# Presentation: 423817

## 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

## Requirements for SCC

## SCC Characteristics

## SCC Characteristics

## SCC near Seam Weld

## Metallography of SCC

## Summary of Incident Causes

## 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

## Dave.L.Johnson@Enron.com 

- KLeewis@PRCI.org

- Contacts