Instruction manual

Instruction Manual
D500248X012
A31D Valve
April 2014
21
Key numbers in this procedure are shown in figure 9, 10, or 11 unless otherwise indicated.
1. Properly secure the valve on a suitable worktable so it cannot slip, twist, or fall during maintenance. Be prepared to
support the valve disk. Allow for easy access to the valve body bore, drive shaft bearing bore and follower shaft
bearing bore.
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.
Note
Replacementdiskandshaftsareprovidedasamatchedsetandbothshouldbereplacedatthesametime.
2. Inspect all parts removed from the valve for wear or damage. Replace any worn or damaged parts. Clean the valve
body and all parts to be installed with an appropriate solvent or degreaser. Note: When installing the bearings,
apply lubricant to the outside diameter of the bearing for ease of installation.
CAUTION
Premature valve failure and loss of process control may r esult if bearings are improperly installed or are damaged during
installation.
3. When installing the lower bearings (key 4), insert one or more bearings i nto the follower shaft bearing bore so it is
flush with the body bore.
The number of bearings required changes with valve size and construction. Two bearings are required in the drive
shaft and two bearings in the follower shaft. If using an NPS 14 CL150 valve with metal bearings, four bearings in the
drive and four in the follower shaft will be required.
4. Hold the follower shaft thrust bearing (key 24) in the valve body bore against the counterbore of the follower shaft
bearing bore. Push the follower shaft into the bearing bore just enough to hold the thrust bearing.
5. When installing the upper bearing (key 7), insert one or more bearings into the drive shaft from the body bore into
the bearing bore below the packing box. Use caution to prevent damage to the bearing.
CAUTION
Use caution to prevent damage to the bearing when installing the upper bearing in the previous step.
6. Holdthedriveshaftthrustbearing(key24)inthevalvebodyboreagainstthecounterboreofthedriveshaft
bearingbore.Pushthedriveshaftthroughthepackingboxsideintothebearingborejustenoughtoholdthethrust
bearing.
CAUTION
To avoid damage to the disk, seal, and T-slot area, do not force the disk past the seal or T-slot area. Install the disk from the
opposite side of the valve body.