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7.6.2 Flexible Graphite Rings (Optional – See Figure 6)
Note: Flexible graphite packing rings replacement may require
disconnecting the plug stem from the actuator stem and
removal of the actuator if rings are not skive cut.
A. Remove actuator from the body S/A. Refer to actuator
instruction Ref. 19530 for a type 87/88 actuator.
B. Loosen and remove packing flange nuts (3).
C. Remove packing flange (4) and packing follower (5) from
the plug stem.
D. By means of a hooked instrument, remove packing (6)
ensuring not to damage the sealing surfaces of the packing
box or plug stem.
Note: On valves equipped with an optional lubricator
connection, the lantern ring (7) must also be removed to
gain access to lower packing rings.
E.
Replace new packing set (6); first assemble a back-up ring
(Graphite Filament Yarn braided ring), then the flexible
graphite rings (smooth rings), and finally another braided
back-up ring (refer to Figure 6).
Note: Assemble and compress rings one at a time into
packing box.
WARNING
Note: On valves equipped with an optional lubricator
connection, refer to Figure 10 for correct arrangement
according to valve size.
F.
Assemble packing follower (5) and packing flange (4).
G. Assemble and tighten packing stud nuts (3).
CAUTION
Do not overtighten.
H. Proceed to appropriate instructions for actuator and valve
CAUTION
assembly adjustment.
I.
Place valve back in service and only tighten packing as
necessary to stop external leakage.
7.6.3 LE Packing (Optional – See Figure 7)
The Masoneilan LE (Low Emissions) Packing from Baker
Hughes is a high performance packing system capable of
containing fugitive emissions well below the specifications of the
most severe recommendations. It is also available in a firesafe
configuration.
The packing is provided as a set of five pieces. It consists of
two adapter rings and three V-rings. An alternating pattern of
Perfluoroelastomer (PFE) and long carbon fiber filled Teflon
(PTFE) V-rings are used.
Applied properly, this packing exhibits very little cold flow (or creep).
Consequently, it can effectively prevent fugitive emissions leaks
from a control valve. The LE Packing system can directly replace
conventional packing, requiring no modification to the control
valve or actuator.
A spring loaded, two-piece follower assembly is used to maintain
a constant load on the packing, and is necessary for thermal
cycling applications. As the definition of thermal cycling can vary,
and processes are potentially subject to unpredicted thermal
gradients, LE Packing is only available with the spring loaded
follower.
Installation should be performed as detailed in the following
paragraphs.
Copyright 2023 Baker Hughes Company. All rights reserved.
DANGER
7.6.3.1 Preparation
7.6.3.1.1 Stem
Inspect stem for any nicks or scratches on the surface
finish. Reject the stem for any of these reasons as they may
damage packing.
Note: A properly etched part number on the stem in
the packing area will have no adverse effect on the
performance of the packing.
WARNING
Stem finish should be 3-7 AARH (Ra 0,1/0,2).
7.6.3.1.2 Packing Box
Note: Bonnets that have a lube hole or leak detection
port are unacceptable for use with the packing
arrangement shown in Figure 7.
CAUTION
Packing box should be clean and free of burrs, rust,
and any foreign matter. Parts can be cleaned with
denatured alcohol.
CAUTION
Note: Packing box finish should be 125 AARH (Ra 3,2)
or better.
The packing box may be bored or honed oversize by up to
0.015" (0.38 mm) above the nominal diameter to improve the
finish. For instance, a nominal 0.875" (22.22 mm) packing box
may be bored or honed up to 0.890" (22.60 mm) and the LE
Packing will still seal properly.
Packing box must be finished to the bottom of the bore.
7.6.3.1.3 Packing
Inspect packing rings. Do not use packing if any nicks or
scratches on packing are observed. Check packing and
ensure that it is in the proper arrangement (see Figure
below). PFE material can be identified by the gloss black
molded finish. PTFE material has a dull black machined
finish.
PFE - V -Ring
PFE - V -Ring
7.6.3.1.4 Spring Loaded Follower
The spring loaded follower consists of an upper and lower
follower and eight (8) disc springs (see Figure below). The
springs are installed inside the lower follower and positioned
alternately. The assembly is held together by tape, which
must be removed before installation.
Scribe
Mark
Masoneilan 21000 Series Top Guided Globe Valve Instruction Manual | 7
DANGER
PTFE - female adapter
PTFE - V -Ring
PTFE - male adapter
Upper
Follower
Disc
Springs
Lower
Follower
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