Replacing The Reset Restriction Valve (4195Kb Controllers) - Emerson Fisher 4195KA Instruction Manual

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Instruction manual (108 pages)

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Table of Contents

4195K Controllers

July 2018

24. Adjust the reset adjustment to 0.01 minutes per repeat. For a 4195KC controller, set the rate adjustment to OFF.

25. Increase the process pressure until the output pressure stabilizes at 0.2 bar (3 psig) for a 0.2 to 1.0 bar (3 to 15 psig)

output or 0.4 bar (6 psig) for a 0.4 to 2.0 bar (6 to 30 psig) output. Record the process pressure reading.

Note

When the reset valve is at 0.01, the controller is very sensitive to any process pressure change. Only small process pressure

changes may be necessary.

26. Very slowly increase the process pressure until the output pressure stabilizes at 1.0 bar (15 psig) for a 0.2 to 1.0 bar

(3 to 15 psig) output or 2.0 bar (30 psig) for a 0.4 to 2.0 bar (6 to 30 psig) output. Record the process pressure

reading.

27. If the difference between the recorded process pressure in step 25 and the process pressure in step 26 is larger than

±1 percent of the process scale span, proceed with step 28. If the difference is less than ±1 percent, go to step 33.

28. Loosen the proportional bellows screw (key 35).

29. If the reading recorded in step 26 is greater than in step 25, adjust the reset gain screw (key 34) one‐half turn in

(clockwise). If the reading recorded in step 26 is less than in step 25, adjust the gain screw (key 34) one‐half turn out

(counterclockwise).

30. Tighten the proportional bellows screw (key 35).

31. Repeat steps 25 through 30 until the difference is less than ±1 percent of the process scale span.

32. If ±1 percent of process scale span cannot be achieved by adjusting the gain screw (key 34), loosen the machine

screw (key 35) attaching the reset bellows and slide it to the left if the reading in step 26 is greater than in step 25,

or to the right if the reading in step 26 is less than in step 25. Tighten the screw and repeat steps 25 through 31.

33. Remove the supply pressure, the output measurement device, and the regulated process pressure source.

34. Position the controller assembly in the case and start, but do not tighten the nine mounting screws. Slide the

controller assembly down to assure an O‐ring seal at the pressure connections along the bottom of the case. Hold

the controller assembly in place while tightening the nine mounting screws.

35. Perform the controller calibration procedures and, if necessary, the appropriate remote set point calibration

procedure in Section 3, 4, or 5.

36. Mount the controller as described in the Installation section.

37. Connect the external piping to the controller.