FK 40 - Tri-Canada

Loss of head
calculation
Example:
Flow rate Q = 25 m≈/h
Straight pipe length l = 150 m
Diamet er DN = 50 mm
Elbow 90° 4 pieces
Free- f low valves 2 pieces
from diagram (page 16):
from table :
v = 3.5 m/s
H = 35 m/100 m pipe length
V
equivalent pipe length 4 elbows: l =1.1 ∞ 4 = 4.4m
bend
equivalent pipe length 2 free- flow valves: l =1.2 ∞ 2 = 2.4 m
slide
straight pipe length: l = 150.0 m
pipe
total pipe length l = 156.8 m
total
loss of head:
with laminar flow (high viscosities) the loss of head Δp can be calculated using the
V
Hagen-Poiseuille formula:
v =Q/A [m/s]
M
η [Pa s = kg/m s]
l [m]
d [m]
Δp [bar]
H ∪ 10 ∞ Δp V
V V