OLGAS-H
– High pressure spring return hydraulic actuator
Use and maintenance manual
© Copyright by BIFFI Italia. All right reserved.
Pag. 37
Contents may change without notice
❑
Bring the adjustment screw back to the maximum (20) to let the
spring loosen.
Before disassembling the cylinder, make sure the above
operation of spring release is done.
5.2.1 Replacement of cylinder seal
1) Unscrew the plug (27) from the cylinder end flange
2) Measure the distance of the stop screw (21) with reference to the
end flange (26) surface, so as to be able to easily restore the
setting of the actuator mechanical stop, once the maintenance
procedures have been completed.
3) Unscrew the stop screw (21) by turning it anticlockwise with an
Allen wrench until the screw is completely with drawn inside the
end flange threaded hole.
4) Unscrew the nuts (28) from the tie rods (19) : they must be
gradually unscrewed all at the same time.
5) Slide off the end flange (26) and the tube (22).
6) If the actuator control unit requires the cylinder chamber head
flange side to be also filled with gas, and the piston rod seal ring
(51) to be replaced, remove the screw (36) and the cover (35).
Unscrew the piston rod (18) threaded end from the adaptor bush
(33) of the guide block (14). Slide off the piston rod (18) from the
head flange (34).
7) Disassemble the head flange (34) from the mechanism housing
(8) by removing the screws (17) only if the gaskets (46) and (48)
have to be replaced because damaged.
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 oil
(
SHELL Omala S4 WE 320 or equivalent
). If the O-ring must be
replaced, remove the existing one from its groove, clean the groove
carefully and lubricate it with protective oil film. Assemble the new O-
ring into its groove and lubricate it with a protective oil film.
1) Replace the O-ring (50) of the head flange (34).
2) Replace the O-ring (50) of the end flange (26).
To replace the piston rod seal rings (51) proceed as follows :
1) Remove the existing Teflon seal ring (51) with its O-ring from their
groove.
