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4194S Controllers
July 2018
4. Adjust the process differential pressure to 0 psid. Adjust the proportional band to 5 percent direct acting, and move
the set point manually or with the remote set point pressure to 100 percent of process scale range. Controller
output should be 0 psig.
5. With zero pressure in the feedback bellows, loosen the two adjustment screws on the link. Connect the free end of
the link to the bellows bracket assembly, and allow the link to find its free length.
6. Tighten the two adjusting screws on the link.
7. Refer to the Maintenance Calibration and the Flapper Alignment procedure.
8. Replace the proportional band indicator (key 36), and tighten two screws (key 6).
Link Number 5
1. Refer to figure 5-2 for key number locations.
2. Note where the link is connected. Disconnect both ends of link 5 (key 88) from the lever arms of the two pivot
assemblies.
3. Loosen the adjustment screw on the replacement link, and adjust the length to match the original link. Tighten the
adjustment screw.
4. Attach the replacement link to the two lever arms in the same location as noted in step 2.
5. Refer to the Maintenance Calibration procedure.
Long Pivot Assembly
1. Remove the process pressure from the controller.
2. Remove the tie bar (key 97).
3. Note where the link is connected. Disconnect link 5 (key 88) from the lever arm on the pivot assembly (key 78).
CAUTION
Avoid bending or kinking the drive flexure. Bending or kinking the drive flexure can result in product damage, as well as
impaired performance.
4. Disconnect the drive flexure (key 79) from the adjustment arm of the pivot assembly. Take care not to bend or kink
the drive flexure.
5. Remove the two screws (key 102) attaching the pivot assembly to the mounting plate (key 77).
6. Loosen the screw on the adjustment arm of the replacement pivot assembly, and adjust the arm to the same length
as the arm on the pivot assembly being replaced.
7. Attach the new pivot assembly to the mounting plate with the two mounting screws.
8. Loosely connect the drive flexure to the arm on the new pivot assembly.
9. Apply 75 percent of the input differential pressure range to the capsule. The flexure should be straight and
horizontal. Before tightening the screws, set the pivot in the middle of the bushing end play. Tighten the flexure to
hold the pivot in that position. Adjust the length of the adjustable pivot arm as needed until the flexure is straight.
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 lever arm in the position noted in step 3.
11. Replace the tie bar (key 97).
12. Refer to the Maintenance Calibration procedure.
Short Pivot Assembly
1. Remove the process pressure from the controller.
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Instruction Manual
D200158X012
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