Design a swirl separator that protects emitters well. Enter flow, pressure, and fitting sizes below. Get sizing checks, split ratios, and export reports instantly.
Tip: If you run multiple filters in parallel, enter total system flow and the number of units.
Use this example to validate your inputs and understand the output format.
| Scenario | Total Flow | ΔP | Inlet (mm) | Overflow (mm) | Underflow (mm) | Parallel Units |
|---|---|---|---|---|---|---|
| Medium garden drip system | 10.0 m³/h | 50 kPa | 50 | 60 | 20 | 1 |
| Two filters for larger zones | 20.0 m³/h | 60 kPa | 63 | 75 | 25 | 2 |
| Low headloss setup | 8.0 m³/h | 30 kPa | 50 | 60 | 20 | 1 |
This calculator uses a practical hydrocyclone-style approach for swirl separators:
Important: Empirical equations provide guidance, not a manufacturer guarantee. Always verify against the actual filter’s datasheet and installation limits.
A swirl (separator) filter uses a rotating flow to push heavier particles toward the wall and into the purge outlet. In gardens, it is commonly used ahead of drip lines to reduce sand loading, protect emitters, and cut maintenance. It works best on dense particles (sand/grit) and should be paired with a screen or disc filter for fine silt.
The two dominant sizing drivers are flow per unit and pressure drop across the separator. Higher flow increases inlet velocity, while higher pressure drop generally improves separation but raises energy cost. For practical planning, keep a safety factor (often 5–20%) to cover future zones and gradual fouling.
The calculator reports design flow per unit, inlet velocity, and an empirical capacity estimate. If the design flow exceeds the estimated capacity, consider a larger body, larger fittings, or two units in parallel. If inlet velocity exceeds your limit, the “required inlet diameter” highlights the fitting size needed to reduce velocity.
For a garden system at 10 m³/h with 50 kPa drop and a 10% safety factor, the design flow per unit becomes 11 m³/h. With a 50 mm inlet, the inlet velocity will typically fall in the mid‑m/s range. If your purge outlet is too small, the underflow may clog; if too large, separation weakens and purge losses rise.
No. It mainly removes heavier particles like sand. Fine silt and organic debris usually need a screen or disc filter downstream for reliable dripper protection.
Use the expected operating drop across the separator at normal flow. Avoid using pump shutoff pressure because it overstates performance and may mislead sizing.
When two or more separators share the total flow, each unit sees less flow and lower inlet velocity. This often improves separation and reduces headloss per unit.
Underflow is the purge stream that carries concentrated solids out of the separator. It is normally a small fraction of the total flow and is discharged during flushing.
Increase inlet diameter, reduce flow per unit, or add a second unit in parallel. Lowering inlet velocity improves hydraulic stability and reduces erosion in fittings.
No. Ratios are a starting point only. Always confirm final dimensions and rated capacity using the manufacturer’s datasheet for the exact model and operating range.
Start with a brief flush after installation and after dirty-water events. Then adjust to site conditions. If drippers clog or pressure rises, flush more frequently.
Important Note: All the Calculators listed in this site are for educational purpose only and we do not guarentee the accuracy of results. Please do consult with other sources as well.