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Masoneilan Regulators Models 525 & 526 Manual | 6
I.
Select the correct size pin, apply a small amount of
grease on it and press into the hole.
Note: The pin must be recessed approximately 1/16" below
the plug guide surface.
J.
After the plug has been pinned it should be placed in
a lathe to ensure it is running true. If it is not, strike
the plug with a soft faced mallet to straighten.
Note: The plug should be placed in a collet with the plug
guide against it and the plug should be struck.
8.5
Packing Box
Packing box maintenance is one of the principle action
items of routine servicing. Tightness of the packing is
maintained by packing compression. Compression is
achieved by evenly tightening the packing flange nuts (15)
against the packing flange (13). Care must be taken not to
over tighten as this could prevent smooth operation of the
valve. If all compression is used up and the valve leaks,
then new packing is required.
Valve must be isolated and the pressure vented before
performing packing box maintenance.
Proceed as follows:
8.5.1
Carbon/PTFE Rings (Standard)
NOTE: The Carbon/PTFE packing rings have a skive cut
allowing packing replacement without disconnecting the
plug stem from the actuator connector or actuator stem.
A.
Loosen and remove packing flange nuts (15).
B.
Lift the packing flange (13) and packing follower
(12) up the valve stem.
NOTE: These parts may be secured using tape or wire to
keep them out of the way before proceeding.
C.
By means of a hooked instrument, remove
packing (16) insuring 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 (17) must also be removed to
gain access to lower packing rings.
D.
Replace packing rings (16).
NOTE: Assemble and compress rings one at a time into
packing box. The skive cut of each packing ring must be
placed about 120 degrees apart.
NOTE: On valves equipped with an optional lubricator
connection, refer to Figure 2 for correct amount of rings to
place under the lantern ring (17).
E.
Replace packing follower (12) and packing flange
(13).
F.
Replace and tighten packing stud nuts (15).
Do not over tighten.
G.
Place valve back in service and only tighten
packing as necessary to stop external leakage.
NOTE: In an emergency, string packing may be used as a
temporary repair only. It must be replaced with the
correct packing as soon as possible.
9.
Valve Body Reassembly
After completion of the required maintenance, the valve
should be reassembled using the following procedures:
NOTE: If any of the following steps were completed during
maintenance, then proceed to the next step.
9.1
525 (Reducing Service)
A.
CIean all gasket mating surfaces.
B.
Apply a small amount of sealant to the seat ring
threads and sealing shoulders. Install seat rings
into valve body.
NOTE: A sealant compatible with the process should be
applied sparingly.
C.
lnstall and tighten seat rings using wrench used
for removal.
Do not over-tighten. Do not strike seat ring lugs directly.
This could distort the seat ring resulting in unwarranted
seat leakage.
D.
Install body-blind head gasket
E.
Install blind head
Tighten nuts (10) until metal to metal contact is obtained
with proper bolt torque. Refer to Table 1 for proper bolt
torque and tightening sequence specifications.
F.
Carefully install plug and stem assembly,
carefully inserting lower guide into lower
bushing.
NOTE: Valve should be lapped before final assembly. See
Section 8.3.
G.
Install body gasket (22).
NOTE: Spiral wound body gaskets (22) are standard in the
500 Series design. It is imperative that a new gasket be
installed each time the valve is disassembled.
Summary of Contents for Masoneilan 525
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