Flowserve 3400MD Digital Positioner - Manual (Page 38)

Logix 3400MD Digital Positioner FCD LGENIM3404-08-AQ –5/15
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4. Remove the spool valve cover by removing the screw and sliding
the cover assembly backwards until the tab is clear of the slot
(Figure 13). The sheet metal cap, hydrophobic filter, and O-ring
should be removed with the spool valve cover. It is not necessary
to take these parts out of the spool valve cover.
5. Being careful not to lose the nylon washer, remove the Phillips-
head screw that attaches the driver module to the main housing
(Figure 14).
6. Remove the spool valve block by removing the two Phillips-head
screws and carefully sliding the block off the spool (Figure 14).
7. Carefully remove the spool by sliding the end of the spool out of
the connection clip. Excessive force may bend spool.
8. Remove the main cover.
9. Remove the plastic board cover by removing the three retaining
screws (see Figure 16).
10. Disconnect the flexible tubing from the barbed fitting at the driver
module assembly (see Figure 15).
11. Use the 1/4” nutdriver to remove the barbed fitting from the driver
module assembly.
12. Unplug the two wiring connections that link the driver module
assembly to the main PCB assembly.
13. Feed the two wires on the driver module back into the driver
module compartment so that they stick out the driver module
opening (see Figure 12). This will allow the driver module to
thread out without tangling or cutting the wires.
14. Grasp the base of the driver module and turn it counterclockwise
to remove. After it is threaded out, carefully retract the driver
module from the housing.
15. Remove the barbed fitting from the side of the new driver module
using the 1/4” nutdriver.
16. Verify that the O-ring is in place on the top of the new driver
module. Lay the wires back along the side of the driver module as
shown in Figure 12 and hold the wires in position by hand.
17. Gently insert the driver module into the driver module compart-
ment in the housing. Turn the driver module clockwise to thread
it into the housing. Continue rotating the driver module until it
bottoms out.
18. Once the driver module has bottomed out so that the threads
are fully engaged, rotate the driver module counter clockwise
until the flat on the driver module and the flat on the housing are
aligned. This will align the screw hole for the next step.
19. Verify that the nylon gasket is in the counter bore in the driver
module retaining screw hole as shown in Figure 14.
20. Insert a driver-to-housing screw into the driver housing through
the counterbored hole in positioner main housing. Tighten with a
Phillips screwdriver.
21. Reach through the main compartment into the driver module
compartment of the positioner and install the barbed fitting on the
side of the driver module using the 1/4” nutdriver.
NOTE: Do not mix the barbed fitting with those from older Logix
positioners. Older models contain orifices that will not work in the
Logix 3400MD model. Orifices are brass-colored, barbed fittings
are silver-colored.
22. Reconnect the flexible tube coming from the regulator to the
barbed fitting.
23. Feed the driver module wires into the main chamber of the
housing, and connect them to the main PCB Assembly.
24. Verify that the three O-rings are in the counterbores on the
machined platform where the spool valve block is to be placed
(Figure 22).
25. Carefully slide the spool into the connecting clip on the top of the
driver module assembly.
26. Carefully slide the block over the spool, using the machined
surface of the housing base as a register (Figure 14). Slide the
block toward the driver module until the two retaining holes line
up with the threaded holes in the base.
Figure 16: Driver Module Barbed Fitting