Datasheet

Series VXZ
Flow-rate Characteristics
Note) Use this graph as a guide. In the case of obtaining an accurate flow rate, refer to pages 31 through to 35.
How to read the graph
The pressure differential for a ø10 orifice to
supply a flow of 25 L/min (VXZ2
3
A
, port size
3/8) will be ΔP ≈ 0.05 MPa.
The optimum size for a pressure differential of
ΔP ≈ 0.4 MPa and a flow of 50 L/min will be
the VXZ2
3
A
(ø10 orifice, port size 1/4).
For Air
For Water
(P1 + 1.033) = (1 to 1.89)(P2 + 1.033)
Upstream pressure of valve P
1
1.0 MPa
Sonic
Critical
pressure
Downstream pressure of valve (P2) [MPa]
1.0
0.9
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
VXZ2 Port size 1/4
VXZ2 Port size 3/8
VXZ2
VXZ2
VXZ2
3
A
3
A
4
B
5
C
6
D
0.9
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
1,000 2,000 3,000
1,000 2,000 4,0003,000
2,000 4,000 6,000 8,000 10,000
5,000 10,000 15,000 20,000
5,000 10,000 15,000 20,000
Flow rate Q [L/min]
ø10
ø10
ø15
ø20
ø25
(P1 + 1.033) ≥
1.89 (P2 + 1.033)
Flow rate Q [L/min]
Pressure differential ΔP (P1 − P2) [MPa]
500
400
300
200
100
50
40
30
25
20
10
0.01 0.02 0.03
0.04 0.05 0.1 0.2 0.3 0.4 0.5
VXZ2
ø
25 Cv = 12
6
D
VXZ2
ø
20 Cv = 9.2
5
C
VXZ2
ø
15 Cv = 5.3
4
B
3
A
3
A
How to read the graph
The sonic range pressure to generate a flow of
6,000 L/min (ANR) is P1 ≈ 0.47 MPa for a ø15
orifice (VXZ2
4
B
) and P1 ≈ 0.23 MPa for a ø20
orifice (VXZ2
5
C
).
The optimum size for an upstream pressure P1
= 0.45 MPa and a flow of 6,000 L/min will be
the VXZ2
4
B
(ø15 orifice, port size 1/2).
Subsonic
VXZ2
Port size 3/8
ø
10 Cv = 2.4
VXZ2
Port size 1/4
ø
10 Cv = 1.9
34