Actuator Maintenance
It is necessary for efficient and
proper operation of the actuator that
all parts be free from dirt, abrasives.
and foreign materials. Upon assembly
at the factory. all synthetic rubber
O-rings have been coated with LUB-
RIPLATE 130.AA, a special lubricant
manufactured and distributed by Fiske
Brothers Refining Company of
Newark. New Jersey, and Toledo.
Ohio. It is recommended that his lubri-
cant ,be used on all O-rings, especially
those on moving parts or in contact
with moving parts. whenever the ac-
tuator is dismantled.
To disassemble a Fisher piston ac-
tuator, proceed as follows:
(References to “positioner” can be
ignored if either a 481 or a 489 ac-
tuator is involved.1
1. Bypass the valve body or shut
off the pressure in the pipeline.
Caution: The adjustable linkage be-
tween the actuator and the main valve
should not be disconnected when the
valve is open with fluid flowing.
(Dampers or louvers should be in safe.
stable positions prior to discon-
nection.)
2. Shut off all pressure to the ac-
tuator. Remove all tubing lines
Icylinder. instrument, and supply)
from the actuator.
3. Remove positioner cover after
loosening the four cover screws on the
underside of the positioner base.
4. Disengage range spring by un~
screwing the spring retainer from the
piston rod extension.
5. Loosen the two cap screwy that
hold the positioner to the cylinder.
When removing the positioner. do not
lose the small O-ring that is used in the
passage from the positioner to the top
of the cylinder.
6. Next remove the clevis bolt
from the adjustable linkage. Remove
the bottom snap ring (Key 26) and un-
screw the cleuis and the boot locknut
from the actuator piston rod.
7. Remove the nuts that hold the
cylinder to the mounting flange and
lift off the cylinder.
8. Remove the stud bolts (Key 13)
that hold the cylinder to the cylinder
flange. Two slots. 180” afx,rt. are lo
Types 480,481, & 489
cated at the lower edge of the
cylinder. Insert a screwdriver in these
slots and pry the cylinder loose. The
pet011 and piston rod will come out
with the cylinder. The piston can then
be removed by pulling it out the open
end of the cylinder,
9. Unscrew both seal bushings,
(Keys 7 and 8).
10. Inspect all parts for eXcessi”e
wear and defects. Replace all worn
O-rings. Lubricate as mentioned above.
11, To reassemble, reverse the
above procedure.
Serial Numbers
Always include the serial number of
your actuator when consulting your
representative for technical advice or
ordering replacement parts. Also in-
clude the complete part number listed
in, the following parts reference sec.
fion. (Some valve types. notably
butterfly valves. do not have the same
valve serial number as the actuator.
Therefore. for proper cross reference,
always include the valve serial number
if it differs from the actuator serial
number.)
Parts Reference Types 480, 481, and 489
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