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REPAIR
Equipment Required
Valve Seat Removal Tool (available from Memphis
Service Center):
CCT3843 - for l/2-in. 0. D. copper tubing (3/8-
in nominal) valve size
CCT3833 -for 5/8- and 7/8-in. O.D. copper
tubing (l/2- and 3/4-in. nominal) valve sizes
14002734-001 Lubricant for stem, packing, and
packing nut
Lead Seal Number 2) or Crain packing of Teflon tape
for bonnet threads.
Diaphragm Replacement
Refer to Figure 3 and Table 3 while performing this
procedure.
Shut off air supply to VP522.
Disconnect air piping at actuator assembly.
Disengage slide from stem button.
Loosen the two socket head screws securing the
actuator assembly to the valve bonnet, and lift off
actuator assembly.
WARNING
The actuator is spring loaded via the large coil spring.
To avoid personal injury, carefully loosen the two
filister head screws from the spider base. Alternate a
few turns at a time while firmly holding the spider base
down against the spider.
Turn actuator upside down on a flat surface and
disassemble to remove spring load.
Turn actuator back over and remove top and
diaphragm.
Inspect diaphragm cup at this time. If the cup is badly
corroded, replace it.
Reassemble actuator assembly in reverse order with
new diaphragm.
Replace the actuator assembly on the valve bonnet and
tighten the two socket head screws.
Engage slide on the stem button.
Reconnect air piping.
Turn air supply back on.
Packing Replacement
Refer to Figure 3 and Table 3 while performing this
procedure.
through 4 of DIAPHRAGM REPLACEMENT.
the stem and disc holder assembly. A hole is provided
near the top of the stem for insertion of an awl, nail, or
similar tool to hold the stem while removing or replacing
the stem button.
Remove packing nut.
Remove packing discs (3) and packing followers from
packing nut. Retain both packing followers. Discard old
packing.
Remove packing spring from valve bonnet.
Clean out packing nut and packing spring with a
commercial solvent degreaser.
Use solvents in a well ventilated area. Avoid
prolonged inhalation of solvents or contact with the
skin. Careless handling of solvents can cause
permanent injury to the respiratory system and
skin tissue.
Inspect the spring and replace if necessary.
Inspect the valve stem for scratches or abrasions, and
replace if necessary. See STEM AND DISC HOLDER
REBUILD KIT.
Lubricate packing spring, stem, and new packing.
Assemble packing discs (cup down) and previously
removed packing followers (bevel up) in the proper
sequence.
Slide packing spring over stem into valve bonnet.
Carefully screw packing disc and spring follower
"sandwich" over stem threads.
Apply light coating of lead seal or two wraps of Teflon
tape to bonnet threads.
Install packing nut, brass tube, and stem button.
Install actuator assembly on valve body and secure.
Restore system to operation.
Stem and Disc Holder Rebuild Kit
NOTE:
When ordering a replacement stem and disc holder
rebuild kit listed in Table 4, a new brass tube, stem
button, setscrew, and three packing discs are also
included. When replacing the stem and disc holder
assembly, the other parts included should also be
replaced.
Refer to Figure 3 and Tables 3 and 4 while performing this
procedure.
Shut off air supply to the VP522.
Remove actuator assembly as outlined in Steps 1
through 4 of DIAPHRAGM REPLACEMENT. Remove
packing discs and packing followers as in Steps 2 and
3 of the PACKING REPLACEMENT section.
Remove valve bonnet for access to upper valve seat.
Inspect and replace the upper seat, if necessary, using
the required valve seat removal tool.
While the valve is open, check the integral lower seat in
the valve body for wear and clean out any foreign
matter that may be in the valve body. If the lower seat is
bad, replace the entire valve assembly.
Install the new stem and disc holder assembly and/or
upper seat.
Reassemble other parts in reverse order.
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