Flowserve 3400MD Digital Positioner - Manual (Page 41)

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Logix 3400MD Digital Positioner FCD LGENIM3404-08-AQ – 5/15
flowserve.com
6. Position the barbed tee between the internal regulator and the
driver module by connecting the 1⁄16” flexible tubing, found in
the positioner, to one side of the barbed tee. Using one of the new
flexible tubing pieces, connect the barbed tee to the barbed fitting
on the side of the driver module. Connect the remaining port on
the barbed tee to a 0 to 30 psi pressure gauge.
7. Reconnect the air supply to the positioner and read the internal
regulator pressure on the 0 to 30 psig gauge. The internal
pressure should be set to 17.4 ±0.2 psig. If adjustment is needed,
loosen the set screw retaining nut on the top of the regulator
using the 3⁄8”open-end wrench. Then adjust the regulator pres-
sure by turning the set screw on the top of the regulator with the
3⁄32” Allen wrench.
8. Once the regulator pressure is set, tighten the set screw retaining
nut on the top of the regulator, remove the air supply to the
positioner, remove the barbed tee, and reconnect the flexible
tubing from the regulator to the barbed fitting on the side of the
driver module.
9. Install the plastic board cover. Insert the three retaining screws
through the plastic cover into the threaded boss and tighten
evenly, using a Phillips screwdriver. Do not overtighten (see
Figure 16).
10. Reinstall all covers.
8.4 Spool Valve
The spool valve routes the supply air to one side of the actuator while
venting the opposite side (see Figure 1). The position of the spool
valve is controlled by the driver module.
Replacing the Spool Valve
To replace the spool valve, refer to Figures 12, 14 and 21 and proceed
as outlined below. The following tools are required:
• Phillips screwdriver
1. Make sure the valve is bypassed or in a safe condition.
2. Disconnect the power and air supply to the unit.
3. Remove the spool valve cover by removing the screw and sliding
the cover assembly backwards until the tab is clear of the slot.
It is not necessary to remove the sheet metal cap, hydrophobic
filter, or O-ring from this assembly (Figure 18).
c DANGER: The 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 on 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 14).
5. Carefully remove spool by sliding end of spool out of connecting
clip. Excessive force may bend the spool.
6. Verify that the three O-rings are in the counterbores on the
machined platform where the new spool valve block is to be
placed (Figure 22).
7. Carefully slide the spool into the connecting clip of the driver
module assembly.
8. 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.
9. Install two spool valve screws and tighten securely with a Phillips
screwdriver (see Figure 14).
10. Slide the spool valve cover assembly over the spool valve until the
tang engages into the housing slot. Install the spool valve cover
screw and tighten securely (see Figure 13).
11. Reconnect power and air supply to the positioner and perform a
stroke calibration.
8.5 Spool Valve Cover
The spool valve cover incorporates a hydrophobic filter element in a
two-piece cover. This protects the spool valve chamber from dirt and
moisture and provides a low back pressure vent for exhaust air from
the spool valve.
Replacing Filter in Spool Valve Cover
To replace the filter in the spool valve cover, refer to Figures 13 and
18 and proceed as outlined below. The following tools are required:
• Phillips screwdriver
1. Remove the spool cover by removing the screw and sliding the
cover assembly backwards until the tab is clear of the slot. The
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.