James Walker Group of the United Kingdom reports its HydroSele S shaft sealing system has completed two years of operation, running maintenance-free, at the 1,190-MW Entracque pumped-storage complex in Italy.
Walker said the HydroSele cartridge replaced a troublesome mechanical seal on Entracque’s Unit 9 that had to be changed frequently, resulting in a loss of generating capacity.
�We estimated that at this site, the HydroSele would pay for itself in less than two years, in terms of maintenance costs, turbine downtime, and power absorption,� Marco Nogarin, Walker’s senior representative in Italy said.
The Unit 9 125-MW turbine, originally supplied by Ansaldo of Italy, has a 680-millimeter-diameter shaft running at 600 rpm. It originally was fitted with a spring-energized conical wedge mechanical seal that leaked up to 300 liters per minute, causing plant flooding.
The HydroSele cartridge unit and adapter plate were installed by employees of project owner Enel in spring 2006 under Nogarin’s supervision. Since then, Walker said, the unit has worked, adjustment free with a carefully controlled leakage rate of only 15 liters per minute.
The Entracque pumped-storage complex includes the 1,065-MW Entracque-Chiotas plant and the 125-MW Entracque-Rovina plant on the Piastra River. Included in the same Piastra River power system is the 65-MW Andonno hydropower plant.