Water Pump Repair
Case History #008 REV.04-97
LOCATION: Fresh water pumping station, California
This 14-foot diameter pump with a flow rate of approximately 280,000 gallons per minute began service in 1971. Erosion and cavitation rendered the pump inefficient. To put the efficiency rating back to original specifications, the owner bought and installed a new stainless steel pump impeller. After reassembly, pump efficiency still fell below the original specification. It was decided to rebuild the pump casing back to manufacturer’s specifications.
ARCOR™ S-30, ARCOR™ TSRB
Arcor provided material, plural spray component equipment and technical supervision to rebuild the pump casing. The entire pump casing, draft tube and discharge pipe were abrasive blasted to white metal with a 3-mil minimum profile. Arcor™ TS-RB was installed over the entire casing, building the eroded and cavitated regions proud of the surrounding substrate. After allowing this rebuild coat to set up hard, sanders were employed to create a smooth uninterrupted surface. Multiple coats of TS-RB were installed and sanded to bring the casing, draft tube and discharge pipe into specification.
With the rebuilding of the pump completed, two coats of Arcor™ S-30 were spray-applied. Forty mils of S-30 were applied to all areas with the exception of the leading edges of the stay vanes where a maximum of 8-10 mils were installed in order to meet original dimensions.
When this pump was originally installed, it had an efficiency rating of 91%. Test runs completed after it was rebuilt and coated with Arcor™ materials showed an efficiency rating of 91.5%. This project was completed in 1992 and is still functioning. Minor repairs have been made to the leading edges of the stay vanes where “vane fluting” caused the extra thin coating to erode.
Water pumping station.
Application of ARCOR TS-RB.
Top-coat of ARCOR S-30.