical approximations, we’re able to manage large quantities of suspect anomalies based on historical data from known anomalies.

Equipment Testing 2000

Flow Reversal

1800 1600 1400

Pressure (psig)

Critical flaw dimensions and burst pressures can be calculated using DNV’s proprietary CorLAS™ fracture mechanics software which essentially outputs RSTRENG-like calculations for crack and corrosion defects.

1200 1000 800 600 400 200

Predicting failure pressure / remaining life from calculated critical flaw dimensions aids operators in establishing realistic and safe operating conditions, prioritizing remediation efforts and budgets, establishing re-assessment methodologies and intervals, and generally making better risk-informed decisions.

0 5/10/2006 0:00

5/11/2006 4:48

5/12/2006 9:36

5/13/2006 14:24

5/14/2006 19:12

5/16/2006 0:00

Date / Time

Shutdown Condition

Pipeline Pressure Data (Sample) (1 year of 5-minute readings desired)

Rainflow Cycle Count (Simplified) (ASTM E 1049-85)

Sound familiar? “Our hydrotest resulted in a test failure at the long seam. Can we determine a safe operating pressure over time for ‘just-surviving’ defects of similar nature?” “Repair, remediate, monitor. Can we arrive at a defensible position for deferring maintenance on defects that are borderline integrity threats?” “Management wants to know: What effect does a series of defects have on our ability to deliver product?” “I don’t know what to make of ILI data that seems to be going in all directions.”

DNV Energy North America US: Contact Chris.Pollard@DNV.com, ph. 281 396 1678 Canada: Contact Alasdair.Clyne@DNV.com, ph. 403 250 9041 ext. 241 www.DNV.com rev0910

Remaining Life_Failure Avoidance_Print 092710  

DNV offers a dynamic blend of research science and engineering prowess. We help assure continuous delivery while extending the asset’s life...

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