Joint PRCI & DOT SCC Project Kick Off - Establishing Guidelines for the Identification of SCC Sites and the Estimation of Re-Inspection Intervals for SCCDA

In this PHMSA cofunded project, TransCanada Pipelines, Chevron and Gaz de France, the Pipeline Research Council International, Inc. (PRCI) will work with NOVA Research & Technology Centre to complement and build upon existing SCC DA procedures to better identify potential SCC sites for direct examination and to predict how frequently such inspections should be made.

The primary objective of this research is to develop a set of flexible, adaptable, non-prescriptive and quantitative guidelines for predicting where and when SCC might be an integrity threat for gas and liquid hydrocarbon pipelines. The guidelines will allow more-informed estimation of the re-inspection interval for repeat Direct Assessment (DA) procedures. These guidelines will be designed to:

• Complement other SCC methodologies, such as the NACE RP0204 [1], ASME B31.8S [10], and the CEPA Recommended Practices;
• Improve the industry’s ability to locate SCC in the field where the in-the-ditch protocols detailed in NACE RP0204 will be followed;
• Enable easy implementation, based on readily available inputs (size, grade, age, coating, etc.); operating data (temperature, pressure, CP, dents/gouges/stress raisers, etc.), and company-specific information (SCC data from previous excavations, ILI, operating history; terrain and landscape information, etc.), or in the absence of data, on generic values or estimates values developed through use of the guidelines;
• Assist operating companies to assess the level of risk, to develop and maintain a state-of-the-art integrity management plan, and to prioritize their maintenance activities in order to improve safety, and in making decisions about the frequency of re-inspection;
• Ensure broad applicability to a wide range of pipelines and operating conditions for liquid and gas pipelines, involving both the near-neutral and high-pH forms of cracking, all forms of coating and grades for both existing and new pipelines; and
• Provide predictions on both a local and regional scale permitting, for example, the identification of a particular site for excavation and also the prioritization of different lines for hydrotesting, in-line inspection, or DA.

The broad technical tasks involved in the study include: operating company data collection, analysis of this data, documentation of the effort and results, and technology transfer to industry.