Installation, Operation and Maintenance Manual
MAN 575 Rev. 4
July 2020
23
Maintenance
Section 5: Maintenance
If the sealing washer (17) must be replaced, measure the protrusion of the stop screw (30)
with reference to the end flange surface (4), so as to be able to easily restore the setting of
the actuator mechanical stop, once the maintenance procedures have been completed.
1.
Loosen the lock nut (10) and remove the travel stop screw (30) together with the
nut (10), the washer (28) and the sealing washer (17).
2.
Remove the sealing washer from the travel stop screw. Carefully clean and
lubricate the travel stop screw thread and the surface of the end flange area,
where the sealing washer is.
3.
Screw the new sealing washer onto the travel stop until it is in contact with the nut
(10). Assemble the washer (28) onto the sealing washer (17).
4.
Screw the travel stop screw into the threaded hole of the end flange until it reaches
its original position (the same protrusion with reference to the flange surface).
5.
Check that the sealing washer (17) and the washer (28) are in contact with the
flange surface.
6.
Tighten the lock nut (10).
Reassemble
1.
Assemble the new cylinder gaskets (7) on its seat on the housing and on the end
flange (4).
2.
Carefully clean the inside of the tube (13) and check that the entire surface,
particularly that of the bevels, is not damaged. Lubricate the inside surface of the
tube and the bevels at the ends. Slide the cylinder tube onto the piston taking care
not to damage the piston O-ring (24).
3.
Assemble the end flange (4) centring it on the tube (13). Assemble the nuts (25)
onto the tie rods (14). Tighten the nuts to the recommended torque (see table),
alternating between opposite corners.
Replacement of mechanism seals
(see sectional drawing, Figure 15)
To replace the O-Rings of the shaft (6) proceed as follows:
1.
Remove the retainer ring (21).
2.
Disassemble the shoulder washer (8). Remove the existing O-Ring (23) from its groove.
Clean the groove and the shaft carefully and lubricate it with protective oil film.
3.
Assemble the new O-Ring into its groove and lubricate it with protective oil or a
grease film. Assemble the shoulder washer (8). Assemble the retainer ring (21).
4.
If the sealing washer (17) has to be replaced, measure the protrusion of the stop
screw (30) with reference to the housing (1) surface, so as to be able to easily
restore the setting of the actuator mechanical stop, once the maintenance
procedures have been completed.
5.
Loosen the lock nut (10) and remove the stop screw (30) together with the nut
(10), the washer (28) and the sealing washer (17). Remove the sealing washer (17)
from the stop screw (30). Carefully clean and lubricate the stop screw thread and
the surface on the housing area, where the sealing washer is.
6.
Screw the new sealing washer onto the stop screw until it is in contact with the nut
(10). Assemble the washer (28) onto the sealing washer (17).
