Installation, Operation and Maintenance Manual
MAN 604-1A Rev. 6
March 2021
Maintenance
25
Section 5: Maintenance
stop setting
screw cover
stop setting screw
plug
Figure 19
5.2
Special Maintenance
If there are leaks in the cylinder/manual override or a malfunction in the mechanical
components, or in case of scheduled preventive maintenance, the actuator must be
disassembly and seals must be replaced with reference to the follow general sectional
drawing and adopting the following procedures.
!
WARNING
If the actuator can be operated, it is essential to take it to fail safe position, with the spring
totally extended, otherwise the actuator should be disassembled from the valve and follow
these steps.
•
Remove the plug (26) from the cover of the adjustment screw (20).
•
Record the length between end flange and stop-setting screw, as in Figure 19.
•
Bring the adjustment screw back to the maximum (26) to let the spring loosen.
!
WARNING
Before disassembling the cylinder, make sure the above operation of spring release is done.
