Pipe Pressure Loss Calculation

Calculate pipe pressure loss from fluid properties, flow rate, inner diameter, pipe length, and equivalent length from fittings.

Before calculating pressure drop, you can check pipe velocity or estimate pipe inner diameter from flow rate.

STEP 1

Enter Pipe and Fluid Conditions

Enter fluid density, viscosity, flow rate, pipe dimensions, and the output pressure unit.

mm

m

Number of Fittings and Valves

Enter the quantity for fittings and valves if equivalent length should be included.

Fitting and valve quantities for equivalent length
Type of fitting or valve Quantity
45° Elbow
90° Elbow (Standard Radius)
90° Elbow (Medium Radius)
90° Elbow (Long Radius)
90° Bend (R/D = 3)
90° Bend (R/D = 4)
180° Bend
Cross
Tee
Gate Valve (Fully Open)
Gate Valve (1/4 Closed)
Gate Valve (1/2 Closed)
Gate Valve (2/3 Closed)
Globe Valve (Fully Open)
Angle Valve (Fully Open)

Calculation Result

Enter pipe conditions and press Calculate to see pressure loss.

Formula

This calculation determines the pressure loss Delta P in the pipe using Fanning's equation.

Delta P = 4 f (rho u^2 / 2) (L / D)

1 / sqrt(f) = 3.2 log10(Re / sqrt(f)) + 1.2

Check the Reynolds number and flow regime

  • Delta P: pressure loss
  • f: friction factor
  • rho: fluid density
  • u: average velocity in the pipe
  • L: pipe length, including equivalent length from fittings and valves
  • D: pipe inner diameter
  • mu: fluid viscosity