Equalization Tank Sizing & Transfer Pumping Calculator

Screen preliminary equalization storage using a transparent cumulative volume balance. The calculator represents one peak-flow block within a daily cycle, calculates storage above the selected equalized discharge rate, adds a design allowance, and screens the transfer pump and its energy demand.

Use measured hourly data for final design. This two-block pattern is a preliminary representation only. For a project design, replace it with the complete 24-hour (or shorter-interval) influent profile and verify mixing, solids settling, odour control, standby, high-level storage, and pump controls.

Equalization and transfer inputs Define daily flow, a representative peak block, and the transfer-pumping screen.

Daily flow and equalized discharge

Average Daily Influent Volume

m³/day

Equalized Discharge Window

hours/day transfer to treatment

Peak Inflow Duration

hours/day in the peak block

Peak Inflow Factor

peak inflow ÷ 24-hour average inflow

Storage Allowance

percent above calculated balancing storage

Operating Days

days/year

Transfer pump screening

Transfer Pump Total Head

mH₂O; use Hydraulic Profile tool for detailed line screen

Overall Electrical-to-Liquid Efficiency

percent; pump × motor × drive

Storage, flow-balancing, and transfer results The peak block fills the equalization volume; the remaining period releases it under the equalized flow.

Governing mass balance

Equalization storage is obtained from the cumulative difference between inflow and the selected equalized outflow. The calculator represents a peak block followed by a base-flow block that preserves the user-entered daily volume.

Q_equalized = Daily volume ÷ discharge window

Q_peak = (Daily volume ÷ 24) × peak-flow factor

ΔV = (Q_in − Q_equalized) × Δt

V_gross = max(cumulative ΔV) − min(cumulative ΔV)

V_design = V_gross × (1 + allowance)

Transfer-pump electrical power is screened from the equalized flow and total head: P = ρgQH ÷ η. The annual energy uses the selected equalized discharge window and operating days.

Design limitations

The calculator does not establish emergency storage, freeboard, high-level alarm volume, residual process volume, mixing equipment, aeration, cleaning, or odour-control requirements. The selected storage allowance is not a substitute for these independent volumes.