Samson 3766 - Page 29

EB 8355-1 EN 29
Mounting on control valves
Single-acting rotary actuator with spring-return mechanism
Linear cam disk (equal percentage cam disk is represented by a broken and dotted line)
Control valve opens counterclockwise
For valves that open clockwise, the cam disk must be turned over so that lever with feeler roll moves
over the same disk segments as shown in the images below, but with the cam disk turning clockwise.
Fail-safe position: Fail-close valve
Direct operating direction >> Reverse operating direction <>
Ref. variable Sig. pressure Valve Characteristic Ref. variable Sig. pressure Valve Characteristic
increases increases opens N decreases increases 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
Fail-safe position: Fail-open valve
Direct operating direction >> Reverse operating direction <>
Ref. variable Sig. pressure Valve Characteristic Ref. variable Sig. pressure Valve Characteristic
decreases decreases opens I increases decreases opens N
90˚
60˚
30˚
0˚
90˚
60˚
30˚
0˚
Feeler roll
Starting point N
Starting point I
Alignment at max. signal pressure
Fig.8: Cam disk settings for single-acting actuators