FT-05 · Internal flow

Pipes in series

Solves for the same flow rate through segments of different geometry and reports HGL/EGL, Reynolds number, friction factor and local losses.

Hydraulic condition

Variable conocidaFlow rate Q · Desnivel z₂ − z₁ · Density · Dynamic viscosity ·

Tramos consecutivos

1L · D · ε · ΣK

2L · D · ε · ΣK

3L · D · ε · ΣK

System flow rate

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ΔP requerida

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Friction + fittings loss

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Maximum velocity

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Rango Reynolds

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Factores Darcy

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Hydraulic profile · HGL and EGL

Energy equation

\[h_L=\sum_i\left(f_i\frac{L_i}{D_i}+K_i\right)\frac{V_i^2}{2g}\]

\[f=\frac{0.25}{\left[\log_{10}\left(\frac{\varepsilon}{3.7D}+\frac{5.74}{Re^{0.9}}\right)\right]^2}\]

For Re < 2300, f=64/Re applies. The energy line includes the velocity head; HGL = EGL − V²/2g.

Series pipe system calculator

In pipes connected in series the flow rate is the same in every segment, but velocity changes with diameter. The total loss is the sum of the major friction losses and the minor losses from fittings.

Flow regime and friction factor

Reynolds	Modelo	Note
Re < 2300	f = 64/Re	Flujo laminar desarrollado
2300–4000	Zona transicional	Result sensitive to perturbations
Re > 4000	Swamee–Jain	Explicit Colebrook approximation

HGL and EGL

The energy grade line EGL represents z+p/ρg+V²/2g. The hydraulic grade line HGL excludes the velocity head, so the gap between them changes as the diameter changes.

Preguntas frecuentes

Is the factor f Darcy or Fanning?

It is Darcy. The Fanning factor is four times smaller and must not be mixed into the same equation.

How are valves and elbows included?

Add their K coefficients within the segment where they are installed.

Does the calculation account for pumps?

No. Pump head must be added to the overall balance as supplied energy.