Fisher 4195 KB Series Instruction Manual page 45

4195KA, KB, and KC Series
W3451 / IL
27. Center the nozzle on the flapper as shown in fig-
ure 5–5 while squeezing the set point beam assembly
firmly against the relay nozzle tubing assembly. With
the nozzle centered on the flapper, tighten the ma-
chine screw (key 19). Ensure that the nozzle is still
centered on the flapper.
28. Insert the pivot of the adjustable set point pivot
assembly (key 17) into the hole in the set point beam
assembly (key 23).
29. Insert the screw, with washer (keys 19 and 20),
through the frame (key 3) and start it into the adjust-
able set point pivot assembly (key 17), but do not
tighten.
30. Squeeze the adjustable set point pivot assembly
against the set point beam assembly. Check to be
sure the nozzle is still centered on the flapper and
tighten the machine screw (key 19). If necessary, loos-
en both machine screws (key 19) to allow slightly mov-
ing the adjustable set point pivot assembly, set point
beam assembly and the relay nozzle tubing assembly
as a unit to center the nozzle on the flapper. After cen-
tering the nozzle, tighten the two machine screws.
31. Turn the proportional band adjustment knob to 5
percent DIRECT. Refer to figure 5–6 to locate the
locking nut on the adjustable set point pivot assembly.
Loosen the locking nut and back out the set screw
slightly so that the set point beam assembly falls un-
der its own weight when pivoted upward. Also, main-
tain a minimum side play between the adjustable set
point pivot assembly and the nozzle tubing assembly.
Tighten the locking nut.
32. At the frame manifold (key 135), tighten the nut
that secures the tubing from the relay nozzle tubing
assembly (key 18). Apply full supply pressure with the
5–12
LEVELING
SCREW
NUMBER 1
W4191 / IL
Figure 5–11. Link 2 Adjustment
nozzle capped (to obtain maximum output pressure)
and check for leaks. Remove supply pressure.
33. Install the set point beam bias spring (key 28) into
the frame bore and onto the spring seat on the set
point beam assembly, as shown in figure 5–3.
34. Attach link 3 to the set point beam shoe as shown
in figure 5–3.
The following procedure (steps 35
through 41) adjusts link 4 so it will al-
ways be in compression to eliminate
possible instability due to lost motion.
35. For controllers with reset and rate adjustments
(4195KB or 4195KC Series), remove the supply pres-
sure; then turn the reset adjustment to the CLOSED
(4195KB) or OFF (4195KC) position.
The controller output must be 0 psig (0 bar). To be
sure the controller output is 0 psig (0 bar), remove
supply pressure, set the reset adjustment to 0.01 min-
utes per repeat and wait 30 seconds; then, turn the
reset adjustment to the CLOSED (4195KB) or OFF
(4195KC) position.
36. Apply the correct supply pressure (refer to table
1–6) to the controller and provide an accurate means
of measuring the controller output pressure.
37. Adjust the proportional band to 5 percent RE-
VERSE and adjust the set point to the process scale
upper limit.
38. With link 1 disconnected, tape the process pointer
at the process scale lower limit. The output pressure
should be within 2 psig (0.14 bar) of the supply pres-
sure. If not, adjust flapper leveling screw 1 (the screw
CONNECTING TAB ON
FLAPPER ASSEMBLY
1/2 OF PIN
DIAMETER
Note