27
Installation, Operation and Maintenance Manual
MAN 707 Rev. 3
Section 5: Maintenance
Maintenance
March 2022
Seals Replacement
Prior to reassembly, check that the actuator components are in good condition and are
clean. Lubricate all the surfaces of the parts which move in contact with other components,
by a recommended grease. If the O-ring must be replaced, remove the existing one from
its groove, clean the groove carefully and lubricate it with a protective oil or grease film.
Assemble the new O-ring into its groove and lubricate it with a protective oil or grease film.
1.
Replace the O-ring (17, Figure 22) of the head flange (31, Figure 22).
2.
Replace the O-ring (15, Figure 22) in the head flange groove for cylinder tube.
3.
Replace the external O-ring in the end flange groove (29, Figure 22).
To replace the piston seal rings (3), proceed as follows:
1.
Remove the existing Teflon seal ring (10, Figure 22) with its O-rings from
their groove.
2.
Clean the groove carefully and lubricate it with a protective oil or grease film.
3.
Assemble the new O-ring into its groove and lubricate it with a protective oil or
grease film.
4.
Assemble the new Teflon seal ring (10, Figure 22) into the flange groove, inside
its rubber O-ring, by bending it; take care that the bending radius is as large as
possible to avoid damaging the seal. Then, enlarge the seal ring with your fingers
so as to restore its round shape. Pay attention not to utilize any tools which can
damage the seal ring.
To replace the lower piston rod sealing, proceed as follows:
1.
Unscrew the fixing screws (12, Figure 22) to disassemble the lower seal flange
(4, Figure 22) from the lower stem (1, Figure 22).
2.
Remove the existing Glyd ring (28, Figure 22) from their groove.
3.
Clean the groove carefully and lubricate it with a protective oil or grease film.
4.
Assemble the new Glyd ring into its groove and lubricate it with a protective oil or
grease film.
5.
Replace also the scraper ring (24, Figure 22) and the sealing O-ring (16, Figure 22).
6.
Reassemble the lower seal flange with its fixing screws.
To replace the upper piston rod sealing, proceed as follows :
7.
Unscrew the fixing screws (11, Figure 22) to slide-off the upper seal flange
(5, Figure 22) from the upper stem (2, Figure 22).
8.
Remove the existing Glyd ring (27, Figure 22) from their groove.
9.
Clean the groove carefully and lubricate it with a protective oil or grease film.
10.
Assemble the new Glyd ring into its groove and lubricate it with a protective oil or
grease film.
11.
Replace also the scraper ring (23, Figure 22) and the sealing O-ring (13, Figure 22)
12.
Reassemble the upper seal flange with its fixing screws.