Pump, Compressor & Rotating Equipment Assembly worked example

Impeller Trim Effect at 99% line efficiency: a worked example

What does the result look like when line efficiency reaches 99%? The full calculation is worked below with real intermediate numbers. Use it when impeller trim effect in pump, compressor and rotating equipment assembly is being committed and you need a throughput number you can defend.

The inputs for this scenario

  • Units completed in the period: 1,200 units (unchanged)
  • Assembly runtime: 8 hr (unchanged)
  • Line efficiency: 99 % (raised for this scenario; the documented default is 90)

Working through the calculation

  • Applying the documented formula (Raw impeller trim effect = completed output รท runtime) to the inputs above produces each figure below.
  • At this operating point the engine returns 149 units for effective throughput, the number this scenario is built around.
  • At this operating point the engine returns 150 units for raw throughput.
  • At this operating point the engine returns 99 % for efficiency.
  • At this operating point the engine returns 8 hr for runtime.

How this compares with the baseline

  • Against the tool's baseline example, where line efficiency sits at 90% and the headline result is 135 units, this scenario comes in 10% above the baseline at 149 units.
  • A figure at this level is achievable when line efficiency is genuinely sustained, not just peaked for a shift. A single efficiency factor lumps together downtime, speed loss, and rework; it won't tell you which of those is dragging the effective rate down.

Results at a glance

  • Effective throughput: 149 units (headline result)
  • Raw throughput: 150 units
  • Efficiency: 99 %
  • Runtime: 8 hr

Run it with your numbers

  • Every input above is editable in the live Impeller Trim Effect calculator, which recalculates instantly and can be shared with the inputs intact.

Last reviewed 2026-05-12.