Instruction manual

Instruction Manual
D500248X012
A31D Valve
April 2014
17
Anti-Blowout Protection, Packing, Valve Shaft(s), Disk, and Bearing
Maintenance
Removal
Note
NPS 3 through 8 valves (CL150) and NPS 3 through 6 valves (CL300) have a bearing stop pressed into the bearing bore
immediately after the packing box.
Do not attempt to remove the bearing stop which is found in the drive shaft bearing bore immediately after the packing box. The
bearing stop is pressed into the bearing bore. If the bearing stop needs replacement, contact your Emerson Process Management
sales office for more information.
Note
The A31D valve has a two-piece shaft. In these procedures, the drive shaft is key 3. The shaft opposite the drive shaft is called the
follower shaft (key 4).
CAUTION
When using an actuator, the actuator travel stop (or actuator travel adjustment, for actuators without adjustable stops)
must be adjusted so the disk stop in the valve does not absorb the output of the actuator. Failure to limit the actuator travel
as described in the next step can result in damage to the valve, shaft(s), or other valve components.
CAUTION
When removing the actuator from the valve, do not use a hammer or similar tool to drive the lever off the valve shaft.
Driving the lever or actuator off the valve shaft could damage the valve internal parts.
If necessary, use a wheel puller to remove the lever or actuator from the valve shaft. It is okay to tap the wheel puller screw
lightly to loosen the lever or actuator, but hitting the screw with excessive force could also damage internal valve parts.
Key numbers in this procedure are shown in figure 9, 10, or 11 unless otherwise indicated.
1. Remove the valve from the pipeline. Remove the actuator from the valve.
WARNING
Avoid personal injury or property damage caused by the impact of a falling or tipping of a large valve. Support large valves
during maintenance.
CAUTION
Never use a wrench, pliers, or similar tool to turn the drive shaft. A damaged shaft can cut the packing and allow leakage.