2 for liquids, Mm] 7.6, Φ ∆ ρ µ 1000 – Bronkhorst IN-FLOW User Manual
Page 15
BRONKHORST HIGH-TECH B.V.
9.17.022
page 15
1.4.2 For liquids
This calculation method can be used to determine the K
v
-value of the main orifice of a control valve.
K
p
v
v
=
⋅
Φ
∆
ρ
1000
Units:
Φ
v
= volume flow [m
3
/h]
ρ
= density at 20°C and 1 atm [kg/m
3
]
∆
p = delta p [bard]
The orifice bore diameter can be determined by:
[mm]
7.6
v
K
d =
On LFC's only one type of normally closed valve is available. Diameter of orifice can be calculated or looked
up in the table.
Diameter [mm]
K
v
Normally closed
∆
p max. [bard]
0,10
0,14
0,20
0,30
0,37
0,50
0,70
1,00
1,73 x 10
-4
3,39 x 10
-4
6,93 x 10
-4
1,56 x 10
-3
2,37 x 10
-3
4,33 x 10
-3
8,48 x 10
-3
1,73 x 10
-2
10
10
10
10
10
10
10
10
* For liquids having a dynamic viscosity: 15 cP <
µ
< 100 cP the K
v
value should be calculated according to:
K
p
v
v
=
⋅
⋅
Φ
∆
ρ
µ
1000
Units:
Φ
v
= volume flow [m
3
/h]
ρ
= density at 20°C and 1 atm. [kg/m
3
]
∆
p = delta p [bard]
µ
= dynamic viscosity [c
p
]
For maximum possible viscosity apply to factory