4 | © Danfoss | 2017.07
VI.GA.N6.81
AFT 06,17
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 instruction
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 actuator AFT.. is used in combination with
Danfoss valves for temperature control of water,
water-glycol mixtures, and steam for heating,
district heating, and cooling systems.
The technical data on the rating plates
determine the use.
Permissible Pressures and
Temperatures
❶
Mounting
❷
Permissible Installation Positions
①
For valves VFG 2., VFG 3., VFU 2
DN 15-80
media temperatures up to120 °C
②
For valves VFG 2., VFG 3., VFU 2
DN 100-125 and for DN 15-80,
media temperatu res > 120 °C
and
for valves VFGS 2
Installation Scheme
Valves VFG 2(1), VFGS 2, VFU
❸
Can be installed in both flow or the return pipe.
Mixing valve VFG 33
❹
①
Mixing valve in the supply
flow heating
②
Mixing valve in the supply
flow cooling
Valve Installation
❺
1. Install strainer in front of valve.
2. Rinse system before installing valve.
3. Observe flow direction
①
on the valve body.
Flanges
②
in the pipeline system must
be in parallel direction, the sealing
surfaces must be clean and undamaged.
4. Install valve.
5. Tighten screws crosswise in 3 steps up to the
maximum torque.
Actuator and Valve Mounting
❻
1. Place actuator at the valve and align.
2. Tighten union nut
①
, torque 100 Nm
Temperature Sensor Installation
❼
- The temperature sensor may be installed in
any position
- The capillary tube may not be twisted or
buckled. The minimum bending radius is
50 mm.
- The temperature of the media has to be
taken directly without any delay.
- Care for sufficient cross section of flow
②
.
Filling the system and First Start-up
❽
When filling the system, the temperature
control valve must be open. Alternatively, the
filling can be carried out from all sides.
To ensure that the temperature control valve is
open, the following must be observed:
The stem of the actuator:
is extended
①
if the temperature at the sensor
③
is
higher than the setpoint
④
.
is retracted
②
if the temperature at the sensor
③
is lower
than the setpoint
④
.
In order to open the temperature control valve,
the setpoint at the setpoint adjuster
⑤
is to be
increased or reduced, depending on the valve
designs
⑥
-
⑧
.
The pressure
②
behind the valve may exceed
the pressure
①
in front of the valve only
insignificantly.
Non-compliance may cause damages at the
valve.
Pressure test
➒
Carry out pressure tests only with the
actuator mounted.
Without actuator, the valve is open
③
,
the seal is in the actuator.
It is absolutely necessary to constantly
increase pressure from all sides.
Non-compliance may cause damages
at the controller.
Observe nominal pressure
④
of the valve.
Max. test pressure is 1.5 x PN
Setpoint Adjustment
❿
Thermostats are proportional controllers,
thus certain deviation from set point can be
expected and varies from valve DN.
The setpoint range is indicated on the rating
plate.
Adjustment
When the water temperature reaches
the set temperature,
VFG will be fully
closed, VFU will start opening.
1. Observe temperature indicator
①
.
2. Adjust setpoint by turning the setpoint
adjuster (observe the scale for relevant valve
VFG2/VFU2)
②
:
③
increases the setpoint
④
reduces the setpoint
If the temperature at the indicator
①
is noticeably higher than the setpoint
temperature, then:
- return setpoint adjuster only in increments
of max. 10 °C and
- wait until the temperature at the sensor
drops.
After having adjusted the setpoint, wait until
the temperature indication
①
shows its final
value.
Scale on the setting knob is only the
indication of the set temperature.
Temperature setting need to be done
based on the temperature reading from
the thermometer.
Dismounting of Valve
and Actuator
⓫
Danger of injury by steam or hot
water!
.
Valve without actuator is open
①
, sealing
②
is
in the actuator.
It is absolutely necessary to depressurize system
prior to dismounting.
Dimensions
⓬