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Inspection Trends - April 2011 - Spring

PG&E Proposes Plan for Field Testing and Inspecting of Key Pipelines Girth Weld Girth Weld Girth Weld Girth Weld Girth Weld North End Direction of gas flow South end Short Segments: 1-4 Pacific Gas and Electric Co. (PG&E) recently submitted records to the California Public Utilities Commission for pressure tests or historical operating pressure on more than 90% of its 1805 miles of natural gas transmission pipelines in high-consequence areas. The utility also presented an inspection and field test plan. The actions are a result of the September 9, 2010, natural gas pipeline rupture and explosion that killed eight people in San Bruno, Calif. The inspection and field test plan includes in-line inspection with “smart pigs” and new camera inspection technologies. It also plans to hydrostatically pressure test or replace 150 miles of pipeline with records similar in vintage or other characteristics of that for the segment involved in the San Bruno incident. The records were submitted in response to the commission’s order to provide “traceable, verifiable, and complete” records that establish each pipeline’s maximum allowable operating pressure (MAOP). While current regulations permit operators to establish MAOP for pre-1970 pipelines based on historical operating pressures, in its filing, PG&E said it supports steps to “raise the bar” on current standards industry-wide through “a thoughtful review and enhancement of existing safety standards, including phasing out the use of historic operating pressure to establish MAOP of pipelines.” 8 Inspection Trends / April 2011 News Bulletins A 28-ft-long ruptured section of the San Bruno pipeline at the laboratory facilities at the NTSB Training Center, Ashburn, Va.


Inspection Trends - April 2011 - Spring
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