Flowserve Mechanical and Hydraulic - Manual (Page 7)

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Mechanical and Hydraulic Overrides FCD LFENIM0004-00-AQ – 05/15
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Mechanical Manual Overrides
Mechanical Manual Overrides on LFPS heavy duty and compact actuators provide an economical and durable method for manually
operating the actuators. LFPS Mechanical Overrides are designed in accordance with EN 12570 Standard. The manual force to operate
the actuator shall not exceed the values stated in EN 12570, when measured at the outermost point of the handwheel.
LFPS Mechanical Manual Overrides are available in the following versions:
• Enclosed Jackscrew (-JS)
• Not Enclosed Jackscrew (-JL)
• Bevel gear (-BG)
They are designed and standardized depending on the Actuators series, however special versions are available upon request.
a CAUTION: prior to operating an actuator by means 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 vent valves varies by actuator and control schematic types.
2.1 Enclosed Jackscrew Manual Override (-JS)
The Enclosed Jackscrew is a direct operating handwheel, which means that a rotating screw can be fitted either on the cylinder side
(single-acting actuators LPS series) or on the scotch-yoke housing (double-acting actuators LPS series). The rotation of the hand-
wheel in clockwise (CW) or counterclockwise (CCW) directions will cause the consequent rotation of the scotch-yoke mechanism and
the stem of the valve which the actuator is fitted on.
The Enclosed Jackscrew has a totally enclosed and protected design, with no externally exposed threads or moving parts, which
makes this manual override suitable for severe and saline environmental conditions.
Figure 1 – Enclosed Jackscrew Manual Override for Double-Acting Actuators (left) and Single-Acting Actuators (right)
The Enclosed Jackscrew option is available for the LPS-15 and LPS-20 single-acting and double-acting versions.
Travel Stop
Seal Nut
Travel Stop
Seal Nut