Challenge
After thirty years of service, the 54-inch circulating water pump impellers and rings at a coal-fired generating station were considerably worn and slated for replacement. A new impeller with full pump reassembly ran roughly $108,000 per pump — across twelve identical pumps, replacement was cost-prohibitive.
Belzona Solution
Instead of replacing, each worn impeller was built back to its original contour and size with pad welding, fitted with new impeller rings and remachined casing rings, then dynamically balanced. The balanced assembly was coated with Belzona molecular metal, which reduces friction across the vanes and waterways and extends impeller life. Leading edges were built up and reshaped, contours re-profiled against a release agent, and every surface sandblasted and degreased before application.
- Belzona molecular metal (Super Metal / R-Metal system)
Result
Rebuild cost about $19,500 per pump versus $108,000 for replacement — a total program saving of roughly $937,500 across all twelve pumps. Rebuilt pumps also drew an average of four fewer amperes per pump on the 4 kV bus, an auxiliary power saving of about 19.9 kW each. Inspections of rebuilt impellers have shown no measurable wear to date.
Project Photos
