Fisher 846 - Replacing the Module Final Assembly

Instruction Manual
D102005X012
846 Transducer
June 2017
35
3. Remove the module final assembly from the module cover. To accomplish this, hold the cover steady, and push the
module final assembly in the direction of the module cover indicating boss. At the same time, lift the opposite foot
of the module final assembly out of the cover slot, as shown in figure 17.
Figure 16. Alignment Key Above Module Cover
Indicating Boss
MODULE
ALIGNMENT
KEY
INDICATING
BOSS
A6649
Figure 17. Removing the Module Final Assembly
from the Module Cover
A6650
Replacing the Module Final Assembly
Use the following procedure to attach the module cover and replace the module final assembly:
1. Ensure that the electronic circuit board and the pilot actuator assembly provide the desired action (direct or
reverse). See the Electronic Circuit Board and Pilot/actuator Assembly Action descriptions later in this section.
2. Ensure that the slip ring is in place around the feet of the module final assembly. The module cover O‐ring should be
lightly lubricated with silicone grease and placed in the O‐ring gland. The stroke port screen should be clean and in
place.
Note
The module cover O‐ring must be in the O‐ring gland, not down on the threads of the cover. This will ensure proper sealing of the
pilot pressure area.
3. Position the retaining clips in the module cover so they are ready to accept the feet of the module final assembly.
Ensure the leaves on the retaining clips are facing up. Figure 15 shows the correct orientation.
4. Insert one of the module feet into a cover slot, and push on the module final assembly to compress the retaining
clip. Insert the opposite foot into the opposite cover slot, and rotate the module 90 degrees in the module cover to
secure it in place.
5. Ensure that the three module O‐rings are in the O‐ring glands and are lightly lubricated with silicone grease. Inspect
the O‐rings to ensure that they are not twisted or stretched.
6. Apply lubricant to module cover threads for ease of assembly.
7. Prepare to insert the module into the housing. Align the V‐groove located on the module final assembly with the
indicating mark located on the nameplate. This positions the alignment key with the key slot. Figure 15 shows the
location of the V‐groove and the indicating mark.
8. Insert the module, engage the module cover threads, and screw on the module cover. The module final assembly
will automatically engage the electrical feedthroughs and span and zero screws.