Table 3: Recommended Torque for Packing Flange Nuts
Stem Diameter
Valve Class
Rating
Lbf•Ft
N•M
Inch
mm
Min
Max
Min
Max
1/2
12.7
1500
11
16
15
22
2500
13
18
18
24
3/4
19.1
1500
25
37
34
50
2500
30
45
41
61
1
25.4
1500
38
57
52
77
2500
45
67
61
91
1-1/4
31.8
1500
50
75
68
102
2500
60
90
81
122
ADDING PACKING RINGS
When using packing with lantern ring it may be
possible to add packing rings above the lantern
ring as a temporary measure without removing
the actuator from the valve body.
1.
Isolate the control valve from the line
pressure and release the pressure from the
valve body.
2.
Remove the packing flange nuts (key 18,
Figure 7) and lift the packing flange (key 16),
upper wiper (key 20) and packing follower
(key 21, Figure 7) away from the valve body.
3.
Take care when removing out the old packing
rings to avoid scratching the valve plug stem
or packing wall. Clean all metal parts to
remove debris that would prevent the packing
from sealing properly.
4.
Should split ring packing be added, spread the
rings over the stem and slide the rings into
the packing box. Alternate the position of the
splits to avoid creating a leak path. If solid ring
packing is being added, remove the stem
connector and slip the rings over the end of
the valve stem.
5.
Re-assemble the packing follower, upper
wiper, packing flange, and packing flange
nuts. (keys 21, 20, 16, and 18).
6.
Reconnect the body actuator stem connection
according to the appropriate manual. Torque
accordingly, reference Table 3.
REPLACING PACKING
Prior to beginning any maintenance, it is
important to isolate the valve from the line
pressure, and to release all pressure from the
valve body. Disconnect all operating lines to the
actuator, including air pressure, electrical power
or control signal lines. The process pressure
should be released both upstream and
downstream of the valve. Drain the process fluid
from both sides of the valve.
Employ lockout procedures to ensure the safety of
personnel and equipment during the valve
service.
NOTE: Extreme caution must be used during the
disassembly. Nicks and scratches will affect the
ability to seal the valve in the future.
1.
Remove the capscrews in the stem connector
and separate the two halves. Exhaust all
actuator pressure if any was applied, and
disconnect the actuator supply and leak off
piping.
2.
Remove the yoke locknut, and remove the
actuator from the bonnet (key 2).
3.
Loosen the packing flange nuts (key 18), and
remove any travel indicator parts and stem
locknuts from the valve stem threads