Datasheet

4.2-14
VNB
Air
Flow Characteristics
In the sonic flow region: For a flow of 6000 (l/min)
VNB4 (Orifice ø25).....P1 ≅ 0.14MPa
VNB4 (Orifice ø20).....P1 ≅ 0.28MPa
VNB4 (Orifice ø15).....P1 ≅ 0.5MPa
<Air and other gases>
qEquation in the domain of subsonic flow
 Calculation by Cv factor
 Calculation by effective area
wEquation in the domain of sonic flow
 Calculation by Cv factor
 Calculation by effective area
Water
How to Read The Graph
How to Calculate Flow
In case of a flow of 100 l/min:
VNB4 (Orifice ø25).....P to 0.035MPa
VNB4 (Orifice ø20).....P to 0.08MPa
VNB4 (Orifice ø15)......P to 0.2MPa
How to Read The Graph
How to Calculate Flow
 Calculation by Cv factor
 Calculation by effective area
Note) Calculation error of fluid with viscosity of 50cSt
or less will be very small.
Q=4080·Cv· ·
∆P(P2+0.1013)
G
273
273+θ
······ l /min (ANR)
Q=226·S· ·
∆P(P2+0.1013)
G
273
273+θ
······ l /min (ANR)
Q=2040·Cv·(P1+0.1013) ·
1
G
273
273+θ
······ l /min (ANR)
Q=113·S·(P1+0.1013) ·
1
G
273
273+θ
······ l /min (ANR)
Q=14.2·Cv· ......l/min
10.2∆P
G
Q=0.8·S· ......l/min
10.2∆P
G
Symbol
Q : Flow rate (Air and other gases l/min(ANR))
(Water and other fluids l/min)
P: Pressure differential(P1—P2)
P1 : Upstream pressure (MPa)
P2 : Downstream pressure (MPa)
θ : Temperature of air and other gases (°C)
S : Effective area(mm
2
) S ≅ 17667. Nl/min
Cv : Cv factor ( / )
G : Specific gravity ( / ) Air/Water=1