Instruction manual

Instruction Manual
D500248X012
A31D Valve
April 2014
20
CAUTION
To avoid damage to the taper key, tangential 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 that the taper key spans t he 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 MAXIMUM 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 7. For NPS
3, 4, and 6 valves, use an arc spot weld bead of 1/8-inch diameter. For NPS 8, 10,and12valves,useanarcspotweld
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).
Figure 7. Fisher A31D Taper Key Weld Location
A5947
WELD LOCATION
WELD
LOCATION
TAPER KEY
SHAFT
DISK
MINIMUM TAPER KEY ENGAGEMENT
MAXIMUM TAPERKEYENGAGEMENT
VIEW A
TAPER KEY WELD LOCATION
Installing the Two-Piece Shaft
Note
In these instructions, the drive shaft (with splined or keyed end) is key 3. The shaft opposite the drive shaft is called the follower
shaft (key 4).