Example

A fully-open gate valve is in a pipe with a diameter of 10 inches. What is the equivalent length of pipe which would cause the similar head loss as the gate valve?

Solution:

From the table shown below, we find that the value of L_eq/D for a fully-open gate valve is 10.

L_eq = (L/D) D

      = 10 (10 inches)

      = 100 inches

By adding up the equivalent lengths of all components to the real length of pipe in a system we can acquire the L_eq value for the whole piping system.