Pipe Flow Engineering Hub

Pipe Flow Calculator Hub

Complete pipe flow engineering calculations — flow rate, velocity, pressure drop, Reynolds number, friction loss and pump sizing. Based on Darcy-Weisbach and continuity equations.

Core Pipe Flow Formulas

Q = A x v

Continuity equation: Flow rate = Area x Velocity

Re = rho x v x D / mu

Reynolds number: Laminar (Re<2300) vs Turbulent (Re>4000)

hf = f x (L/D) x v^2/(2g)

Darcy-Weisbach: Major friction head loss

dp = f x (L/D) x (rho x v^2)/2

Pressure drop from friction

v = Q / A = 4Q / (pi x D^2)

Velocity from flow rate and diameter

Pipe Flow Calculators

Pipe Flow Calculator

Calculate volumetric flow rate in a pipe from pipe diameter and fluid velocity using Q = A × v.

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Flow Rate Calculator

Calculate volumetric flow rate from pipe diameter and velocity, with unit conversions.

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Pipe Velocity Calculator

Calculate fluid velocity in a pipe from flow rate and pipe diameter.

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Pipe Diameter Calculator

Calculate required pipe diameter from flow rate and target velocity.

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Pressure Drop Calculator (Darcy-Weisbach)

Calculate pressure drop in a pipe using the Darcy-Weisbach equation: ΔP = f × L/D × ρv²/2.

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Friction Loss Calculator

Calculate friction head loss in pipes per 100m using Hazen-Williams C-factor for water systems.

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Head Loss Calculator

Convert pressure drop to head loss in meters or feet of fluid column for pump sizing.

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Reynolds Number Calculator

Calculate Reynolds number to determine flow regime (laminar, transitional, turbulent) in pipes.

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Darcy-Weisbach Pressure Drop Calculator

Calculate pressure drop in pipes using the Darcy-Weisbach equation with full parameter control.

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Orifice Plate Flow Calculator

Calculate flow rate through an orifice plate using ISO 5167 differential pressure method.

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Pipe Volume Calculator

Calculate pipe internal volume and liquid capacity for filling, flushing, and hydrotesting.

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Hydraulic Diameter Calculator

Calculate hydraulic diameter for non-circular ducts and pipes used in Reynolds number and pressure drop.

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Flow Regime Classification

Reynolds NumberFlow RegimeCharacteristics
Re < 2300LaminarSmooth parallel streamlines, parabolic velocity profile, f = 64/Re
2300 ≤ Re ≤ 4000TransitionalUnstable flow, intermittent turbulence, use safety factor
Re > 4000TurbulentChaotic mixing, flat velocity profile, use Colebrook or Swamee-Jain for f

Related References