Duct fitting pressure drop coefficients for
round, diverging conical branch tees

From ASHRAE (1989), with permission

A5-6h.gif (11467 bytes)

Branch Cc,b

vb / vc

0

0.2

0.4

0.6

0.8

1.0

1.2

1.4

1.6

1.8

2.0

Cc,b

1.0

0.85

0.74

0.62

0.52

0.42

0.36

0.32

0.32

0.37

0.52


Main Cc,s

vs / vc

0

0.1

0.2

0.3

0.4

0.5

0.6

0.8

1.0

Cc,s

0.40

0.32

0.26

0.20

0.14

0.10

0.06

0.02

0