Flowserve Logix 3400MD User Instructions page 40

Figure 19: Stem Position Sensor Orientation
sheet metal cover may be removed and cleaned with a brush or by
blowing out with compressed air (Figure 13).
2. Remove the O-ring from around the hydrophobic filter element and
set aside (Figure 18).
3. Remove the molded filter element by pulling it straight out of the
chamber cover vent piece.
4. Install O-ring into base of chamber cover vent piece as shown in
Figure 18.
5. Place new molded filter element into the chamber cover vent piece.
This filter element provides part of the track to secure the O-ring
installed in the last step.
6. Place spool valve shroud onto spool valve cover.
7. Place the spool valve cover assembly in place by setting it on the
ramp and sliding it until the tab seats in the slot (Figures 13 and 18)
and secure with a 8-32 screw.
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Logix 3400MD Digital Positioner FCD LGENIM3404-00 – 9/09
Figure 18: Spool Valve Cover Assembly
8.6 Stem Position Sensor
The position feedback assembly transmits valve positions information
to the processor. This is accomplished by means of a rotary position
sensor that connects to the valve stem through a feedback linkage. To
provide for accurate tracking of the pin in the slot, the follower arm is
biased against one side of the slot with a rotary spring. This spring also