Replacing Pivot Assembly B (Key 115); Replacing The Drive Flexure - Emerson Fisher 4195KA Instruction Manual

Instruction Manual
D200160X012
10. Apply remote set point pressure equal to 50 percent of the remote set point input range.
Note
See figure 6‐20. The adjustment arm of the remote set point pivot assembly A turns on a bushing at each end of the shaft
supporting the adjustment arm. In the next step, position the shaft so both bushings "float" inside the bearings and do not rest
against the end of either bearing.
11. Connect the drive flexure (key 79) to the arm on the replacement pivot assembly, making sure it stays straight and
vertical. Adjust the length of the pivot arm, if necessary, until the flexure is vertical. Before tightening the drive
flexure screws, hold the pivot assembly shaft in the middle of the bushing end play. Be sure neither bushing is
resting against the inside end of either bearing. Tighten the drive flexure screws to hold pivot assembly A in this
position. Do not bend or twist the flexure when tightening the screws.
12. Decrease the remote set point pressure to 0 bar (0 psig).
13. Connect the end of link A (key 116) to the pivot lever arm in the same holes noted in step 3.
14. Replace the tie bar (key 106).
15. Perform the remote set point maintenance calibration procedure. Perform the appropriate process indicator zero
and span calibration and flapper alignment procedures in Section 3, 4, or 5.

Replacing Pivot Assembly B (Key 115)

1. Decrease the remote set point pressure to 0 bar (0 psig).
2. Note the holes where links A and B are connected. Disconnect links A and B (keys 116 and 126) from the arms of
pivot assembly B (key 115).
3. Remove the two screws (key 102) that attach pivot assembly B to the mounting plate (key 111). Remove the pivot
assembly.
4. Loosen the linearity adjustment screw on the replacement pivot assembly and set it in the same position as the
adjustment on the original pivot assembly. Tighten the screw.
5. Set the replacement pivot assembly on the mounting plate, and attach it with the two machine screws.
6. Attach links A and B (keys 116 and 126) to the arms of the replacement pivot assembly in the same holes noted in
step 2.
7. Perform the remote set point maintenance calibration procedure. Perform the appropriate process indicator zero
and span calibration and flapper alignment procedures in Section 3, 4, or 5.

Replacing the Drive Flexure

1. Using an Allen wrench, remove the cap screws (key 12) and washers (key 13) to disconnect the drive flexure (key
79) from the drive bracket (key 121) and from the adjustment arm of pivot assembly A. Remove the drive flexure.
2. Set the remote set point pressure to 50 percent of the remote set point input range.
Note
See figure 6‐20. The adjustment arm of the remote set point pivot assembly A turns on a bushing at each end of the shaft
supporting the adjustment arm. In the next step, position the shaft so both bushings "float" inside the bearings and do not rest
against the end of either bearing.
3. Connect the new drive flexure making sure it stays straight and vertical. Adjust the length of the pivot arm, if
necessary, until the drive flexure is straight. Before tightening the drive flexure screws, hold the pivot assembly A
4195K Controllers
July 2018
95