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Stress Corrosion Cracking Overview & Introduction. David Johnson December 2, 2003. SCC History. Not a recent phenomenon Not exclusive to pipelines Not confined to underground environment Not geographically limited Ammonia cracking of cartridge brass Chloride cracking of stainless steel.
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Stress Corrosion CrackingOverview & Introduction David Johnson December 2, 2003
SCC History • Not a recent phenomenon • Not exclusive to pipelines • Not confined to underground environment • Not geographically limited • Ammonia cracking of cartridge brass • Chloride cracking of stainless steel
Summary of Significance • Natural gas transmission(1985-2002) • 15 of 1415 total reported incidents • Liquid transmission (PPTS) • 5 of 472 in database • NEB (Canada) (1992-2002) • 3 of 23 • None since 1995 • Overall - about 1% of incidents
Why Today’s Interest? • Other, higher significance threats also being addressed
Other Threats (B31.8S) • External Corrosion • Internal Corrosion • Manufacturing Defects • Welding & Fabrication Defects • Equipment Failure • Third Party / Mechanical Damage • Incorrect Operations • Weather & Outside Force
External & Internal Corrosion • CP systems • Gas quality standards and monitoring • Relatively mature ILI capability • Correlated to hydro-test capability • Rapidly maturing DA capabilities
Manufacturing & Construction • Specifications - materials & construction • Advances in materials technology • Mill inspections • Construction inspections • Proof testing
Third Party Damage • Dig Safety • Common Ground Alliance • One Call enforcement • Enhanced public awareness
Incorrect Operation • Operator Qualification programs • Qualification of controllers • OQ-2 • B31Q
Equipment Failure • Gaskets, Seals, Valves, Pumps, etc. • Generally not pipe • Generally confined • Specifications, testing, maintenance
Weather & Outside Forces • Design & Construction • Forecasting • Monitoring • Better understanding of material responses
Why Today’s Interest? • Other, higher significance threats also being addressed • Less apparent understanding • Small, but widespread, occurrence • Methods of addressing not as mature • Inspection, characterization, assessment, management
Today’s Workshop • Share available information • Understand application of current management techniques • Update on R&D • Future Needs • Technology development • Regulatory approach
Managing SCC • Operators have found & managed SCC • Tools as prescribed in PLSIA of 2002 • In-Line Inspection • Hydrostatic Testing • Direct Assessment • Other • All have specific capabilities & limitations • Gas - Liquid Pipeline Differences
Major Challenges • Finding SCC • Shallow cracks initially • May not be visible to unaided eye • Gas - Liquid technology differences • Service disruptions • Water disposal • Assessing what is found • Mitigation and Management
Research & Development • Multi-faceted approach • Environmental factors • Surface preparation & coatings • CP system operation • Operational factors • Material behavior • Detection & sizing
Regulatory Response • Determining reasonable response • Setting investigation protocols • Communication needs
Upcoming Panels • Operator Experience with Finding and Managing SCC • TransCanada • Enbridge • Kinder Morgan • Duke • Williams • Colonial
Upcoming Panels • R & D • What’s been done • Current work • Future needs • PRCI • ILIA • NACE
Upcoming Panels • Regulators • Concerns & Needs • NEB • EUB • MNOPS • USDOT-OPS
Contacts Dave.L.Johnson@Enron.com KLeewis@PRCI.org