Skip to main content

Find your next tool

DashboardAndroid app
Language
Appearance

Plant Engineering Calculator

Updated Sep 17, 2026

Pump Bypass Recirculation Loss Calculator

Quantify avoidable pump energy carried by bypass flow and annualize the cost opportunity.

Live calculationWorking shownPrivate in browser

Inputs

Results

Bypass hydraulic power 5.88 kW
Associated electrical input 8.53 kW
Annual wasted energy 51165.13 kWh
Annual cost $5116.51
More actions

Shared links reopen these inputs. Recent and saved calculations stay in this browser unless you clear site data.

Formula

Hydraulic power = ρgQH; electrical input = hydraulic power ÷ pump efficiency ÷ motor efficiency.

Your calculation, step by step

These steps use the values currently entered above so the result can be checked independently.

  1. 1.Formula: Hydraulic power = ρgQH; electrical input = hydraulic power ÷ pump efficiency ÷ motor efficiency.
  2. 2.Substitute: Bypass flow (L/s) = 20; Pump head (m) = 30; Density (kg/m³) = 1000; Pump efficiency (%) = 75; Motor efficiency (%) = 92; Hours/year = 6000; Energy price ($/kWh) = 0.10
  3. 3.Primary result: Bypass hydraulic power 5.88 kW

How to use this calculator

  1. Enter measured or design values using the units shown beside each field.
  2. Review the live results and the substituted calculation steps before using the estimate.
  3. Check the assumptions below, then continue to a related calculator when the next engineering decision needs another model.

Worked example

A 20 L/s bypass at 30 m head wastes about 5.88 kW hydraulically before pump and motor efficiency correction.

Assumptions and limits

  • Treats bypass flow and head as steady screening values.
  • Verify minimum-flow protection, pump curve and control requirements before reducing recirculation.

How to interpret the result

Treat the primary result as an engineering screening value, then use the secondary outputs to understand scale, energy or operating impact. Confirm site measurements, equipment limits and applicable standards before making a design or control change.

Questions engineers ask

When is bypass flow actually waste?

Only flow above the equipment or process minimum is a potential opportunity. Protective minimum-flow recirculation must not be removed without OEM and system review.

Why include both pump and motor efficiency?

Hydraulic power is lower than electrical input. Both efficiencies are needed to estimate the electrical energy associated with the bypass.

Continue the calculation

Use the next calculator in the same engineering workflow instead of restarting from search.

pump powerpump throttling losspump system curve
Methodology. MAXScanner shows the governing formula, entered values and calculation outputs so the estimate is auditable. The calculator is a screening aid; assumptions and equipment-specific limits remain part of the engineering review.