Equivalent Length vs. Minor Pressure Head Loss in Pipe and Duct Components

Calculate the equivalent length and minor pressure head loss in pipe and duct components using the Darcy-Weisbach equation and minor loss coefficients.

Calculator

Inputs

Minor Loss Coefficient (ξ) (dimensionless)

Flow Velocity (v) (m/s)

Fluid Density (ρ) (kg/m³)

Acceleration of Gravity (g) (m/s²)

Friction Coefficient (λ) (dimensionless)

Hydraulic Diameter (dh) (m)

Results

Minor Pressure Loss (Δp)-- Pa

Minor Head Loss (Δh)-- m

Equivalent Length (le)-- m

Surface Material	Absolute Roughness (10⁻³ m)	Absolute Roughness (feet)
Copper, Lead, Brass, Aluminum (new)	0.001 - 0.002	3.3 - 6.7×10⁻⁶
PVC and Plastic Pipes	0.0015 - 0.007	0.5 - 2.33×10⁻⁵
Epoxy, Vinyl Ester and Isophthalic pipe	0.005	1.7×10⁻⁵
Stainless steel, bead blasted	0.001 - 0.006	(0.00328 - 0.0197) 10⁻³
Stainless steel, turned	0.0004 - 0.006	(0.00131 - 0.0197) 10⁻³
Stainless steel, electropolished	0.0001 - 0.0008	(0.000328 - 0.00262) 10⁻³
Steel commercial pipe	0.045 - 0.09	1.5 - 3×10⁻⁴
Stretched steel	0.015	5×10⁻⁵
Weld steel	0.045	1.5×10⁻⁴
Galvanized steel	0.15	5×10⁻⁴
Rusted steel (corrosion)	0.15 - 4	5 - 133×10⁻⁴
New cast iron	0.25 - 0.8	8 - 27×10⁻⁴
Worn cast iron	0.8 - 1.5	2.7 - 5×10⁻³
Rusty cast iron	1.5 - 2.5	5 - 8.3×10⁻³
Sheet or asphalted cast iron	0.01 - 0.015	3.33 - 5×10⁻⁵
Smoothed cement	0.3	1×10⁻³
Ordinary concrete	0.3 - 1	1 - 3.33×10⁻³
Coarse concrete	0.3 - 5	1 - 16.7×10⁻³
Well planed wood	0.18 - 0.9	6 - 30×10⁻⁴
Ordinary wood	5	16.7×10⁻³