Data sheet
Flow controller (PN 25)
AVQ - return and flow mounting
Description AVQ is a self-acting flow controller primarily for
use in district heating systems. The controller
closes when set max. flow is exceeded.
The controller has a control valve with adjustable
flow restrictor and an actuator with one control
diaphragm.
Main data:
• DN 15-50
• kVS 1.6 -25 m3/h
• Flow range 0.03-15 m3/h
• PN 25
• Flow restrictor ∆p: 0.2 bar
• Temperature:
- Circulation water / glycolic water up to 30%:
2 … 150 ˚C
• Connections:
- Ext. thread (weld-on, thread and flange
tailpieces)
- Flange
Ordering
Example:
Flow controller; DN 15; kVS 1.6; PN 25;
flow restrictor ∆ p 0.2 bar;
T
150 °C; ext. thread
max
- 1× AVQ DN 15 controller
Code No: 003H6722
Option:
- 1× Weld-on tailpieces
Code No: 003H690 8
The controller will be delivered
completely assembled, inclusive
impulse tube bet ween valve and
actuator.
AVQ Controller
Picture
DN k
(mm) (m3/h)
15
20 6.3 G 1 A 003H 6725
25 8.0 G 1¼ A 003H6726
32 12. 5 G 1¾ A 003H 6727
40 16 G 2 A 003H 6728
50 20 G 2½ A 003H6729
32 12. 5
40 20 003 H6731
50 25 003H 6732
VS
1.6
2.5 003H6723
4.0 003H 6724
Cylindr. ext. thread
acc. to ISO 228/1
Connection Code No.
003H 6722
G ¾ A
003H 6730
Flanges PN 25, acc. to EN 1092-2
© Danfoss | 2022.02 AI173286472538en-010602 | 1
Data sheet AVQ (PN 25)
Ordering (continuous)
Accessories
Picture Type designation DN Connection Code No.
15
20 003H6909
Weld-on tailpieces
25 003H 6910
32 0 03H 6911
−
40 003H6912
50 003 H6913
15
R ½ 003H6902
20 R ¾ 003H6903
External thread tailpieces
25 R 1 003H6904
32 R 1¼ 003H6905
Conical ex t. thread acc. to
EN 10226 -1
40 R 1½ 065B2004
50 R 2 065B2005
15
Flange tailpieces
20 003H6916
Flanges PN 25, acc. to EN 1092-2
25 003H6 917
Service kits
Picture Type designation DN kVS (m3/h) Code No.
1.6 003H6863
Valve insert
15
20 6.3 003H6866
25 8.0 003H6867
32 / 40 / 50 12.5 / 16 / 20 / 25 003H6868
2.5 003H6864
4.0 003H6865
003H6908
003H6 915
Technical data
Fixed set ting (bar) Code No.
Actuator
0.2 003H6 841
Valve
Nominal diameter DN 15 20 25 32 40 50
k
value
VS
Range of max.
flow setting
pb 1) = 0.2 bar
from
to
or to
3)
Cavitation factor z ≥ 0.6 ≥ 0.55 ≥ 0.5
Leakage acc. to standard IEC 534 % of k
Nominal pressure PN 25
Min. differential pressure
Max. differential pressure 20 16
Medium Circulation water / glycolic water up to 30%
Medium pH Min. 7, max. 10
Medium temperature ˚C 2 … 150
valve External thread External thread and flange
Connections
Valve body
tailpieces
thread Red bronze CuSn5ZnPb (Rg5)
flange -
Valve seat Stainless steel, mat. No. 1.4571
Valve cone Dezincing free brass CuZn36Pb2As
Sealing EPDM
Pressure relieve system
1)
pb - differe ntial pressure over flow restri ctor
2)
Depends o n the flow rate and valve kVS ; For Q
3)
Higher ma x flow are achieved at high er differential pressur es over AVQ controller. In general at Δp > 1-1. 5 bar
4)
Flange valve bod y
1.6 2.5 4.0 6.3 8.0 12. 5 16/2 0 4)20/25
0.03 0.07 0.07 0.16 0.2 0.4 0.8 0.8
m3/h
0.86 1.4 2.2 3.0 3.5 8.0 10 12
0.9 1.6 2.4 3.5 4.5 10 12 15
VS
bar
≤ 0.02 ≤ 0.05
see remark
2)
Weld-on and external thread
Flange -
Materials
EN-GJS-400-18-LT (GGG 40.3)
Piston
= Q
-> p
set
max
≥ 0.5 bar; For Q
min
< Q
->
set
p
max
min
2
Q
k
VS
Ductile iron
p
b
4)
2 | AI173286472538en-010602 © Danfoss | 2022.02
Data sheet AVQ (PN 25)
Technical data (continuous)
Application principles
- Return mounting
- Flow mounting
Actuator
Typ e AVQ
Actuator size cm
Nominal pressure PN 25
Flow restrictor diff. pressure bar 0.2
Actuator
housing
Diaphragm EPDM
Impulse tube Copper tube Ø 6 × 1 mm
Direct-connec ted heating system Indirectly connec ted heating system
Upper casing of diaphragm
Lower casing of diaphragm Dezincing free brass CuZn36Pb2As
2
Materials
Stainless steel, mat. No.1.4301
54
Installation positions
Direct-connec ted heating system
Up to medium temperature of 100°C the
controllers can be installed in any position.
