Successful Modification Of Vertical-Turbine Pumps For Capacity And Reliability Improvement
Abstract
A modification of seven 560 hp vertical-turbine pumps was carried out with outstanding
results to improve their actual capacity. The installation was limited to 64% of its rated
capacity, which was never reached, and the operating demand required to maintain all
seven pumps in continuous service. Reliability of the pumps was additionally impaired by
severe cavitation damage of impellers.
A plant revamp required increased and reliable cooling water flow, with a limited time
frame of seven months for full implementation. Original cast iron impellers were reverse
engineered and manufactured oversize in 18Cr-16Mn steel. Bowls were modified for the
larger impellers. Performance for all pumps was adjusted in a test stand and the efficiency
improved not to exceed the rated horsepower of installed electric motors.
As a result, the capacity of the installation reached its rated value. Operation was
optimized with six pumps in operation and one in standby feeding 33% more water. After
26 months in service, none of the pumps had shown capacity drop or required
maintenance beyond repacking. Significant savings were attained compared to the
installation of new pumps.
Description
Case StudySubject
Pumping machineryCollections
Citation
Morales Casanova, César A. (2000). Successful Modification Of Vertical-Turbine Pumps For Capacity And Reliability Improvement. Texas A&M University. Turbomachinery Laboratories. Available electronically from https : / /hdl .handle .net /1969 .1 /164077.