Estimate the design flow needed for a leak collection pump or transfer system. The calculation combines the maximum observed leak flow with concurrent inflow, applies a peak multiplier, and adds a design margin. It also compares the required flow with a candidate pump rating to highlight available reserve or a capacity shortfall.
Required design flow is the minimum target at the stated assumptions. Pump selection must use the pump curve at the actual total dynamic head, not a nominal maximum-flow label.
This hydraulic screening estimate does not calculate head loss, suction conditions, solids handling, redundancy, or motor starting requirements.
A 35 gpm leak plus 15 gpm concurrent inflow gives 50 gpm. Applying a 1.25 peak multiplier and 20% margin produces a 75 gpm design requirement. An 80 gpm pump has 5 gpm of rated reserve at the design head.
A collection system must handle flows that can arrive at the same time, not the leak in isolation.
The peak factor represents expected flow variation; the margin provides extra design capacity for uncertainty.
Use the flow available at the system's actual total dynamic head, because pump flow changes with head.
The candidate pump rating is below the calculated design requirement by the displayed amount.
No. Pipe sizing also requires velocity limits, head loss, elevation, fittings, and material data.
| Stage | Calculation | Example |
|---|---|---|
| Base flow | Leak + concurrent | 50 gpm |
| Peak flow | Base × peak factor | 62.5 gpm |
| Design flow | Peak × 1.20 | 75 gpm |
| Capacity balance | Pump − requirement | 5 gpm |