21
Installation, Operation and Maintenance Manual
MAN616_EAC Rev. 5
July 2020
Section 3: Operation and Use
Operation and Use
3.5
Setting 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 travel stop screws are screwed into the end flange of the pneumatic cylinder,
depending on actuator different configuration (i.e. spring to open or spring to close),
and spring cartridge.
The setting of the open valve position is performed by adjusting the travel stop screw on
the left side of the actuator.
The setting of the closed valve position is performed by adjusting the travel stop screw on
the right side of the actuator.
3.5.1
One Travel-stop-screw Screwed on the End Flange
Center of Pneumatic Cylinder
(Suitable only for ALGAS-QA models that no need damper action to reduce the operating
time in the last part of the cylinder stroke.)
For the adjustment of the travel stop screws proceed as follows:
(See Figures 16 and 17 on the next pages.)
1.
Loosen the lock nut (2) with a proper wrench (c2).
2.
If the actuator angular stroke is stopped before reaching the end position (fully open
or closed), unscrew the stop screw (1) by turning it anticlockwise with a proper
wrench (c1) , until the valve reaches the right position. When unscrewing the stop
screw, keep the lock nut still with a wrench so that the sealing washer (3) does not
withdraw together with the screw.
3.
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.
4.
Tighten the lock nut (2).