Flowserve LHS Hydraulic Heavy-Duty Actuator Series - Manual (Page 13)

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LHS Hydraulic Heavy-Duty Actuator Series FCD LFENIM0003-00-AQ 7/14
3
Field Conversion
Field Conversion from Fail CW to Fail CCW or vice versa (Spring Return)
NOTE:
• The actuator designation needs to be suitably changed on the name plate.
• An additional adapter kit is required for field conversion from Fail CW to CCW and vice versa.
There are two different situations, requiring different sequences of instructions: in the first situation, the actuator is
already disassembled from the valve. The second situation regards the conversion with the actuator assembled on the
valve. The reference drawings are Figures 19, 20, 21 and 22.
3.1 Actuator Disassembled From the Valve
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.
3.1.1 Unscrew and remove the end stop (25) from the hydraulic cylinder. For
removing the stop, refer to paragraph 2.3. If necessary, feed the hydraulic
cylinder 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. In this way the spring is fully
extended. Remove the cover (46) from the housing by unscrewing all of
the locking components: hex screws (45), hex head shoulder bolts (44)
and eyebolts (42) plus upper nuts (43). Leave the studs (41) screwed into
the housing (51).
3.1.2 Remove the spring can, carefully following the instructions given in
paragraph 4.2. Manually rotate the scotch yoke (36) counterclockwise (or
clockwise, depending on the original fail configuration) up to a position of
approximately 45°. Locate the studs (57) that connect the housing to the
hydraulic cylinder. With the scotch-yoke rotated of 45°, it is possible to
easily access these studs. Carefully unscrew the nuts (56) and the studs
(57). Pull out the whole hydraulic cylinder (The stem is fully retracted).
NOTE: Take care during removal, so as not to damage the piston rod or the stud threads.