16
Technical Data
Type 3281
6.6.1
Derating
The maximum duty cycle of the valve depends on the maximum ambient temperatures, the media temperature
and the coil current of the stepper motor.
The duty cycle does not mean the duty cycle of the device but the duty cycle of the stepper motor.
This is only switched on when the valve is to move. Frequent set-point value changes drastically
increase the duty cycle of the motor.
From the derating curve it can be read which maximum duty cycle is permissible at which maximum ambient
temperature. At lower medium temperatures, higher duty cycles can be achieved.
10 %
20 %
30 %
40 %
50 %
60 %
70 %
80 %
90 %
100 %
0
5
10
15
20
25
30
35
40
45
50
55
60
Ambient temperature [°C]
Duty
cycle
[%]
Fig. 5:
Derating curve at max. media temperature for positioner and process controllers
6.7
Fluidic data
Type
Seat diameter
KV
s-value
[m³/h]
2)
Max. pressure [bar]
3281
4
0.57
See indication on the type label
6
1.25
8
1.8
10
2.25
2)
The KV
s
valueisaflowvalueforwater,measur20 °Cand1 barpressuredifferenceabovethefullyopen
valve.
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