Hydroelectric Component Rehabilitation Services
As the nation’s complement of hydroelectric stations rapidly ages, they remain an important and integral part of our current ability to meet the energy needs of the country. We are able to help with virtually all aspects of the rehabilitation of these units. Where feasible, it is generally much more cost efficient to rework components in our shop. But, if not, we are ready and willing to perform whatever machining services that you need at your site. To the right you see a head cover that has been reworked and is being prepared for loading. All items of this type are first blasted to near white metal and then they receive several applications of a coating recommended for this service. Except for machined fits, which receive a single application of a rust inhibitive primer.
Once the components have been replaced and realigned in the dam, a portable boring machine is carefully aligned with the wicket gate bearing bores and plumb. This not only assures free movement but also proper seal.
Once the line boring has been completed, new bearings are manufactured and installed. Grub screws are added around the periphery of the bearing flange to insure that it remains static.
Lower guide bearings are blasted to “near white” metal and any cavities found are filled. They then receive multiple applications of a coating suitable for their service. Case halves are carefully aligned and doweled. The bronze on locating surfaces is replaced and re-machined to insure proper fit in it’s housing. The bearing surface itself can either be relined with a conventional material such
as the Thordon™ shown above or with a traditional material such as Lignum Vitae. In short, all locating surfaces of the bearing are re-machined to ensure proper size, concentricity to one another and, in the case of flanges, perpendicularity to centerline.
The seal ring is also relined and placed on top of the guide bearing. Once it has been aligned concentrically with bearing bore, it is doweled in place. This is to ensure the best possible result at assembly while requiring the least amount of time spent by the assemblers aligning components to one another.
A relined packing flange that is ready for assembly.
Turbine shafts have their wear sleeves (if any) removed. The shaft is then placed in a lathe where the sleeve area may be checked for “runout” and trued if necessary. New sleeves are then installed and machined to size. Mating flanges on either end of the turbine shaft are checked and re-machined if necessary to ensure perpendicularity to the centerline of rotation.