© Danfoss | 2021.08 | 7
AQ26905314366601-010203
AFP 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.
Definition of Application
The controller is used for diffe rential pressure control
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
①
media temperatures up to 150 °C:
Can be installed in any positi on.
②
media temperatures > 150 °C.
Installation permitted only in horizontal pipelines
with the actuator oriented downwards.
Installation Location and Installation
Scheme
❸
Return mounting
①
Flow mounting
②
Valve Installation
❹
1. Install strainer
①
before the controller.
2. Rinse system prior to installing the valve.
3. Observe flow direction
②
on valve body.
Flanges
③
in 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
DIN 17458,
DIN 2391
Steel
Ø 10×1
DIN 2391
Copper
Ø 10×1
DIN 1754
• Connection of impulse tubes
❻②
in the system
Installation in return flow
③
Installation in supply flow
④
Connection to the valve
❼
1. Remove plug
①
at the valve.
2. Screw in threaded joint G 1/4
②
with 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
③
and deburr.
2. For copper pipe:
insert sockets
④
on both sides.
3. Verify the correct position of the cutting ring
⑤
.
4. Press impulse tube
⑥
into the threaded joint
up to its stop.
5. Tighten union nut
⑦
Torque 40 Nm.
When installing seal pots
❽⑧
, please
observe the Installati on Instructions
for the seal pots.
Insulation
❾
For media temperatures up to 120 °C the pressure
actua tor may be insulated
①
.
Dismounting
❿
Danger
Danger of injury by hot water
Prior to dismounting depres surize 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
"Danger of injury by heavy weight of
pressure actuator. When dismounting
the pressure actuator from the valve,
control the actuator weight all the time
to prevent unexpected fall of detached actuator
and potential injuries due to the heavy weight!"
To prevent damages on the diaphragm pressure
must be constantly and simultaneously increased
at the + and − connection
①
until the max testing
pressure is reached.
In case of higher test pressu res, remove impulse tubes
at the pipelines
①
.
Observe nominal pressure
②
of the valve.
Max. test pres sure must not exceed the plant testing
pressure and must always be lower than 1.5 × PN
Non-compliance may cause damages at the actuator
or valve.
Filling the System, Start-up
⓬
The return flow pressure
①
must not
exceed the supply flow pressure
②
.
Non-compliance may cause damages at
the controller
③
.
1. Open shut-off devices
④
that are possibly
available at the impulse tubes.
2. Slowly open valves in the system.
3. Slowly open shut-off devices
⑤
in the supply flow.
4. Slowly open shut-off devices
⑥
in the return flow.
Putting out of Operation
1. Slowly close shut-off devices
⑤
in the supply flow.
2. Slowly close shut-off devices
⑥
in the return flow.
Differential Pressure Setting
⓭
Set-point range see rating plate
①
1. Start-up of system, see section
⓬
.
2. Set flow rate on a motorized valve
③
over
which the differential pressure is controlled,
to about 50 %
②
3. Adjustment
• Observe pressure indica tors
④
.
• Turning to the right
⑤
increases the set-point
(stressing the spring)
• Turning to the left
⑥
redu ces the
set-point (un-stressing the spring)
4. The set-point adjuster
⑦
may be sealed.
5. Release the not yet used pointer
⑧
, move it to the
set position and fix it with the screw
Dimensions
⓮
Flanges: connection dimensi ons acc. to DIN 2501, seal form C