1. Stress Corrosion Cracking Overview & Introduction David Johnson December 2, 2003

2. 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

3. Requirements for SCC

4. SCC Characteristics

6. SCC near Seam Weld

7. Metallography of SCC

8. Summary of Incident Causes

9. 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

10. Why Today’s Interest? Other, higher significance threats also being addressed

11. Other Threats (B31.8S) External Corrosion Internal Corrosion Manufacturing Defects Welding & Fabrication Defects Equipment Failure Third Party / Mechanical Damage Incorrect Operations Weather & Outside Force

12. External & Internal Corrosion CP systems Gas quality standards and monitoring Relatively mature ILI capability Correlated to hydro-test capability Rapidly maturing DA capabilities

13. Manufacturing & Construction Specifications - materials & construction Advances in materials technology Mill inspections Construction inspections Proof testing

14. Third Party Damage Dig Safety Common Ground Alliance One Call enforcement Enhanced public awareness

15. Incorrect Operation Operator Qualification programs Qualification of controllers OQ-2 B31Q

16. Equipment Failure Gaskets, Seals, Valves, Pumps, etc. Generally not pipe Generally confined Specifications, testing, maintenance

17. Weather & Outside Forces Design & Construction Forecasting Monitoring Better understanding of material responses

18. 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

19. Today’s Workshop Share available information Understand application of current management techniques Update on R&D Future Needs –Technology development –Regulatory approach

20. 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

21. 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

22. Research & Development Multi-faceted approach Environmental factors Surface preparation & coatings CP system operation Operational factors Material behavior Detection & sizing

23. Regulatory Response Determining reasonable response Setting investigation protocols Communication needs

24. Upcoming Panels Operator Experience with Finding and Managing SCC 1.TransCanada 2.Enbridge 3.Kinder Morgan 4.Duke 5.Williams 6.Colonial

25. Upcoming Panels R & D –What’s been done –Current work –Future needs –PRCI –ILIA –NACE

26. Upcoming Panels Regulators –Concerns & Needs –NEB –EUB –MNOPS –USDOT-OPS

27. Dave.L.Johnson@Enron.com KLeewis@PRCI.org Contacts