Pipeline back up after maintenance

Petroleum News Alaska Staff

The trans-Alaska pipeline was shut down Sept. 22 for scheduled maintenance and restarted Sept. 23. Some 60 maintenance tasks were done on the pipeline and in the pump stations, including maintenance on several of the mainline valves.

Piping tie-ins were installed at Pump Station 5 to allow future connection of equipment to assist in the unlikely event of a cold pipeline restart.

Other work included servicing of many station valves and fittings, performance of regulatory required checks of systems and valves and additional operator training for abnormal operating conditions.

It was longer than the anticipated 12 hours from shutdown to startup because of several unexpected events during restart. Some 200 gallons of crude spilled onto the pump room floor at Pump Station 4 after escaping through a grease fitting on a suction valve.

A relief valve released crude at Pump Station 5 during the startup. Alyeska said an open block valve caused the relief valve to activate, releasing crude onto the floor in an enclosed manifold building.

A main pump seal failed and released about 80 gallons of crude into the pump room at Pump Station 3 during restart. The cause of the seal failure is under investigation.

All crude releases were cleaned up before the pipeline was restarted at approximately 4 a.m. Sept. 23.