When calculating the pressure drop in a pipe, the pressure drop due to singularities, typically valves and fittings, can be calculated thanks to a pressure drop coefficient. However, another method consists in considering that the fitting is equivalent in terms of pressure drop, to a certain longer of straight pipe. This length is called "equivalent length".
This page is giving the equivalent length of some common fittings and valves, it can be especially useful for shortcut calculation during preliminary studies or troubleshooting.
For pressure drop calculations, you can also revert to the following pages :
The following tables are detailing the equivalent length that can be used to calculate the pressure drop for the following type of valves :
The 1st table gives the equivalent length in ft (US units)
The equivalent length of common fittings found in piping is given for :
The data are given in ft or in m.