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25. Increase the process differential pressure until the
output pressure stabilizes at 3 psig (0.2 bar) for a 3 to
15 psig (0.2 to 1.0 bar) output or 6 psig (0.4 bar) for a
6 to 30 psig (0.4 to 2.0 bar) output. Record the pro-
cess differential pressure reading.
When the reset valve is at 0.01, the con-
troller is very sensitive to any process
pressure change. Only small process
pressure changes may be necessary.
26. Very slowly, increase the process differential pres-
sure until the output pressure stabilizes at 15 psig (1.0
bar) for a 3 to 15 psig (0.2 to 1.0 bar) output or 30 psig
(2.0 bar) for a 6 to 30 psig (0.4 to 2.0 bar) output. Re-
cord the process differential pressure reading.
27. If the difference between the recorded process
differential pressures in step 25 and 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 reset 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 the process scale span cannot be
achieved by adjusting the gain screw (key 34), loosen
the machine screw (key 35) attaching the reset bel-
lows 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 measure-
ment device, and the regulated differential 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 calibra-
tion procedure in section 3 or 4.
36. Mount the controller as described in the Installa-
tion section.
37. Connect external piping to the controller.
Note
4194A, B, and C Series
Replacing the Reset Restriction Valve
(4194B Series)
Refer to the 4194B Series portion of figure 5-21 for
key number locations.
1. Remove the controller assembly from the case by
performing steps 1 through 3 of the case and cover
replacement procedures.
2. Remove the reset valve tubing assembly (key 42)
from the reset restriction valve (key 54).
3. Remove the reset tubing assembly (key 43) from
the reset restriction valve.
4. For controllers with anti-reset windup (suffix letter
F), remove the relief valve tubing assembly (key 44)
from the reset restriction valve.
5. Remove the screw (key 162) that fastens the reset
restriction valve to the frame.
6. Install the replacement reset restriction valve and
secure it with the screw removed in step 5.
7. Install the reset valve tubing assembly (key 42), the
reset tubing assembly (key 43), and for controllers
with anti-reset windup, the relief valve tubing assembly
(key 44). Tighten all connections.
8. Set the reset adjustment to 0.01 minutes per re-
peat.
9. Apply the proper supply pressure to the controller,
cap the nozzle and check for leaks. Remove the sup-
ply pressure.
10. 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.
11. Perform the controller calibration procedures and,
if necessary, the remote set point calibration proce-
dure in section 4.
12. Mount the controller as described in the Installa-
tion section.
13. Connect external piping to the controller.
Replacing the Rate/Reset Valve Assembly
(4194C Series)
Read this entire procedure before re-
moving any parts. Refer to the 4194C
Series portion of figure 5-21 for key
number locations.
1. Remove the controller assembly from the case by
performing steps 1 through 3 of the case and cover
replacement procedures.
Note
5–15
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