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4194S Controllers
July 2018
Figure 4-6. Proportional Band Adjustment Knob
Setting
TAB
HOLE
W3761
35. For direct acting controllers, adjust the proportional band knob to 5 percent direct acting. Adjust the set point
adjustment or with remote set point pressure to 5 percent of the process scale range.
WARNING
In step 36, do not exceed the operating limits of the controller (refer to table 1-3). Personal injury or equipment damage
may result from overpressure.
36. Slowly increase the process differential pressure from zero until the output pressure snaps to supply pressure. The
output pressure should snap to supply pressure within ±2 percent of set point.
37. If the output pressure snaps to supply pressure below 2 percent of set point, adjust flapper leveling screw number 3
clockwise (see figure 3-1 for location of screw). If the output pressure snaps to supply pressure above 2 percent of
set point, adjust flapper leveling screw number 3 counterclockwise.
38. Repeat steps 36 and 37 until the output pressure snaps within ±2 percent. If the tolerance cannot be obtained with
the flapper leveling screw, go to step 42.
39. Adjust the set point manually or with remote set point pressure to 95 percent of the process scale range.
40. If the output pressure is not 0 psi, decrease the process differential pressure until the output pressure snaps to zero.
Then slowly increase the process differential pressure until the output snaps to supply pressure. The output should
snap to supply pressure within ±2 percent of set point.
41. If the output pressure snaps to supply pressure within ±2 percent of set point, go to step 53. If the output pressure
does not snap to supply pressure within ±2 percent of set point, go to step 42.
42. If the output pressure snaps to supply pressure below 2 percent of set point, adjust the set point beam shoe
(key 29) slightly toward the center of the nozzle pivot. If the output snaps to supply pressure above 2 percent of set
point, adjust the set point beam shoe slightly away from the center of the pivot.
30
Figure 4-7. Nozzle‐Flapper Positioning
FLAPPER
W3449
Instruction Manual
D200158X012
NOZZLE
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