Instruction Manual
D200156X012
4194HA, HB, HC Controllers
July 2018
50
Figure 5‐8. Link Number 3 Adjustment
LINK 3 ADJUSTMENT
LINK 2 DISCONNECT
W4192‐1
5. Check the set point beam bias spring (key 28). Is it correctly located in the frame bore and spring seat on the set
point beam assembly as shown in figure 5‐9?
6. Move the set point adjustment indicator to 50 percent of scale range.
7. Adjust the process differential pressure until the process indicator is at 50 percent of the scale range.
8. Adjust the proportional band to 5 percent direct action. Turn the flapper leveling screw number 3 until the nozzle
just touches the flapper.
Note
Flapper leveling screws 1 and 3 should protrude the same distance from the clinch nuts. See figure 5‐7.
9. Adjust the proportional band to 5 percent REVERSE (reverse action). Turn flapper leveling screw number 1 until the
nozzle just touches the flapper.
If flapper leveling screw 1 protrudes farther than flapper leveling screw 3, turn the adjusting screw in link 3
counterclockwise
. If flapper leveling screw 3 protrudes farther than flapper leveling screw 1, turn the adjusting
screw in link 3
clockwise
.
11. Perform the pressurized maintenance calibration and flapper alignment procedures.
Link 4
1. Remove the two screws (key 6) and lift off the proportional band cover (key 36).
2. Refer to figure 5‐5 for location of link 4. Note where the link is connected. Disconnect the link from bellows bracket
assembly (key 31) and the input feedback assembly (key 11).
3. Connect the replacement link to the input feedback assembly so the two adjusting screws on the link are nearest to
the feedback bellows bracket. The screw heads should face the bottom of the controller as shown in figure 5‐12 and
be positioned as noted in step 2.