🎓 Engineering • Civil Engineering 100% Client-Side Privacy

Pipe Flow & Volumetric Discharge Calculator

Computes pipe discharge (L/s, m³/h, GPM) and friction head loss across pressurized conduits.

Pipe Hydraulics & Friction Loss

Volumetric Flow Rate & Head Loss

Solves fluid continuity Q = A · v, mass transfer rates, and Darcy-Weisbach friction head loss in circular conduits.

Standard Pipes:

Inner Dia D (mm)3.94 inches

Velocity v (m/s)6.6 ft/s

Pipe Length (m)164 ft

Darcy Friction fStandard: 0.015 - 0.03

Density (kg/m³)Water: 1000 kg/m³

Longitudinal Pipe Velocity Profile & Darcy Friction Loss

Volumetric Flow Rate (Discharge Q)

15.71 L/s

Equivalent to 56.55 m³/h | 249 US GPM (207.3 Imp GPM)

Darcy Head Loss (h_f)2.04 m6.69 ft of fluid head

Frictional Pressure Drop (ΔP)20 kPa2.9 psi (0.2 bar)

Hydraulic Power Required0.314 kW0.421 HP pumping energy

Governing Continuity & Energy Loss Equations

Cross Area A = π·D² / 4 = π·(0.1 m)² / 4 = 0.007854 m² (78.54 cm²)

Discharge Q = A · v = 0.007854 m² × 2 m/s = 15.71 L/s (56.55 m³/h or 249 US GPM)

Darcy-Weisbach h_f = f · (L/D) · (v²/2g) = 0.02 × (50/0.1) × (2² / 19.61) = 2.04 m head (20 kPa)

Pipe flow is the pressurized movement of fluids through enclosed conduits, governed by the continuity equation and friction head losses.

Q = A · v = (π · D² / 4) · v, h_f = f · (L / D) · (v² / 2g)

Continuity equation and Darcy-Weisbach friction head loss equation.

Example 1

Solution: Discharge Q = 15.71 L/s (56.55 m³/h, 249.0 GPM)

• Area = π × 0.1² / 4 = 0.007854 m²; Q = 0.007854 × 2 = 0.01571 m³/s = 15.71 L/s

Input inner diameter in mm.

Input speed in m/s.

Inspect discharge in L/s, m³/h, and US GPM.

Typically 1.0 to 2.5 m/s (3 to 8 ft/s) to prevent hydraulic erosion while avoiding excessive friction head loss.