Masoneilan 77000 Series Control Valves Instruction Manual | 9
Copyright 2021 Baker Hughes Company. All rights reserved.
Preparation
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.
Stem finish should be 3-7 AARH (Ra 0,1/0,2).
Packing Box
Note: Bonnets that have a lube hole require installation of
a lantern ring within the packing arrangement shown in
Figure 8.
Packing box should be clean and free of burrs, rust,
and any foreign matter. Parts can be cleaned with
denatured alcohol.
Note: Packing box finish should be 125 AARH (Ra 0.8) 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 Low-E Packing
will still seal properly.
Packing box must be finished to the bottom of the bore.
View shown with graphite packing option
and lantern ring with lube hole
22
16
17
hown with graphite packi
22
16
17
Figure 8 - Packing Box
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 9). 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
PTFE - V-Ring
PTFE - male adapter
PTFE - female adapter
Figure 9
Spring Loaded Follower
The spring loaded follower (available for applications rated ANSI
300 and below) consists of an upper and lower follower and eight
(8) disc springs (see Figure 10). 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
Upper
Follower
Lower
Follower
Disc
Springs
Figure 10 - Spring Loaded Follower
Packing Installation
1. The packing must be lubricated with Krytox® fluorinated
grease prior to installation (Krytox GPL206 or equivalent).
2. Packing should be lubricated as a set (not individually) to
minimize getting lubricant between the rings.
3. Packing should be lubricated with a generous application to
the O.D. and I.D. of the packing set.
Note: All exposed surfaces of the packing set must be
covered with the lubricant.
4. PFE/PTFE is to be installed as a set. Carefully slide the
packing set down the stem. Do not cock or force the packing
on the threads.
If the packing set separates while on the stem, do not
remove. Continue installing the remaining pieces to put the
set back together.
5. Gently press the packing into the packing box. Do not tap
the packing down into the box.
6. The spring loaded follower is installed on top of the packing.
This follower is installed as an assembly held together by
tape. This tape should be removed after assembly. Proper
assembly of the packing box will leave the top of the Lower
Follower 0.25 - 0.50 inches (6 to 13 mm) above the bonnet.
A groove is scribed into the O.D. of the upper follower. The
packing flange is tightened evenly until the top of the Lower
Follower aligns with the scribe mark (groove) in the Upper
Follower.
Note: This is the optimum loading for this packing.
Further tightening will shorten life of the packing.
Thread locking compound can be used on packing nuts.
7. The packing should be checked for leakage.
8. Packing load should be checked after the valve has cycled
approximately 500 times. Adjust if necessary. No further
adjustment should be required for the life of the packing.
