Maintenance shutdown planned

The Trans Alaska Pipeline System will be shut down for 26 hours on September 11 and 12 to replace a mainline Remote Gate Valve (RGV). The shutdown will begin at 7:00 a.m. Saturday. The pipe will be cut in two places to remove a section which includes the valve and 12 feet of pipe on either side. A new valve and pipe from Alyeska’s inventory will then be put into place and welded to the mainline.

To prepare for the shutdown, earlier this summer, two “hot taps” were made on either side of the valve to be replaced. Hot taps are made when a hole is drilled into the pipeline through a “split-tee” fitting. Oil continues to flow through the pipeline during this process. These hot taps will provide access ports into the pipe for equipment which will be used to isolate the RGV. After the hot taps were drilled, they were sealed and left in place. Earlier this week, the stopples were mounted on the split-tees in preparation for Saturday’s shutdown. A stopple is a sealing device that is inserted into the pipeline through the hot tap to stop the flow of oil. Once the valve is isolated, it will be cleaned and replaced.

The valve is located on the north bank of the Yukon River. In 1995, Alyeska began testing all of the 177 mainline valves on the pipeline. This RGV has an internal leak that does not allow a tight seal when the valve is closed. While this valve was well within the performance criteria established by Alyeska, it was determined the valve should be replaced due to the environmentally sensitive location of the valve.

During the shutdown, approximately 160 other work items will be completed at the pump stations, Valdez Marine Terminal and along the pipeline including valve testing, valve maintenance, instrumentation maintenance and other work that can’t be done while the pipeline is operating.

Media interested in touring the shutdown command center in Fairbanks during the shutdown should contact Tracy Green at 787-8679 to schedule a time. Video and still photos of the work site will be available to Alaska media shortly after the shutdown. For personnel and environmental safety, the work site will be restricted to project-related personnel only on the day of the shutdown.

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