Replacing The Loader Valve Plug And Valve Plug Spring - Fisher 4195 KB Series Instruction Manual

7. Position the range spring cup (key 284), range
spring (key 283), and the diaphragm assembly (key
281) on the upper loader assembly (key 282).
8. Position the ball (key 279), the tube (key 278), and
the ball seats (key 280) between the ears of the loader
assemblies (keys 282 and 274); position the dia-
phragm assembly (key 281) between the main halves
of the loader assemblies.
The tube (key 278) must be well seated
in the cups of the ball seats (key 280).
9. Bolt the loader assembly halves together using the
four screws (key 289).
CAUTION
Be sure that the supply and exhaust
seats of the loader are correctly aligned.
Misalignment will impair loader perfor-
mance.
10. Attach the tubing assembly (key 309).
11. Perform the Assembly portion of the Replacing
the Auto/Manual Station procedure.
Note
4195KA, KB, and KC Series
Replacing the Loader Valve Plug and
Valve Plug Spring
Refer to figure 5–31 for key number location.
1. Remove the controller assembly from the case by
performing steps 1 through 3 of the case and cover
replacement procedure.
2. Loosen the spring seat screw (key 275).
3. Remove the valve plug spring (key 276) and the
valve plug (key 277).
4. Inspect the parts and replace as necessary.
5. Install the valve plug spring and valve plug.
6. Tighten the spring seat screw.
7. Temporarily apply supply pressure and process
pressure and check for leaks.
8. 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 bot-
tom of the case. Hold the controller assembly in place
while tightening the nine mounting screws.
9. Mount the controller as described in the Installation
section.
10. Connect the external piping to the controller.
5–37