Sewer Pipe Sizing (MSIG/SPAN)

Ref: MSIG (Malaysian Sewerage Industry Guidelines) & SPAN UTG

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Q_design = PF × DWF + Infiltration

Ref: MSIG (Malaysian Sewerage Industry Guidelines) & SPAN UTG

DWF = PE × q / 86400 (L/s)

Dry Weather Flow

PF = 1 + 14 / (4 + √(PE/1000))

Harmon's Peak Factor

Q_full = (1/n) × A × R^(2/3) × S^(1/2)

Manning's full flow

Sewage Flow

Population Equivalent (PE)

Total PE served (residential: 1 PE per person)

Per Capita Sewage Flow (L/person/day)

MSIG standard: 225 L/person/day (domestic)

Infiltration Allowance (L/s)

Typical 0.05 L/s per mm dia per km of sewer

Pipe Properties

Pipe Diameter (mm)

Min 150mm (house), 200mm (public sewer)

Pipe Slope (m/m)

Min 1:200 for 150mm, 1:250 for 200mm

Manning Roughness (n)

uPVC/VC 0.011, Concrete 0.013

Disclaimer: This output is an engineering calculation aid only and does not constitute a final or endorsed design. All designs submitted to Malaysian authorities must be endorsed by a registered Professional Engineer (PE) under the Board of Engineers Malaysia (BEM) in accordance with the Registration of Engineers Act 1967.