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tube mounting screws (key 384, figure 5–25). Also,
loosen the two screws (keys 379 and 380, figure 5–25)
holding the process tubing retainer.
16. Slide the Bourdon tube up or down and tighten the
four screws loosened in step 15. Several trys may be
required to determine the direction in which to move
the Bourdon tube to obtain the required accuracy. Re-
turn to step 5.
17. Adjust the process pointer to within 1 percent of
the mid-scale mark by loosening the zero adjustment
locking screw and adjusting the zero adjustment
screw. Tighten the zero adjustment locking screw.
This distributes the error over the entire process scale
and keeps all points within 1 percent of the process
scale span.
18. Adjust the process pressure to the lower and up-
per limits of the process scale span to make sure the
process pointer is still within 1 percent of the lower
and upper scale limits.
19. Perform the flapper alignment procedure and, if
necessary, the appropriate remote set point calibration
procedure in section 3 or 4.
Capsular Element Controller
Maintenance and Calibration
Replacing the Capsular Element
Assembly
Refer to figure 5–28 for key number locations, unless
noted otherwise.
1. Remove process pressure from the controller.
2. Note the hole location and disconnect link 1 (key
90) from the process pointer.
3. Disconnect the process pressure connection union
(key 93) from the pedestal assembly (key 81). Use two
5/16-inch hex wrenches.
4. Remove the four machine screws (key 127 in figure
5–26) that attach the capsular element assembly to
the indicator assembly (key 101 in figure 5–26).
CAUTION
In the following step, do not lift out the
capsular element assembly by holding
the capsular element or linkages. These
parts may be damaged.
5. Lift out the capsular element assembly by holding
the tie bar (key 97), mounting plate (key 77), travel
stop (key 83), or pedestal assembly (key 81).
4195KA, KB, and KC Series
6. Position the replacement capsular element assem-
bly over the mounting screw holes. Install and tighten
the mounting screws (key 127 in figure 5–26).
7. Reconnect link 1 (key 90) to the process pointer in
the same hole noted in step 2.
8. Reconnect the process pressure connection union
(key 93).
9. Apply process pressure to the controller and check
for leaks.
10. Perform the capsular element maintenance cal-
ibration procedure in this section. Perform the control-
ler calibration procedures and, if necessary, the ap-
propriate remote set point calibration procedure in
section 3 or 4.
Replacing Capsular Element Parts
Refer to figure 5–28 for capsular element key number
locations. Refer to figure 5–19 for adjustment locations
and refer to figure 5–27 for indicator assembly (without
process sensing element) part locations.
Replacing the Long Pivot Assembly
1. Remove process pressure from the controller.
2. Remove the tie bar (key 97) from the capsular ele-
ment assembly by removing the mounting screws (key
103).
3. Note the hole position of link 5 (key 88) and discon-
nect the link from the pivot adjustment arm on the long
pivot clevis assembly (key 78).
4. Using an Allen wrench, remove the cap screw and
washer (keys 12 and 13) that attach the drive flexure
(key 79) to the pivot adjustment arm of the long pivot
clevis assembly. Take care not to bend or kink the
drive flexure.
5. Remove the two screws (key 102) attaching the
long pivot clevis assembly to the mounting plate (key
77).
6. Loosen the screw on the pivot adjustment arm of
the replacement pivot clevis assembly, and adjust the
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 on the new pivot clevis assembly.
See figure 5–20. 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
5–23
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