July 2020
Installation, Operation and Maintenance Manual
MAN 575 Rev. 4
16
Operation and Use
Section 3: Operation and Use
3.4
Calibration of the Angular Stroke
It is important that the mechanical stops of the actuator (and not those of the valve) stop
the angular stroke at both extreme valve position (fully open and fully closed), except when
this is required by the valve operation (e.g. metal seated butterfly valves).
The setting of the angular stroke is performed by adjusting the travel stop screws of the
cylinder end flange and of the housing wall.
The setting of the open valve position is performed by adjusting the travel stop screw on
the left side of the actuator (screwed in the housing wall for spring to close actuators or in
the cylinder end flange for spring to open actuators).
The setting of the closed valve position is performed by adjusting the travel stop screw
on the right side of the actuator (screwed in the cylinder end flange for spring to close
actuators or in the housing wall for spring to open actuators).
For the adjustment of the travel stop screws proceed as follows:
(please refer to Figures 12 and 13 on following page)
1.
Loosen the lock nut with wrench C2
2.
If the actuator angular stroke is stopped before reaching the end position
(fully open or closed), unscrew with wrench C1 the travel stop screw by turning
it anticlockwise, until the valve reaches the right position. When unscrewing the
travel stop screw, keep the lock nut still with a wrench so that the sealing washer
does not withdraw together with the travel stop screw
3.
Tighten the lock nut refer to Table 4 to avoid accidental unscrewing of the lock-nut)
4.
If the actuator angular stroke is stopped beyond the end position (fully open or
closed valve), screw the stop screw by turning it clockwise until the valve reaches
the right position
5.
Tighten the lock nut (refer to Table 4 to avoid accidental unscrewing of the lock-nut)
Table 4.
Actuator Model
Thread
Wrench C2 (mm)
Torque (Nm)
RPD 15
M30X2
41
150
RPD 30
M40X2
50
350
RPD 60
M45X2
55
500
RPD 120
M50X2
60
800
