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Runner Diameter from Flow Split

Estimate an equivalent runner size when flow splits evenly across the number of paths entered.

Example starting values are prefilled to demonstrate the calculation. Replace them with your measured, quoted, or job-specific inputs before relying on a result.

Inputs

Inputs

Range: at least 0.0 in^3

Enter total volume flowing through the runner network during the fill interval.

Range: at least 0.0 s

Use the fill interval matching the entered volume; the model assumes a mean flow.

Range: at least 1

Enter a whole-number count; decimal values are rejected during calculation.

Range: at least 0.0 in/s

Enter a process/design velocity selected from material and mold knowledge. No universal recommendation is applied.

Result

Equivalent runner diameter (mm)
6.18
Mean flow per path (in^3/s)
0.1831
Equivalent runner diameter (in)
0.243
Equivalent runner area per path (in^2)
0.04650
Total network flow rate (in^3/s)
0.7323
Runner-design scope and limits
The result assumes equal flow division through the entered parallel paths and a circular runner section. Real runner systems require balance, pressure-drop, shear, cooling, weld-line, and mold-flow checks; the selected velocity is not a universal recommendation.

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