Alyeska restarts pipeline after maintenance shutdown

by The Associated Press

Alyeska Pipeline Service Co. said Sept. 17 that the trans-Alaska oil pipeline was successfully restarted at 12:25 p.m. after a planned maintenance shutdown. The company said the shutdown lasted an hour and a half longer than the planned 27 hours because work crew experienced a delay when they had to re-weld a section of the pipeline after a major repair in North Pole.

The Joint Pipeline Office said that other than the re-weld at check valve 74, only a few minor glitches were reported and characterized the shutdown work observed by JPO staff as well planned and smoothly conducted.

The line was shut down at 7 a.m. Sept. 16 for 86 maintenance projects. Restart was scheduled for 11 a.m. Sept. 17.

The biggest project was the $5.8 million replacement of check valve 74 in North Pole. The check valve was damaged last July when a pig removed the seat ring from the valve. It was replaced with a check valve from Alyeska’s inventory. Once the damaged valve is inspected and repaired it will be returned to Alyeska inventory.

The M2 valve at pump station 9 in Delta was also isolated and removed during the shutdown, a job estimated at just under $1 million. Alyeska said that engineers determined the M2 valve was still operational at the time of its removal, but it did not perform to optimal standards and needed to be removed and examined before it eventually failed. The 48-inch ball valve is used to bypass the main line when a pig comes through the pump station.

In addition to the valve replacements, more than 80 other maintenance tasks were completed along the pipeline, at the pump stations and at the Valdez Marine Terminal.

Thirty-three mainline valves were tested during the shutdown to check internal sealing capabilities. Alyeska said it began a comprehensive valve-testing program in 1996 and has now tested nearly all of the 177 mainline valves on the pipeline. The three remaining untested valves will be examined Oct. 7 during a planned four to six hour shutdown to finish those checks.

Altogether, the work cost about $9 million.