Trim Maintenance; Replacing Valve Plug, Seat Ring(S) And Guide Bushings - Emerson Fisher HS Instruction Manual

Control valve - obs valve
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Instruction Manual
D100381X012
Table 5. Recommended Torque for Packing Flange Nuts (Non Live‐loaded Graphite Packing)
STEM
DIAMETER
mm
Inches
12.7
1/2
12.7
1/2
19.1
3/4
19.1
3/4
25.4
25.4
31.8
1‐1/4
31.8
1‐1/4
50.8
1. For intermediate class ratings, use the same torque as the next lower standard class.

Trim Maintenance

WARNING
D Observe the warnings at the start of the Maintenance section.
Replacing Valve Plug, Seat Ring(s), and Guide Bushings
1. Isolate the control valve from the line pressure, release pressure from both sides of the valve body, and drain the
process media from both sides of the valve. If using a power actuator, also shut-off all pressure lines to the power
actuator, release all pressure from the actuator. Use lock-out procedures to be sure that the above measures stay in
effect while you work on the equipment.
2. Disconnect the valve stem from the actuator by unscrewing the cap screws and removing the stem connector.
3. To remove the valve plug, use the appropriate procedure below:
For direct-acting valves:
a. Disconnect all pressure lines from the actuator. Unscrew the yoke locknut (valves with 3/8, 1/2, or 3/4-inch
stems) or eight cap screws and nuts (valves with 1 or 1-1/4 inch stems). Remove the actuator from the valve.
b. Unscrew the bonnet bolts bonnet nuts (steel valves). Remove the bonnet, valve plug , and stem as a unit.
c. Loosen the packing flange nuts and carefully slide the valve plug and stem out of the bonnet.
4. To replace the guide bushings, press them out of the bonnet and bottom flange. If the bushings cannot be removed
in this manner, machine out the old bushings. Press the new bushings into place. Spin or crimp the bushing
retaining lip into place per figure 7.
VALVE BODY
(1)
RATING
CL900
CL1500
CL900
CL1500
1
CL900
1
CL1500
CL900
CL1500
CL1500
2
TORQUE
NSm
Min
Max
12
18
15
22
27
41
34
50
42
62
52
77
56
83
68
102
98
146
HS Valve
June 2019
lbfSft
Min
Max
9
13
11
16
20
30
25
37
31
46
38
57
41
61
50
75
72
108
9

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