In the Field

VMT crews overhaul Power/Vapor's C Turbine

On average it takes seven to eight megawatts of power to keep up with the electrical demands of the Valdez Marine Terminal. So how does Alyeska generate seven to eight megawatts of electricity? “With our steam turbine/generators,” said John Fannin, Alyeska’s Power Vapor Manager.

The VMT generates electrical power with three steam turbine/generator (TG) units. Recently, one of these TGs (C Turbine) was taken down for a complete overhaul after it experienced a bearing failure. This overhaul included disassembling the TG, cleaning and inspecting all of its internal parts, conducting extensive inspections and tests on these components, replacing and/or repairing key pieces as necessary, and then, finally, putting all of the TG’s components back together.

“This is no small task when you consider the TG is made up of several hundred pieces and parts that each weigh anywhere from 10 pounds to 10 tons, and each must be put together with tolerances as close as one-half of one-thousandth of an inch,” said Mike Drew, VMT Mechanical Maintenance Supervisor. That’s like taking a 10-ton piece of metal—a 20,000 pound piece of machinery—and spinning it like a top on a precise axis that must not vary more than half the thickness of a single piece of paper.

This $2 million project was managed by VMT Maintenance Personnel and completed by Dresser-Rand Millwrights with the assistance and support from baseline contract labors, Superior Electric and APSC Engineering. In all, the project took approximately eight months to complete.

“I would like to thank the crews for completing the project with an exceptional focus on safety. Everyone knew the goals for each day, what individual tasks needed to be completed to achieve the goals, the hazards involved with each task and the protective measures that needed to be followed to deliver on safety. Communication was great.” Fannin said.

The complete overhaul of the C Turbine ensures that Power/Vapor will continue to support Terminal operations with the high degree of reliability we have grown to expect from TAPS.