Logix
®
Digital Positioners FCD LGENIM0110-0 05/16
flowserve.com
40
Figure 40: Driver Module Barbed Fitting
27.8 Replacing a Driver Module
Assembly
The driver module assembly moves the spool valve by
means of a differential pressure across its diaphragm. Air
routed to the driver module from the regulator through a
flexible hose. A barbed fitting connects the flexible hose to
the driver module assembly. Wires from the driver module
assembly connect the Hall Effect sensor and the piezo
valve modulator to the main PCB assembly.
Removal
1
Remove the driver module cover (Figure 40), using a
flat bar or plate in the slot to turn the cover.
2
Remove the spool valve cover by removing the screw
and sliding the cover assembly backwards until the
tab is clear of the slot (Figure 38). 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.
3
Being careful not to lose the nylon washer, remove
the Phillips-head screw that attaches the driver
module to the main housing (Figure 39).
CAUTION:
Spool (extending from the driver module
assembly) is easily damaged. Use extreme caution when
handling spool and spool valve block. Do not handle the
spool by the machined portions of spool. The tolerances
between the block and spool are extremely tight.
Contamination in the block or the spool may cause the
spool to hang.
4
Remove the spool valve block by removing the two
Phillips-head screws and carefully sliding the block off
the spool (Figure 39).
5
Carefully remove the spool by sliding the end of the
spool out of the connection clip. Excessive force may
bend spool.
6
Remove the main cover.
7
Remove the plastic board cover by removing the
three retaining screws.
8
Disconnect the flexible tubing from the barbed fitting
at the driver.
9
Use the ¼” nutdriver to remove the barbed fitting from
the driver module assembly.
10
Unplug the two wiring connections that link the driver
module assembly to the main PCB assembly.
11
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 41). This will
allow the driver module to thread out without tangling
or cutting wires.
12
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.
13
Remove the barbed fitting from the side of the driver
module as shown in Figure 41 and hold the wires in
position by hand.
Installation
1
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 41 and hold the
wires in position by hand.
2
Gently insert the driver module into the driver module
compartment in the housing. Turn the driver module
clockwise to thread it into the housing. Continue
rotating the driver module until it bottoms out.
3
Once the driver module has bottomed out so that the
threads are fully engaged, rotate the driver module
counter clockwise until the flow on the driver module
and the flat on the house are aligned. This will align
the screw hole for the next step.
4
Verify that the nylon gasket is in the counter bore in
the driver module retaining screw hole as shown in
Figure 39.
5
Insert a driver-to-housing screw into the driver
housing through the counter bored hole in positioner
main housing. Tighten with a Phillip screwdriver.
6
Reach through the main compartment in the driver
module compartment of the positioner and install the
barbed fitting on the side of the driver module using
the ¼” 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
®
model. Orifices are
brass-colored, barbed fittings are silver-colored.
7
Reconnect the flexible tube coming from the regulator
to the barbed fitting.
8
Feed the driver module wires into the main chamber
of the housing ad connect them to the main PCB
Assembly.
9
Verify that the three O-rings are in the counterbores
on the machined platform where the spool valve block
is to be placed. (Figure 42).
10
Carefully slide the spool into the connecting clip on
the top of the driver module assembly.
11
Carefully slide the block over the spool, using the
machined surface of the house base as a register.
(Figure 39). Slide the block toward the driver module
until the two retaining holes line up with the threaded
holes in the base.
12
Install the two spool-valve screws and tighten
securely with a Phillips screwdriver (See Figure 39).
