PG&E crews will be welding a section of a natural gas pipeline in Palo Alto Friday, tying the line back into the statewide transmission system, according to Palo Alto Utilities Communications
Manager Debra Katz.
After the welding is completed on the T-30 section of Line 132, the line will be purged, releasing gas into the air in San Carlos but not in Palo Alto, Katz wrote in an email Thursday.
Friday morning PG&E crews vented gas from a small portion of the T-30 segment the intersection of Alma Street and Oregon Expressway "to create safe conditions for welding the small section to the main section," Katz stated.
PG&E expects to return the pipeline to full service by Saturday (Nov. 19), Katz stated.
Crews had been performing hydrostatic pressure tests -- in which the pipeline is cleared of gas and filled with water to detect weaknesses -- on a portion of Line 132 between Sand Hill Road and Page Mill Road, when a pin-sized leak measuring 1 or 2 millimeters was located near Hanover Street in Palo Alto on Nov. 3, PG&E spokesman Brian Swanson said. Repairs were completed Nov. 9, he said.
Crews resumed hydrostatic testing Nov. 10 to determine if there were any more weaknesses on the portion of pipeline. On Nov. 6, pressure testing on a 3-mile portion of Line 132 near Woodside caused a rupture that sent water from inside the pipe down a hillside above Interstate Highway 280.
Mud and water blocked two lanes of the highway for more than two hours. PG&E investigators determined that the pipe had been damaged by construction equipment, Swanson said.
A faulty seam on Line 132 ruptured in San Bruno on Sept. 9, 2010, causing an explosion that killed eight people and destroyed 38 homes.
For more information, visit www.cityofpaloalto.org.