Dimensions in mm
This data sheet is designed as a guide and should not be regarded as wholly accurate in every detail. We reserve the right to amend the specification of any product without notice.
ART24 Differential Pressure
Control Valve (DPCV)
Page 15
If in an operational case (case B) a generic control valve V closes the
fl
ow rate in an emitter
and the regulated pressure is maintained constant (for example with a DPCV), the
fl
ow in
all the sections from 1 to k decreases by q
m,V,A
and the pressure drop decreases to:
The pressure drop in a section
i
in the design case
Δ
p
i,A
, can be expressed approximately
by an equivalent resistance R
i
:
When the water
fl
ow changes, the equivalent resistance remains constant. If the
fl
ow is
reduced by q
m,V,A ,
the variation of pressure in a generic sector is:
Section
Ri
Δ
p
i,B
kPa/(l/h)
2
E1
E2
E3
E4
E5
kPa
kPa
kPa
kPa
kPa
1
28.93*10
-6
3.70
3.88
5.19
5.12
4.91
2
19.09*10
-6
1.00
1.56
1.53
1.44
3
36.73*10
-6
0.91
0.88
0.78
4
40.62*10
-6
0.28
0.23
5
31.82*10
-6
0.00
Con.1
57.21*10
-6
Con.2
47.48*10
-6
Con.3
56.43*10
-6
Con.4
40.20*10
-6
Con.5
41.39*10
-6
∑Δ
p
i,B
3.70
4.88
7.66
7.81
7.36
If the control valve V is designed with a pressure drop
Δ
p
V,A
, its authority is:
Using a minimum authority that is introduced for control engineering reason (i.e. a
v
>0.3), it
is possible to check if the selected valves are suitable.
Emitter
E1
E2
E3
E4
E5
-
Section from 1 to
1
2
3
4
5
-
Connection pipe
Con.1
Con.2
Con.3
Con.4
Con.5
-
Δ
p
V,A
5.24
4.60
2.77
2.99
3.72
kPa
Δ
p
reg
16.78
kPa
Δ
p
bal
3.12
1.63
2.20
1.03
0.00
kPa
∑Δ
p
i,B
3.70
4.88
7.66
7.81
7.36
kPa
a
v
0.40
0.39
0.30
0.33
0.40
-
