For pump selection in heating, cooling and process water installations, the pressure loss of the pipeline must be known. This tool calculates the pressure loss in steel pipes by the Darcy-Weisbach method using the density and viscosity (IAPWS-IF97 / IAPWS-2008) that varies according to the temperature of the water.
Formula
f: Swamee-Jain coefficient of friction, default roughness 0.045mm (new steel pipe). For elbow, valve and fitting losses, ΣK can be entered in the advanced settings.
Example
In an EN 10255 DN50 pipe (inner diameter 53.1 mm), when 10 m³/h of water flows at 70 °C, the velocity is 1.25 m/s and the unit pressure loss is 303 Pa/m. In the 100 m line, the loss is 30.3 kPa, i.e. approximately 3.2 mWC.
Heating installations typically aim for 100–150 Pa/m and 0.5–1.5 m/s; use the water pipe diameter calculation for the appropriate diameter. You can consult Çiftel Kazan engineers for your boiler room and plumbing project.