Nps - Fisher A41 Instruction Manual

Installing the Hollow Pin and Taper Pin
4. Place the valve body on a flat working surface with the slot for the seal ring facing up. Block the valve body high
enough to allow the disc to be rotated into the open position as shown in figure 11.
Note
Make sure that the taper pins and hollow pins are free of particulate matter before continuing.
5. Rotate the disc to the open position. Locate the disc position mark on the end of the drive shaft. Rotate the shaft
until it is in the appropriate disc position as shown in figure 7.
6. Line up both holes in the disc hub with the holes in the drive shaft (key 8). (Note: The hole in the drive shaft is offset
to prevent the shaft from being installed in the wrong position. Be sure the hole in the shaft is lined up with the hole
in the disc hub.)
7. Insert the hollow pins (key 9), into the disc hub as shown in figure 11.
Using the tool shown in figure 11, tap the hollow pin down into the disc hub and shaft until the pin bottoms on the
stop in the disc.
8. Insert the taper pins (key 10) into the hollow pins. Using a flat end punch, drive the taper pins into the hollow pins
until solid contact is felt. Anchor the pins in place by staking them with a center-punch and hammer. The disc and
shaft should rotate smoothly.
9. Install the seal ring assembly using the appropriate instructions in the Seal Ring Maintenance procedures.
10. Install the packing parts using the appropriate instructions provided in the Packing Maintenance procedures. Refer
to the Actuator Mounting and Adjustment procedures before installing the valve in the pipeline.
Disc, Shaft Assembly and Bearing Maintenance for NPS 2
This procedure is to be performed to replace the valve disc, shaft, and taper pin assembly if the disc does not rotate in
response to rotation of the actuator end of the valve shaft. Unless otherwise indicated, part key numbers are shown in
figure 13.
Disassembly
1. Remove the seal ring according to steps 1 through 5 of the Replacing Seal Ring section.
CAUTION
Use a wheel puller to separate actuator parts from the valve shaft. Driving the parts off the valve shaft could move the valve
bearings and disc away from the centered position, damaging the disc and valve.
2. Remove the cap screws and if used the hex nuts. Remove the clamp if the strap is used. Remove the actuator from
the valve body while referring to the separate actuator instruction manual for assistance.
3. Rotate the disc (key 3) to the fully open position.
4. Locate the half of the disc that has two C markings cast into it as shown in figure 7. Drive the two taper pins (key 3C)
out toward the C-marked side of the disc. Attempting to drive the taper pins in the opposite direction only tightens
the pins.
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