Flowserve Mechanical and Hydraulic User Manual
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Mechanical and Hydraulic Overrides FCD LFENIM0004-00-AQ – 05/15
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2.2.2.2 Restoring Automatic Operation
To restore automatic operation:
2.2.2.2.1 Operate handwheel in order to retract the jackscrews completely and lock the position with the safety lock
1
.
2.2.2.2.2 Restore the supply pressure inside the actuator’s cylinder.
2.2.2.2.3 Operate actuator normally with supply pressure.
2.2.2.2.4 Check that the actuator is able to reach the fully closed position in case of fail close actuator or the fully open position
in case of fail open actuator. It is possible to check the fully stroked position by mean of visual position indicator or limit
switches if fitted. In case the actuator is not able to fully stroke, verify that the jackscrew has been totally retracted, rotating it
as described in first step.
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The safety lock is only available upon request. Please contact your local Flowserve Limitorque Representative for more information.
2.2.3 Operation – Not Enclosed Jackscrew Override Installed on Double-Acting LPC Actuator
Figure 7 – LPC Double-Acting with Not Enclosed Jackscrew Override
2.2.3.1 Manual Operation
a
CAUTION: prior to operating the actuator by mean of manual overrides, be sure to remove the pressure inside the cylinder and
that the cylinder has been vented to atmosphere through the venting ports. Ensure that all vent valves are in vent position. The
number of these valves varies as per the actuator and control schematic types.
To manually operate the override:
2.2.3.1.1 Remove the supply pressure inside the actuator’s cylinder, and vent the cylinder ports.
2.2.3.1.2 To open the valve, make sure that jackscrew installed on the scotch-yoke housing side is completely retracted by rotating the
relevant handwheel clockwise (CW). Then, operate the handwheel on the cylinder side in counterclockwise (CCW) direction.
2.2.3.1.3 To close the valve, make sure that jackscrew installed on the cylinder side is completely retracted by rotating the relevant
handwheel clockwise (CW). Now operate the handwheel on the scotch-yoke housing side counterclockwise (CCW) direction.