Datasheet
For air
For water
How to find the flow rate for water
• Formula based on Cv factor
Q = 14.2⋅ Cv⋅ 10.2⋅ ∆P … l/min
• Formula based on effective area (Smm²)
Q = 0.8⋅ S⋅ 10.2⋅ ∆P …… l/min
How to find the flow rate for air
1. For subsonic range
Where P1 + 0.1013 = (1 to 1.8941) (P2 + 0.1013)
• Formula based on Cv factor
Q = 4073.4⋅Cv⋅ ∆P (P2 + 0.1013) … l/min (ANR)
• Formula based on effective area
Q = 226.3⋅S⋅ ∆P (P2 + 0.1013) …… l/min (ANR)
2. For sonic range
Where P1 + 0.1013≥1.8941 (P2 + 0.1013)
• Formula based on Cv factor
Q = 1972.8⋅ Cv⋅ (P1 + 0.1013) … l/min (ANR)
• Formula based on effective area
Q = 109.6⋅S⋅ (P1 + 0.1013) ….… l/min (ANR)
Q: Flow rate (l/min), ∆P: Pressure differential (P1—P2), P1: Upstream pressure (MPa)
P2: Downstream pressure (MPa), S: Effective area (mm²),
Cv: Cv factor
100
10
5.0
1.0
0.1
0.001 0.01 0.1 1 10
Pressure differential ∆P = (P
₁ – P₂)
MPa
Flow rate Ql /min
1. Materials
NBR: Nitrile rubber
FKM: Fluoro rubber – Trade names: Viton®, Dai-el, etc.
Other
Viewing
the graph
VDW30 ø2 CV = 0.16ø2 CV = 0.16
VDW20 ø2.3 CV = 0.18ø2.3 CV = 0.18
VDW30 ø4 CV = 0.39ø4 CV = 0.39
VDW20 ø3.2 CV = 0.3ø3.2 CV = 0.3
VDW30
ø2 CV = 0.16
VDW10 ø1 CV = 0.03ø1 CV = 0.03
VDW VDW
ø1.6 CV = 0.07ø1.6 CV = 0.07
10
20
VDW10
ø1 CV = 0.03
VDW
ø1.6 CV = 0.07
10
20
VDW20
ø2.3 CV = 0.18
VDW30 ø3 CV = 0.28ø3 CV = 0.28VDW30
ø3 CV = 0.28
VDW30
ø4 CV = 0.44
VDW20
ø3.2 CV = 0.3
The sonic range pressure to generate a flow rate of 300l/min (ANR)
for orifice ø2.3 (VDW20) is P1 approx. 0.77MPa,
for orifice ø3 (VDW30) is P1 approx. 0.45MPa,
for orifice ø4 (VDW30) is P1 approx. 0.24MPa.
Viewing
the graph
Explanation of Terminology
Pressure Terminology
1. Maximum operating pressure differential
This indicates the maximum pressure differential (upstream
and downstream pressure differential) which can be allowed
for operation with the valve closed or open. When the
downstream pressure is 0MPa, this becomes the maximum
operating pressure.
2. Maximum operating pressure
This indicates the limit of pressure that can be applied inside
the pipelines. (line pressure)
(The pressure differential of the solenoid valve unit must be no
more than the maximum operating pressure differential.)
3.
Withstand pressure
The pressure which must be withstood without a drop in
performance after returning to the operating pressure range.
(the value under the prescribed conditions)
Electrical Terminology
1. Surge voltage
A high voltage which is momentarily generated in the shut-off unit
by shutting off the power.
To generate a water flow of 4l/min at a differential pressure of
0.1MPa, an effective area with Cv factor 0.28 (VDW30ø3) or
more is required.
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1.0
0
.95
0.95
0
.90.9
0.850.85
0.80.8
0
.7
5
0.75
0.70.7
0.650.65
0.60.6
0.5
5
0.55
0.50.5
0.30.3
0.250.25
0.20.2
0.10.1
0.050.05
0
.95
0
.9
0.85
0.8
0
.7
5
0.7
0.65
0.6
0.5
5
0.5
0.450.450.45
0.40.40.4
0.350.350.35
0.3
0.25
0.2
0.150.150.15
0.1
0.05
S = 0.54
S = 1.2
S = 3.2
S = 5.8
S = 2.8
S = 5.0
S = 8.0
VDW10ø1
VDW ø1.6
VDW20ø2.3
VDW20ø3.2
VDW30ø2
VDW30ø3
VDW30ø4
6050403020
1251007550
10
35030025020015010050
600500400300200100
30025020015010050
600500
400300200100
900800700
600500400300200
10
20
Downstream pressure of valve (P2) MPa
Upstream pressure of valve P
₁ = 1.0MPa
Critical
pressure
Subsonic
Sonic
Flow rate Q l/min (ANR)
Series VDW
Model Selection
15