Replacing The Flapper Assembly And Flapper Flexure Pivot Assembly - Fisher 4195 KB Series Instruction Manual

4195KA, KB, and KC Series
W4199 / IL
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.
46. Perform the controller calibration procedures and,
if necessary, the appropriate remote set point calibra-
tion procedure in section 3 or 4.
47. Mount the controller as described in the Installa-
tion section.
48. Connect the external piping to the controller.
Replacing the Flapper Assembly and
Flapper Flexure Pivot Assembly
1. Remove the controller assembly from the case by
performing steps 1 through 3 of the case and cover
replacement procedure.
2. Remove the two screws (key 6) and lift off the pro-
portional band indicator cover (key 36).
3. Disconnect link 3 from the set point beam shoe,
part of the set point beam assembly (key 23). Refer to
figure 5–3 for the link location.
4. Remove the set point beam bias spring (key 28).
Refer to figure 5–3 for the spring location.
5. Remove the screw and washer (keys 19 and 20)
that hold the adjustable set point pivot assembly (key
17) to the frame.
5–10
Figure 5–7. Bellows Assembly and Proportional Band Adjustment
(Process Scale and Proportional Band Indicator Cover Removed)
PROPORTIONAL
BELLOWS
BELLOWS
BRACKET
(KEY 31)
ADJUSTABLE
SET POINT PIVOT
ASSEMBLY (KEY 17)
SCREW AND
WASHER
(KEYS 19 AND 20)
LINK 4
LINK 2
6. Remove the adjustable set point pivot assembly
(key 17).
7. Unscrew the nut that secures the relay nozzle tub-
ing assembly (key 18) to the frame manifold (key 135).
Refer to figure 5–3.
8. While holding the proportional band adjustment-
knob, remove the screw and washer (keys 19 and 20)
that hold the relay nozzle tubing assembly (key 18) to
the frame.
9. Remove the proportional band adjustment knob,
relay nozzle tubing assembly, and the set point beam
assembly from the controller.
10. Disconnect link 2 from the flapper assembly (key
11). Refer to figure 5–7 for the link location.
11. Disconnect link 4 from the bellows bracket (key
31). Refer to figure 5–7 for the link location.
12. Remove the two cap screws (key 12) from the
flexure pivot assembly (key 9). See figure 5–8 for
screw location.
13. Remove the flapper assembly and link 4 as shown
in figure 5–9.
14. Remove the four machine screws (key 10), shown
in figure 5–9, that hold the flexure pivot assembly to
the frame.
15. Remove the flexure pivot assembly (key 9).
16. Install the replacement flexure pivot assembly
with the four screws (key 10). Do not tighten the
screws.