Instruction manual

Instruction Manual
D500240X012
A31A Valve
October 2012
21
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 portion of the journal
bearing will extend into the valve body bore.
4. Insertonejournalbearingfromthevalvebodyboreintotheshaftbearingboreoppositethejournalbearing
installed in step 3. When correctly installed, this journal bearing will be flush with the valve body bore.
5. Installthevalvediskbyplacingthediskintothevalvebodyboresothecurvedsideofthediskpassesthroughthe
end of the valve body that does not contain the T-slot. Align the shaft bore in the disk with the bearing bores.
6. Insertthedriveshaftendoppositethekeyedendintothevalvebodythroughthepackingbox.Pushtheshaft
through the bearing stop. Taking care not to dislodge 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, tangential 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 material from
the taper key.
8. Alignthetaperkeyholeintheshaftwiththeholesintheshaftbossonthedisk.Insertthetaperkey.Useaflat-end
punch to drive the taper key until solid contact 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, NPS MINIMUM DEPTH TO DRIVE TAPER KEY AFTER INITIAL SOLID CONTACT
CL150 and 300, NPS 3, 4, 6 valves, & NPS 8 CL150 valves 5 mm (0.188 INCHES)
b. The disk shaft, and taper key assembly must be inspected to verify t hat the taper key spans the entire shaft flat
width. If so, this procedure is complete. If not, the taper key must be driven in farther until this condition is
satisfied. However, do not exceed the following depth limits:
VALVE SIZE, NPS MINIMUM ALLOWABLE DEPTH TO DRIVE TAPER KEY AFTER INITIAL SOLID CONTACT
NPS 3 and 4 CL150/300 7 mm (0.281 INCHES)
NPS 6 CL300, and NPS 8 CL150 8 mm (0.312 INCHES)
9. After driving the taper key in place, arc spot weld the head of the taper key to the disk as shown in figure 8. For NPS
3, 4, and 6 valves, use an arc spot weld bead of 1/8-inch diameter. For NPS 8, 10, and 12 valves, 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 Rotary Packing
Instruction Manual (D101643X012).
Installing a Two-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 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.
CAUTION
Premature valve failure and loss of process control may result if bearings are improperly installed or are damaged during
installation.