Overview


Challenges
  • High vibration and noise
  • Cavitation erosion on first-stage impeller
  • Impeller degradation
Results
  • Vibration reduced up to 75% (no contact value) and 80% (velocity value)
  • Hydraulic performance and NPSHr aligned with expected curves
  • Design point closer to operating points (81–105% Qdesign new versus 64–83% Qdesign old)
  • Reduced fluid dynamic forces
  • Increased reliability and reduced future maintenance costs
Case study details

A gas-sweeting plant in Malaysia had been using 10 of our 8x15 BF, two-stage BB1 amine pumps since 1996. For the last few years, the pumps had experienced recurring high vibration and impeller damage such as a cavitation erosion on inlet suction side, and disk break at impeller outlet.

Our operations profile analysis found a dominance of partial-load cases—especially high for energy-density pumps with high suction-specific speed—which explained the accumulation of cavitation and vibration damage.

After FMEA analysis, the customer agreed to our recommendation to redesign the impeller. CFD simulation and static structural profiles were performed with pressure load, and a model test bench was set up to compare new and old impeller designs—focusing on NPSHr curve and interacting forces between impeller blades and volute lip.

We replaced the six-blade impellers with a new seven-blade design, and the pumps are now operating without any vibration problems.

 

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