Replacing Trim; Disassembly - Fisher 461 Instruction Manual

Instruction Manual
D100714X012

Replacing Trim

Refer to figure 6.

Disassembly

1. Remove the actuator and the bonnet according to steps 1 through 6 of the Replacing Packing section.
2. Remove the valve plug and stem assembly (keys 3 and 10) from the valve. If the stem needs to be replaced, drive
the pin (key 11) out, and unthread the stem from the plug.
CAUTION
Never use an old stem with a new valve plug. The use of an old stem requires drilling a new pin hole through the stem,
which will weaken the stem.
3. If the valve plug needs replacing, replace the entire valve plug and stem assembly. Do not reuse the old stem on a
new valve plug. If only a new stem is necessary, screw the plug onto the new stem. Drill a 4.8 mm (3/16 inch) hole
through the stem using the plug pin hole as a guide. Drive the pin into the stem and plug.
Table 3. Recommended Torque for PTFE Type Packing Flange Nuts (non live-loaded)
VALVE STEM DIAMETER
mm Inches
19.1
25.4
31.8 1-1/4
4. With the stem and valve plug assembly removed, slide the liner (key 5) out of the valve body. Inspect the seat ring
(key 2) for nicks and scratches. Make sure the valve plug and seat ring contact surfaces are free of nicks and
scratches.
5. To remove the liner (key 5), break it loose by using cap screws in the tapped holes located in the liner's flange. (In
some very hard materials, i.e., R30006, the holes have been omitted; therefore, a sleeve puller or similar device
must be used).
6. To replace the seat ring (key 2), remove the valve from the line, or remove the pipe connected to the flange. Then,
unthread the seat ring retainer (key 4), and remove the seat ring through the bottom of the valve body.
PRESSURE RATING
CL600
CL900
3/4
CL1500
CL2500
CL600
CL900
1
CL1500
CL2500
CL600
CL900
CL1500
CL2500
TORQUE
NSm
Min Max
10 15
27 41
34 50
41 61
17 25
42 62
52 77
61 91
24 36
56 83
68 102
81 122
461 Valve
June 2017
lbfSft
Min Max
7 11
20 30
25 37
30 45
13 18
31 46
38 57
45 67
18 27
41 61
50 75
60 90
11