Valves and fittings pressure drop equivalent length

Equivalent length in ft and m for common valves and fittings found in piping systems

1. Introduction
2. Equivalent length common valves - globe valve, ball valve, seat valve...
3. Equivalent length of common fittings - elbows, tee, reduction, enlargement...

1. Definition : pressure drop of piping elements

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 :

2. Equivalent length common valves

The following tables are detailing the equivalent length that can be used to calculate the pressure drop for the following type of valves :

• Globe valve
• Ball check valve
• Angle valve
• Swing check valve
• Plug valve
• Gate or ball valve

The 1st table gives the equivalent length in ft (US units)

The next table gives the equivalent length in m (SI units)

3. Equivalent length common fittings

The equivalent length of common fittings found in piping is given for :

• 45° elbows