What is pressure loss? When a fluid flows through a pipe system, it creates a friction-related loss of pressure. Hence, this pressure loss describes the pressure difference that is caused by the wall friction in pipe systems and by resistances in valves or fittings. Formula for pressure loss The pressure loss for pumps is calculated by the head loss, which is independent of the density. The formula for pressure loss is: Formula for pressure loss pv is the pressure loss in Pa ρ is the density in g/m³ G is the gravitational acceleration of 9.81 m/s² Hv is the head loss in m Pressure losses are dependent on the length and diameter of the pipe system. Since pressure losses are always accompanied by an energy loss, they are an important factor in the dimensioning of the pump installation and thus are taken into account in the installation characteristic. Back