Typical Values ofLeq
Flow through Run
Flow through Branch
90° Standard Elbow
45° Standard Elbow
A fully-open gate valve is in a pipe with a diameter of 10 inches. What equivalent length
of pipe would cause the same head loss as the gate valve?
From Table 1, we find that the value of Leq/D for a fully-open gate valve is 10.
= (L/D) D
= 10 (10 inches)
= 100 inches
By adding the equivalent lengths of all components to the actual length of pipe in a system we
can obtain the Leq value for the entire piping system.