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1
END BUSHING
ADJUSTMENT ARM
1
END BUSHING
NOTE:
BEFORE TIGHTENING THE DRIVE FLEXURE MOUNTING SCREWS,
1
POSITION THE SHAFT SO THE END BUSHINGS "FLOAT" IN THE BEARINGS.
26A9784-E
A5682 / IL
Figure 5-18. Cutaway of Long Pivot Clevis Assembly
arm to the same length as the arm on the pivot as-
sembly being replaced.
7. Attach the replacement pivot clevis assembly to the
mounting plate with the two mounting screws (key
102).
8. Loosely connect the drive flexure to the pivot ad-
justment arm of the new pivot clevis assembly.
See figure 5-18. The adjustment arm of the long pivot
clevis assembly is connected to a shaft that turns on
bushings at each end of the shaft. In the next step,
position the shaft so that both bushings ''float'' inside
the bearings and do not rest against the end of either
bearing.
9. Apply 75 percent of the capsular element range to
the capsule. The drive flexure should be straight and
horizontal. Before tightening the drive flexure cap
screws (key 12), hold the pivot shaft in the middle of
the bushing end play. Be sure neither bushing is rest-
ing against the inside end of either bearing. Tighten
the drive flexure cap screws to hold the pivot shaft in
position. Adjust the length of the pivot adjustment arm
as needed until the drive flexure is horizontal. Take
care not to kink or twist the flexure when tightening the
screws.
10. Connect the left-hand end of link 5 (key 88) to the
pivot adjustment arm in the hole position noted in step
3.
11. Replace the tie bar (key 97).
BEARING
12. Perform the capsular element maintenance cal-
ibration procedures in this section. Perform the con-
troller calibration procedures and, if necessary, per-
form the appropriate remote set point calibration
procedure in section 3 or 4.
Replacing the Short Pivot Assembly
Refer to figure 5-23 for capsular element key number
locations.
SHAFT
1. Remove the process pressure from the controller.
2. Note the hole positions of links 1 and 5 (keys 88
and 90) and disconnect the links from the short pivot
clevis assembly (key 89). Also, note the screw position
BEARING
of the linearity adjustment for later reference.
3. Remove the two machine screws (key 102) attach-
ing the short pivot clevis assembly (key 89) to the
mounting plate (key 77), and remove the pivot clevis
assembly.
4. Set the linearity adjustment screw on the replace-
ment pivot clevis assembly to approximately the same
location as noted in step 2. The linearity adjustment
screw location is shown figure 5-17.
5. Position the replacement short pivot clevis assem-
bly on the mounting plate, and attach it with the two
mounting screws.
6. Attach links 1 and 5 (keys 88 and 90) in the same
hole position as noted in step 2.
7. Perform the capsular element maintenance calibra-
tion procedures in this section. Perform the controller
calibration procedures and, if necessary, the appropri-
ate remote set point calibration procedure in section 3
or 4.
Replacing the Process Drive Flexure
Refer to figure 5-23 for the capsular element key num-
ber locations.
1. Set the process pressure to 75 percent of the cap-
sular element span.
2. Remove the tie bar (key 97) from the capsular ele-
ment assembly by removing the mounting screws (key
103).
3. Using an Allen wrench, remove the cap screws and
washers (keys 12 and 13) to disconnect the drive flex-
ure (key 79) from the drive bracket assembly (key 84)
and from the pivot adjustment arm of the long pivot
clevis assembly (key 78). Remove the drive flexure.
4. Loosely connect the replacement drive flexure,
making sure it is straight and horizontal.
4194A, B, and C Series
5–21
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