Type A31A
16
bore. Do not attempt to remove the bearing stop
(key 8). Remove the journal bearing from the follower
shaft bearing bore.
12. Inspect the valve body bore, bearings, bearing
bores, and packing box for damage.
Installing a One-Piece Shaft
Unless otherwise indicated, key numbers and part
names are listed in figure 8.
1. Secure the valve in an upright position. Allow for
easy access to the valve body bore. Allow for easy
access to the drive shaft bearing bore.
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.
CAUTION
Premature valve failure and loss of pro-
cess control may result if bearings are
improperly installed or are damaged
during installation.
3. Using caution to prevent damage to the bearing,
insert one journal bearing (key 7) from the valve body
bore into the drive shaft bearing bore until it hits the
bearing stop (key 8). When properly installed, a por-
tion of the journal bearing will extend into the valve
body bore.
4. Insert one journal bearing from the valve body bore
into the shaft bearing bore opposite the journal bearing
installed in step 3. When correctly installed, this jour-
nal bearing will be flush with the valve body bore.
5. Install the valve disk by placing the disk into the
valve body bore so the curved side of the disk passes
through the end of the valve body that does not con-
tain the T-slot. Align the shaft bore in the disk with the
bearing bores.
6. Insert the drive shaft end opposite the keyed end
into the valve body through the packing box. Push the
shaft through the bearing stop. Taking care not to dis-
lodge the journal bearing, push the shaft through the
journal bearing and the valve disk and into the bore on
the opposite side of the valve body.
CAUTION
To avoid damage to the taper key, tan-
gential pins, disk pins, valve disk, or
shaft(s) resulting from the application of
excessive force, use appropriate care
when driving the key or pins into the
disk hub and shaft(s). Use the right tool.
Do not use excessive force.
7. Be sure the taper key disk shaft joint is free of oil or
grease. If necessary, remove any excess welding ma-
terial from the taper key.
8. Align the taper key hole in the shaft with the holes
in the shaft boss on the disk. Insert the taper key. Use
a flat-end punch to drive the taper key until solid con-
tact is felt. Measure the depth of the taper key head
for a reference during the following steps.
a. Drive the taper key in farther as follows:
Valve Size, Inches
Minimum Depth to Drive Taper
key After Initial Solid Contact,
Inches (mm)
ANSI Class 150 and 300,
size 3, 4, 6-inch valves, &
8-inch ANSI Class 150 valves
0.188 (5 mm)
b. The disk shaft, and taper key assembly must be
inspected to verify that the taper key spans the en-
tire shaft flat width. If so, this procedure is com-
plete. If not, the taper key must be driven in farther
until this condition is satisfied. However, do not ex-
ceed the following depth limits:
Valve Size, Inches
Minimum Allowable Depth to
Drive Taper key After Initial
Solid Contact, Inches (mm)
3, and 4-inch ANSI Class 150/300
0.281 (7 mm)
6-inch ANSI Class 300, and
8-inch ANSI Class 150
0.312 (8 mm)
9. After driving the taper key in place, arc spot weld
the head of the taper key to the disk as shown in fig-
ure 8. For valve sizes 3-, 4-, and 6-inch, use an arc
spot weld bead of 1/8-inch diameter. For valve
sizes 8-, 10-, and 12-inch sizes, use an arc spot weld
bead of 3/16-inch diameter.
10. Install the packing as described in the
Packing
Replacement section or in the ENVIRO-SEAL Packing
Instruction Manual (Form 5320).
Installing a Two-Piece Shaft
Unless otherwise indicated, key numbers and part
names are listed in figure 9.
1. Secure the valve in an upright position. Allow for
easy access to the valve body bore. Allow for easy
access to the drive shaft bearing bore and the follower
shaft bearing bore.
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.
