Case Study: Dinorwig Power Station
Specialist bespoke machining solution for largest pumped storage power station
CUSTOMER: First Hydro Dinorwig Power Station North Wales
To repair a 5.5 metre diameter pump-turbine regulating ring bearing and top cover journal face, in-situ, in one of Europe’s largest pumped storage power stations while avoiding the need for a several week shutdown and lost generating time.
The bespoke circular self-levelling milling machine was developed and operated by specialty services company Furmanite for Dinorwig power station in North Wales, operated by First Hydro company and owned by Edison Mission Energy, to repair a damaged bearing track and to replace the grease lubricated bronze with a self lubricating bearing. First Hydro Company was keen to move away from grease for environmental reasons and to improve working conditions.
The phosphor bronze regulating ring bearing was found to be worn, and there was damage caused to the top cover vertical and horizontal journal faces by the bearing’s retainer screws having worked loose. The damage had to be repaired before replacing the bearing, but stripping down the turbine and removing the top cover (5.5 metres diameter, weighing 100 tons) to a workshop, would have entailed several weeks’ shutdown, and transportation of the sizeable cover.