Fisher 8580 Instruction Manual page 15

Instruction Manual
D103300X012
Disassembly
1. Remove the seal ring assembly according to steps 3 and 4 of the Replacing Seal Ring section on page 12 of this
manual.
2. Remove hex nuts, blind flange, gasket, spacer (if present), follower spring seats, and follower spring (keys 19, 17,
16, 15, 9, and 12).
3. Clean the gasket surfaces on the blind flange (key 17) and on the end of the valve body (key 1).
4. Rotate the disk (key 3) to the fully open position.
5. Refer to figure 7 and determine the location of the smaller end of the taper pins (key 8). Drive out the taper pins and
expansion pins (key 7) towards the larger end.
WARNING
Once the shafts have been removed in the following step, the disk may fall from the valve body. To avoid personal injury
and disk damage, support the disk to prevent it from falling as the shafts are being removed.
6. For valves with a two-piece, split shaft, pull the follower shaft (key 11) out through the outboard end of the valve
body. If the follower shaft cannot be pulled free, the end of the follower shaft is internally threaded (see table 6) for
screwing in a bolt or stud to aid in pulling the follower shaft.
7. Pull the drive shaft (key 10) out through the actuator end of the valve body and remove the anti‐blowout ring (key
40) from the drive shaft.
8. Remove the disk (key 3) from the valve body.
9. Remove the packing (key 24, figure 5) and the packing box ring (key 23, figure 5).
10. If either of the bearings (key 6) require replacement, remove them.
11. Clean the packing box and [metal packing box parts].
Assembly
WARNING
Do not lubricate bearings that will be used for oxygen service, or where the lubrication is incompatible with the process
media. Any use of lubricant can lead to the sudden explosion of media due to the oil/oxygen mixture, causing personal
injury or property damage.
CAUTION
To avoid possible product damage, ensure the bearing tabs are oriented correctly when installing in the following
procedure. See figure 6 for proper orientation of the bearings.
1. If new bearings (key 6) are required, install and orient them in the valve body, as shown in figure 6. Ensure the
bearings are fully seated, contacting the inside diameter of the valve body.
2. Insert the disk into the valve body as shown in figure 7, ensuring the "T" stamped on the disk hub is oriented toward
the actuator end of the valve body.
3. Install the drive shaft (key 10) through the valve body into the disk. The disk/shaft connection utilizes taper and
expansion pins. The hole for the drive shaft connection is slightly off‐center to prevent the drive shaft from being
8580 Valve
April 2020
15