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Plant Engineering Calculator

Pump Throttling Loss Calculator — Valve Head, Wasted kW & VFD Opportunity

Quantify hydraulic power dissipated across a throttling valve from flow and excess head, estimate electrical input associated with that loss, and annualize the energy-cost opportunity.

Inputs

Results

Hydraulic throttling loss 9.81 kW
Associated electrical input 14.21 kW
Annual energy opportunity 85275 kWh
Annual cost opportunity $8528

Formula

Phyd=ρgQΔH; Pelec=Phyd/(ηpump×ηmotor).

Worked example

At 50 L/s and 20 m excess valve head, water loses about 9.8 kW hydraulically before pump and motor efficiency are considered.

Assumptions & limits

  • This isolates excess throttling head; a VFD retrofit must be checked against the full system and pump curves.
  • Minimum speed, static head, control authority, motor cooling and process constraints can limit savings.

FAQs

What does this Pump Throttling Loss Calculator calculate?

Quantify hydraulic power dissipated across a throttling valve from flow and excess head, estimate electrical input associated with that loss, and annualize the energy-cost opportunity.

Can I use the result for final equipment selection?

Use it as a transparent engineering and energy-screening result. Verify final decisions with measured site data, OEM curves, applicable standards and operating limits.

Why does MAXScanner show assumptions?

Plant calculations can look exact while depending heavily on operating assumptions. Showing them makes scenarios auditable and easier to compare.

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Last updated: 17 September 2026