© Danfoss | 2020.11 | 7AQ3525315322en-010101
AFD 2 / VFG 2 (21) DN 15-250, VFG 22 (221) DN 65-250
ENGLISH
Safety Notes
Prior to assembly and commissioning
to avoid injury of persons and damages
of the devices, it is absolutely necessary
to carefully read and observe these instructions.
Necessary assembly, start-up, and maintenance
work must be performed only by qualified,
trained and authorized personnel.
Prior to assembly and maintenance work on the
controller, the system must be:
- depressurized,
- cooled down,
- emptied and
- cleaned.
Please comply with the instructions of the
system manufacturer or system operator.
Disposal instructions
This product should be dismantled
and its components sorted, if possible,
in various groups before recycling or
disposal.
Always follow the local disposal regulations.
Definition of Application
The controller is used for pressure reduction of
water and water glycol mixtures for heating,
district heating and cooling systems.
The technical data on the label plates determine
the use.
Scope of Delivery ❶
*) Impulse tube AF, accessory
Assembly
Admissible Installation Positions ❷
①media temperatures up to 150 °C:
Can be installed in any position.
②media temperatures > 150 °C.
Installation permitted only in horizontal
pipelines with the actuator oriented
downwards.
Installation Location and Installation
Scheme ❸
The valve is open without pressure and
is closing on rising pressure.
System must be protected behind the
pressure reducer by a safety monitoring unit ①.
Valve Installation ❹
1. Install strainer ①before the controller.
2. Rinse system prior to installing the valve.
3. Observe flow direction ②on valve body.
Flanges ③in the pipeline must be in
parallel position and sealing surfaces
must be clean and without any damage.
4. Install valve.
5. Tighten screws crosswise in 3 steps up to the
max. torque.
Actuator Installation ❺
The actuator stem must be screwed
into the valve stem. Spring on the
pressure actuator is factory adjusted
(released) for proper installation.
1. Remove the spindle protection cup and
release the valve spindle by removing the
nut, washer and cardboard tube.
2.
Align the actuator stem with the valve stem,
connect both stems and turn gently the whole
pressure actuator clockwise with both hands,
until the stems are fully connected (valve stem
fully screwed into the actuator stem).
3. Release the uninon nut by pulling out the
blocking spring.
4. Tight the union nut
5.
Release the pressure actuator by turning it
counter clockwise for approximately half a turn.
6. Observe the position of impulse tubes
connection to the valve and align the
actuator accordingly.
7. Hold the actuator in the position and tight
the union nut to the valve with 100- 120 Nm
torque.
Impulse Tube mounting ❻
• Which impulse tubes to use?
The impulse tube set AF (2×) ❻① can be
used: Order No.: 003G1391
or use the following pipes:
Stainless steel Ø 10×0.8
Steel Ø 10×1 DIN 2391
Copper Ø 10×1 DIN 1754
• The impulse tube ③ can be connected
directly to the valve ④
or to the pipeline ⑤.
⑥ ventilation socket, do not connect
impulse tube.
Connection to the valve ❼
1. Remove plug ①at the valve.
2. Screw in threaded joint G 1/4 ②with copper
seal, Torque 40 Nm.
- or -
Connection to the Pipeline ❽①
No connection downwards/upwards ②, could
bring dirt/air into an impulse tube.
1.
Cut pipe in rectangular sections ③and deburr.
2. For copper pipe:
insert sockets ④on both sides.
3. Verify the correct position of the cutting
ring ⑤.
4. Press impulse tube ⑥into the threaded joint
up to its stop.
5. Tighten union nut ⑦Torque 40 Nm.
When installing seal pots ❽⑧, please
observe the Installation Instructions
for the seal pots.
Insulation ❾
For media temperatures up to 120 °C the
pressure actuator may be insulated ①.
Dismounting ❿
Danger
Danger of injury by hot water
Prior to dismounting depressurize system or
use shut off valves on the impulse tubes! ①
Carry out dismounting in following steps: ②
1. Fasten pressure actuator with the safety
bands to the fixed points in surroundings
2. Before releasing the actuator, fully release
the union nut
3. Hold the pressure actuator with both
hands, and release it by turning it counter
clockwise ~30 turns. During turning, control
the actuator weight all the time to prevent
unexpected fall of detached actuator.
4.
Carefully remove the actuator from the valve.
Before installing actuator back to the valve,
setting spring must be fully released again.
Leak and Pressure Test ⓫
Observemax.
permitted pressure, see below.
The pressure behind the valve ② must not
exceed the pressure before the valve ①.
Observe nominal pressure ⑤ of the valve.
Prior to pressure tests, it is absolutely necessary
to remove the impulse tube at the valve ④.
Close connections with plugs G ¼ ISO 228.
Max. pressure [bar] with connected impulse
tube:
AFD 2 (cm2)32 80 160 320 640
bar 16 5 4 1,5 0,35
Max. test pressure [bar] with disconnected
impulse tube must not exceed the plant testing
pressure and must always be lower than 1.5 × PN.
Non-compliance may cause damages at the
controller ③.
Filling the System, Start-up ⓬
The pressure ②behind the valve must
not exceed the pressure ①before the
valve.
Non-compliance may cause damages at the
controller ③.
1. Open shut-off devices ④that are possibly
available at the impulse tubes.
2. Slowly open valves in the system.
3. Slowly open shut-off devices ⑤in the supply
flow.
4. Slowly open shut-off devices ⑥in the return
flow.
Putting out of Operation
1. Slowly close shut-off devices ⑤in the supply
flow.
2. Slowly close shut-off devices ⑥in the return
flow.
Setpoint Adjustment ⓭
Set-point range see rating plate ①
1. Start-up of system, see section ⓬.
2. Set flow rate at the fitting ②after the
pressure reducer ③,to about 50 % of max.
flow rate ④
3.
Adjustment of the pressure behind the valve ⑤
• Observe pressure indicators.
• Turning to the right ⑥increases the set-
point (stressing the spring)
• Turning to the left ⑦reduces the
set-point (un-stressing the spring)
4. The set-point adjuster ⑧may be sealed.
5. Release the not yet used pointer ⑨, move it
to the set position and fix it with the screw
Dimensions ⓮
Flanges: connection dimensions acc. to
DIN 2501, seal form C
