June 2021
Installation, Operation and Maintenance Manual
MAN 689 Rev. 6
28
Maintenance
Section 5: Maintenance
5.2.1
Replacement of Cylinder Seals
Refer to the following sectional drawing.
Measure the protrusion of the stop screw (26) with reference to the end flange (22)
surface, so as to be able to easily restore the setting of the actuator mechanical stop, once
the maintenance procedures have been completed.
1.
Remove the hydraulic cylinder from the pneumatic cylinder end flange by
unloosing the screws (26).
2.
Remove the nuts (16) and the washers (24) from the tie rods (18) at the end flange
(22) side.
3.
Slide off the end flange (22) and the tube (19).
4.
Remove the screws (2) and the cover (1).
5.
Unscrew the piston rod (20) threaded end from the adaptor bush (31) of guide
block (14).
6.
Slide off the piston rod (20) from the head flange (17).
7.
Disassemble the head flange (17) from the mechanism housing (8) by removing
the screws (15) only if the gasket (36) has to be replaced because damaged.
5.2.1.1
Seals Replacement
Prior to reassemble check that the actuator components are in good conditions and
clean. Lubricate all the surfaces of the parts, which move in contact with other
components, by recommended grease. If the O-ring must be replaced, remove the
existing one from its groove, clean the groove carefully and lubricate it with protective
grease film. Assemble the new O-ring into its groove and lubricate it with a protective
grease film (AGIP-ENI HTX-SIL if seals are in NBR/Viton or Neoprene rubber, with
Aeroshell Grease 7 if the seals are in Fluorosilicon rubber).
1.
Replace the O-rings (39-40) of the head flange (17).
2.
Replace the O-ring (42) and the guide sliding ring (41) of the piston (21).
3.
Replace the O-ring (40-43) of the end flange (22).
