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Sanitary Sewer

Pipe sizing for gravity sanitary sewers using Manning’s equation, peak factor, and partial-flow ratios.

Inputs

Method
  • Q_avg = Pop·LPCD/86400 (L/s); Q_peak = Q_avg · PF.
  • Manning full pipe: Q_full = (1/n)·A·R^(2/3)·S^(0.5); A = πD²/4, R = D/4.
  • Compare Q_peak / Q_full → ratio → partial flow depth (lookup table).
  • Min velocity 0.6 m/s self-cleansing; max 3.0 m/s.

Results

Q_avg
Q_peak
Q_full
V_full
d/D ratio
Q/Qfull
Status