Instruction Manual
D103302X012
A81 Valve
January 2011
13
Key numbers in this procedure are shown in figure 9 unless otherwise indicated.
1. Isolate the control valve from line pressure, and relieve pressure from the valve body. Shut off and disconnect all
lines from the power actuator.
WARNING
The edges of a rotating disk have a shearing effect that may result in personal injury. To help prevent such injury, stay clear
of the disk edges when rotating the disk (key 3).
CAUTION
Damage to the disk (key 3) may occur if the disk is not closed when the valve is being removed from the pipeline. If
necessary, apply operating pressure to the actuator temporarily to retain the disk in the closed position while removing the
valve from the pipeline.
2. Unscrew the flange bolts, and remove the valve from the pipeline.
3. Unscrew the machine screws (key 14), remove the retainer clip (key 13), and remove the seal retainer (key 2).
4. Remove the seal ring assembly (key 4).
5. The valve must be closed during seal ring installation to permit accurate centering of the seal. To install the new
seal ring assembly:
D
For a soft seal,
if the spring (key 5) was disassembled, hook the spring ends together. Work the spring into the
recess in the seal ring (key 4). Place the seal ring assembly onto the disk. Set the retainer onto the seal, making sure
proper alignment between the seal and retainer has been achieved.
D
For the metal seal ring assembly,
place the seal ring assembly onto the disk. Set the retainer onto the seal, making
sure proper alignment between the seal and retainer has been achieved.
6. Attach the seal retainer (key 2) and the retainer clips (key 13) to the valve body and secure with the machine screws
(key 14).
7. Be certain the disk is closed before installing the valve according to the Installation section on
page 4 of this manual.
Replacing the Disk, Shafts, or Bearings
Key numbers in this procedure are shown in figure 9 unless otherwise indicated.
Table 6. Follower Shaft Internal Threads
VALVE SIZE
THREAD SIZE
DN
NPS
50
2
M8 X 1.25
80
3
M10 X 1.50
100
4
M12 X 1.75
180
6
M16 X 2.00
200
8
M20 X 2.50
250
10
M20 X 2.50
300
12
M24 X 3.00
