Flowserve LHS Hydraulic Heavy-Duty Actuator Series - Manual (Page 17)

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LHS Hydraulic Heavy-Duty Actuator Series FCD LFENIM0003-00-AQ 7/14
4.2 Spring Container Maintenance
The spring container does not require maintenance. The lubricating of internal parts is carried out during the
assembly and is not necessary during the normal life of the actuator. The substitution of the spring container is not
expected over the entire actuator life. However, accidental events may result in damage to this component. In these
cases, proceed as described in the following steps.
The spring container is a single welded module. In case of damage, the whole container must be disassembled
from the actuator and replaced with a new one equal to the original.
The removal of the spring container from the actuator has to be performed through the following steps. The
reference drawing is Figure 19.
a WARNING: Ensure that the hydraulic connection ports of the cylinder are disconnected. Also make sure that
all hydraulic supplies to the control unit and all power supplies are disconnected. Finally, make sure that the
actuator is in fail safe position, i.e. that it is not locked in a position with the spring compressed by means of
locking devices.
4.2.1 Unscrew and remove the travel-stop of the hydraulic cylinder (25). For removing the stop, refer to paragraph
2.3. If necessary, feed the hydraulic cylinder from the port on the head flange (19) at minimum necessary
pressure to facilitate the movement of the scotch-yoke and assure the total retraction of the piston rod (20).
Remove the pressure. This way the spring is fully extended.
4.2.2 Remove the cover (46) from the housing by unscrewing all of the locking components: hex screw (45),
hex head shoulder bolts (44) and eyebolts (42) plus upper nuts (43). Leave the studs (41) screwed into the
scotch-yoke housing (51).
4.2.3 Hook and hold in tension the spring container using the specific lifting lug located on the top of the spring
can. Care should be taken to choose a lifting system suitable for the weight of the spring container. Refer to
the weight table shown in Figures 24 and 25.
Locate the studs (57) that connect the scotch yoke housing with the spring container. Carefully unscrew the
nuts (56) and the studs (57). Pull out the whole spring container.
NOTE: take care to horizontally support the spring module during removal, so as not to damage the spring rod
or the stud threads.
Figure 19: Spring Can Exploded View
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