For higher temperatures the controllers have
to be installed in horizontal pipes only, with a
pressure actuator oriented downwards.
Indirectly connec ted heating system
Electrical actuator
Note!
Installation positions for electrical actuators
AMV(E) have to be observed as well. Please see
relevant Data Sheet.
AI173286472538en-010602 | 3© Danfoss | 2022.02
Data sheet AVQ (PN 25)
Pressure temperature
diagram
Maximum allowed operating pressure as a function of medium temperature (according to EN 1092-2 and EN 1092-3).
EN-GJS- 400-18-LT (GGG 40.3) PN 25
CuSn5ZnPb (Rg5) PN 25
Flow diagram
Sizing and setting diagram
Relation between actual flow and number of revolutions on flow restictor. Values given are approximate.
DN 50 k
20 / 25
DN 32 k
VS
12. 5
VS
DN 15 k
DN 15 k
DN 25 k
DN 20 k
DN 15 k
2.5
VS
1.6
VS
DN 40 k
8.0
VS
6.3
VS
4.0
VS
16 / 20
VS
1 = 360 º
Flow can be adjusted by turning flow restrictor screw
counter-clockwise as shown in this diagram.
Water flow shown at differential pressure across flow
Remark:
Controllers D N 40 and DN 50 have the same curve up to 9 r evolutions.
Note:
For max flow s etting on the controller di agrams from Instructions sh ould be used.
restrictor 0.2 bar (20 kPa) and across the controller
from 0.5 bar (50 kPa) to 16/20 bar (1600/2000 kPa).
4 | AI173286472538en-010602 © Danfoss | 2022.02
Data sheet AVQ (PN 25)
Sizing
- Directly connected heating
system
Example 1
Motorised control valve (MCV) for mixing circuit
in direct-connected heating system requires
differential pressure of 0.3 bar (30 kPa) and flow
less than 600 l/h.
Given data:
Q
= 0.6 m3/h (600 l/h)
max
p
= 0.9 bar (90 kPa)
min
1)
p
= 0.1 bar (10 kPa)
circuit
p
= 0.3 bar (30 kPa) selected
MCV
pb 2) = 0.2 bar (20 kPa)
Remark:
1)
∆p
corresponds to the r equired pump pressure in the
circuit
heating circuit a nd is not to be considered when sizin g the
AVQ.
2)
∆pb is differe ntial pressure over flow restri ctor.
The total (available) pressure loss across the
controller is:
p
= p
−p
AVQ, A
p
= 0.6 bar (60 kPa)
AVQ, A
min
= 0.9−0.3
MCV
Possible pipe pressure losses in tubes, shut-off
fittings, heatmeters, etc. are not included.
Q
max
Select controller from flow diagram, page 4,
with the smallest possible kVS value considering
available flow ranges.
kVS = 1.6 m3/h
The min. required differential pressure across
the selected controller is calculated from the
formula:
Δp
p
p
Q
=
MINAVQ,
= 0.34 bar (34 kPa)
AVQ, MIN
> p
AVQ, A
AVQ, MIN
k
max
VS
2
Δp
b
2
0,6
=+
1,6
0,2
+
0.6 bar > 0.34 bar
Solution:
The example selects AVQ DN 15; kVS value 1.6;
flow setting range 0.03-0.9 m3/h.
