Calculating nominal length Select unit SI units US units Please use a decimal point as the separator! Calculation of pressure drop Flow rate m³/min Nominal length m Absolute working pressure bar Pipe inner diameter mm Pressure drop bar The nominal length of the pipeline is calculated by adding together the length of the straight pipeline and the equivalent lengths of the fittings installed. An estimate of the equivalent lengths of the fittings can be provided using the adjacent program or accepted on an approximate basis by adding 60% onto the length of the straight pipeline, e.g. nominal length = length of straight pipeline x 1.6. The calculation is valid for smooth pipes. Calculate the equivalent pipe length Piping diameter DN 25 40 50 80 100 125 150 200 250 300 400 Equivalent length [m] Number Knee bend 1.5 Bend R = 2d 0.3 Bend R = d 0.4 Outlet direction of T-piece 0.5 Branching direction of T-piece 1.5 Seat valve 5 Butterfly valve/ball valve 0.3 Check valve 2 Reduction to DN: 20 0.5 Equivalent pipe length of all fittings installed m
