Use flow, pressure and power data to find pumping inefficiency

Measure the operating point before changing equipment

A pump can be mechanically healthy and still use more energy than the system needs. Start by measuring flow, suction pressure, discharge pressure and electrical input under representative operating conditions. Compare the result with the pump curve and the intended duty point.

Repeat the measurements at different demand conditions. The objective is to understand the system curve, not merely capture one favourable reading.

Look for system causes of wasted energy

Common warning signs include continuous throttling, bypass flow, oversized pumps, high friction losses, parallel pumps operating outside their efficient range and fixed-speed operation where demand varies widely. Leakage and non-revenue water also carry a pumping and treatment energy penalty.

The South African Water Research Commission’s energy-efficiency compendium presents duty-point selection and variable-duty operation as important pump-efficiency considerations, with case studies showing that system changes can reduce energy use.

• Verify gauges, meters and current transformers before relying on the data.
• Compare actual and required flow rather than assuming nameplate duty.
• Inspect partially closed valves, bypasses and unnecessary static head.
• Assess controls and variable-speed options against the full demand profile.

Turn the baseline into a business case

Record energy per volume pumped where metering allows, then attach operating hours and tariff information. This creates a more credible comparison between control changes, hydraulic improvements, pump trimming, refurbishment and replacement.

Liquidflow can help define the measurements, verify the duty point and prepare a technically comparable equipment quotation. Any projected saving should be validated against the actual site profile and operating constraints.