Instruction Manual
D104709X012
8540 Valve
September 2021
15
3. Turn the disk into and out of the seal ring several times, to help break in the seal and reduce actuator torque
requirements during adjustment.
4. If replacing the packing, remove all packing parts from the valve body. Upon re‐assembly of the valve, refer to the
Packing Maintenance procedures to replace the packing.
Disk, Drive Shaft, and Bearing Maintenance
This procedure is to be performed when replacing the valve disk, drive shaft, taper pins, hollow pins, and bearings due
to wear or damage to one or more component parts.
Key numbers are shown in figure 12 unless otherwise noted.
Disassembly
1. Isolate control valve from line pressure, relieve pressure and drain process fluid, then remove control valve
assembly from the pipeline as described in Seal Ring Maintenance section.
2. Loosen the packing flange nuts (key 101). This allows the drive shaft (key 8) to turn without the friction caused by
the packing.
3. Remove the actuator using the steps provided in the Packing Maintenance section and separate actuator
instruction manuals, and remove the seal ring using the steps provided in the seal ring maintenance procedures
above.
4. Place the valve on a flat working surface with the seal ring slot facing down.
5. Use blocks to raise the valve body high enough to allow the disk to be rotated to the fully open position (see figure
6. Rotate the disk (key 3) to the fully open position.
7. Locate the small ends of the taper pins. Drive the two taper pins (key 10) out towards the larger end of the pins.
(Note: Attempting to drive the taper pins in the opposite direction only tightens the pins.) Also, remove the hollow
pins (key 9) from the disk/shaft connection using the tool shown in figure 11.
Note
Make the tools for removal and installation of the hollow pin shown in figure 11.
8. Unscrew and remove the packing flange nuts (key 101), and the packing flange (key 102).
WARNING
Once the shaft has been removed in the following step, the disk may fall out of the valve body cavity. To avoid personal
injury and property damage, support the disk to prevent it from falling as the shaft is being removed.
9. Pull the shaft out of the valve body, and remove the disk (key 3) from the valve body bore.
10. If the packing is to be replaced, remove all the packing parts from the valve body. Upon re‐assembly of the valve,
refer to the Packing Maintenance procedures to replace the packing parts.
11. Remove both of the bearings (key 6) from the valve body.
12. Clean all the sealing surfaces and parts, and inspect and/or obtain replacements before assembly.
Assembly
1. Install the bearings (key 6):