Samson 3766 - Page 30

30 EB 8355-1 EN
Mounting on control valves
Double-acting, springless rotary actuator with reversing amplier
Linear cam disk (equal percentage cam disk is represented by a broken and dotted line)
View from the positioner onto the actuator shaft
Control valve opens counterclockwise – Based on a closed valve
Direct operating direction >> Reverse operating direction <>
Ref. variable Signal pressure Valve
Charac-
teristic
increases
A1 increases, A2
decreases
opens
N
Ref. variable Signal pressure Valve
Charac-
teristic
decreases
A1 increases, A2
decreases
opens
I
90˚
60˚
30˚
0˚
90˚
60˚
30˚
0˚
Feeler roll
Starting point N
Starting point I
Hole to secure the cam disk
Insertclipandpresstheaps
outwards
View from the positioner onto the actuator shaft
Control valve opens counterclockwise – Based on a closed valve
Direct operating direction >> Reverse operating direction <>
Ref. variable Signal pressure Valve
Charac-
teristic
increases
A1 increases, A2
decreases
opens
N
Ref. variable Signal pressure Valve
Charac-
teristic
decreases
A1 increases, A2
decreases
opens
I
0˚
90˚
60˚
30˚
0˚
90˚
60˚
30˚
Feeler roll
Starting point N
Starting point I
Fig.9: Cam disk settings for double-acting actuators