view user manual (pdf) - dyna-flo control valves

Operation
Six valve characteristics are stored in the positioner
S linear (12.SFCT = Lin, factory setting)
S equal percentage 1 : 25 (12.SFCT = 1:25)
S equal percentage 1 : 33 (12.SFCT = 1:33)
S equal percentage 1 : 50 (12.SFCT = 1:50)
S inverse equal percentage 25 : 1 (12.SFCT = n1:25)
S inverse equal percentage 33 : 1 (12.SFCT = n1:33)
S inverse equal percentage 50 : 1 (12.SFCT = n1:50)
S freely adjustable (12.SFCT = FrEE)
13.SL0 to 33.SL20
Setpoint turning points
A flow parameter can be assigned to the respective setpoint turning
value at an interval of 5 %. These points lead to a polygon chain with
20 straight lines which therefore represents a projection of the valve
characteristic.
Tight closing
100%
x
Limit for
tight closing
Example:
39 YVLS = UP
41YCUP = 95.0
90
80
12 SFCT=FrEE
70
60
50
Setpoint turning point
Example:
18 SL5 = 45.0
Modulation duty
12 SFCT=Lin
40
30
Limit for
tight closing
Example:
39 YCLS = DW
40 YCDO = 12.5
20
12 SFCT=1--50
10
0
w
Tight closing
SL 0
0
10 20 30 40 50 60 70 80 90 100 %
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
Figure 4-9
Setpoint characteristic, manipulated variable standardization and tight closing function
SIPART PS2 Manual
A5E00074631-03
91