∆p
∆p
min
AVQ
∆p
b
∆p
AVQ
AVQ
Q
max
min
∆p
b
∆p
AVQ
∆p
∆p
MCV
MCV
∆p
∆p
circuit
circuit
AI173286472538en-010602 | 5© Danfoss | 2022.02
Data sheet AVQ (PN 25)
Sizing (continuous)
- Indirectly connected heating
system
Example 2
Motorised control valve (MCV) for indirectly
connected heating system requires differential
pressure of 0.3 (30 kPa) bar and flow less than
190 0 l/h.
Given data:
Q
= 1.9 m3/h (1900 l/h)
max
p
= 1.1 bar (110 kPa)
min
p
p
pb 1) = 0.2 bar (20 kPa)
Remark:
1)
∆pb is differe ntial pressure over flow restri ctor
= 0.1 bar (10 kPa)
exchanger
= 0.3 bar (30 kPa) selected
MCV
The total (available) pressure loss across the
controller is:
p
= p
AVQ, A
= 1.1−0.1−0.3
p
= 0.7 bar (70 kPa)
AVQ, A
min
−p
exchanger
−p
MCV
Possible pipe pressure losses in tubes, shut-off
fittings, heatmeters, etc. are not included.
Q
max
Select controller from flow diagram, page 4,
with the smallest possible k
available flow ranges.
value considering
VS
kVS = 4.0 m3/h
The min. required differential pressure across
the selected controller is calculated from the
formula:
Δp
MINAVQ,
p
= 0.43 bar (43 kPa)
AVQ, MIN
∆p
> ∆p
AVQ, A
AVQ, MIN
2
Q
max
Δp
b
k
VS
2
1.9
4.0
0.2
0.7 bar > 0.43 bar
Solution:
The example selects AVQ; DN 15; kVS value 4.0;
flow setting range 0.07-2.4 m3/h.
∆p
∆p
∆p
∆p
exchanger
exchanger
min
AVQ
∆p
b
∆p
AVQ
AVQ
Q
max
min
∆p
b
∆p
AVQ
∆p
∆p
MCV
MCV
6 | AI173286472538en-010602 © Danfoss | 2022.02
Data sheet AVQ (PN 25)
Design
1. Cover
2. Adjustable flow restrictor
3. Valve body
4. Valve insert
5. Pressure relieved valve cone
6. Valve stem
7. Built-in spring for flow rate
control
8. Control drain
9. Control diaphragm
10. Union nut
11. Upper casing of diaphragm
12. Lower casing of diaphragm
13. Impulse tube
14. Compression fitting for
impulse tube
Function
Flow volume causes pressure drop across the
adjustable flow restrictor. Resulting pressures are
being transferred through the impulse tubes
and/or control drain in the actuator stem to the
actuator chambers and act on control diaphragm
for flow control. The flow restrictor diff. pressure
is controlled and limited by means of built-in
spring for flow control. Control valve closes on
rising differential pressure and opens on falling
differential pressure to control max flow.
Settings Flow setting
Flow setting is being done by the adjustment of
the flow restrictor position. The adjustment can
be performed on the basis of flow adjustment
diagram (see relevant instructions) and/or by the
means of heat meter.
AI173286472538en-010602 | 7© Danfoss | 2022.02
Data sheet AVQ (PN 25)
Dimensions
L
3
L
2
L
1
d
2
n
d
SW
R
SW
k
SW
DN R
1)
SW d L
2)
L2L
1
mm
k d
3
2
n
15 ⁄ 32 (G ⁄A) 21 130 120 139 65 14 4
20 ⁄ 41 ( G 1A) 26 15 0 131 154 75 14 4
25 1 50 (G 1⁄A) 33 160 14 5 159 85 14 4
32 1⁄ 63 (G 1¾A) 42 - 177 184 100 18 4
40 1 ⁄ 70 (G 2A) 47 - 200 204 110 18 4
50 2 82 (G 2½A) 60 - 24 4 234 125 18 4
1)
Conical ex t. thread acc. to EN 10226-1
2)
Flanges PN 25, acc. to EN 1092-2
DN 15-25 DN 32-50 DN 32-50
DN 15 20 25 32 40 50
L
L1 - - - 180 200 230
H 109 109 10 9 150 150 15 0
H1 - - - 15 0 150 150
H2 73 73 76 103 103 103
H3 - - - 103 103 103
Weight (thread)
Weight (flange) - - - 9.8 11. 4 13.5
Note: other flan ge dimensions-see table for tail pieces.
65 70 75 100 11 0 130
mm
2.7 2.7 2.9 5.3 5.5 6 .1
kg
© Danfoss | DCS-SGDPT/SI | 2022.028 | AI173286472538en-010602
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