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Vent the power actuator loading
pressure and relieve any actua-
tor spring precompression.
Use lock–out procedures to be sure
that the above measures stay in effect
while you are working on the equip-
ment.
Disassembly
1. If the actuator is installed on a control valve, isolate
or bypass the control valve.
2. Shut off the diaphragm loading pressure and re-
move the pipe or tubing from the loading pressure
connection in the top of the diaphragm case.
3. Turn the lower bearing seat (key 14) down, away
from the spring case to relieve all spring compression.
4. If the entire actuator is to be removed from its
mounting, disconnect the actuator stem (key 10) from
the stem connector, clevis, etc., and remove the jam
nuts (key 23). Loosen the cap screws that hold the
yoke (key 9) to its mounting plate or bracket, and lift
the entire actuator from its mounting.
5. Remove the diaphragm case cap screws and nuts
(keys 19 and 20) and lift the upper diaphragm case
(key 1 ) off the actuator. Remove the diaphragm (key
2).
6. Lift out the diaphragm plate (key 4) and stem (key
10). They may be separated by removing the cap
screw (key 3).
7. Take out the actuator spring (key 6).
8. The lower diaphragm case (key 5) can be removed
from the yoke, if required, by loosening the travel
stops and cap screws (keys 7 and 8).
9. Remove the lower spring seat (key 11) and thrust
bearing (key 13). Unscrew the lower bearing seat (key
14) from the adjusting screw (key 12).
10. Remove the set screw (key 22) and remove the
adjusting screw to complete disassembly.
Assembly
1. Apply Lubriplate MAG-1 lubricant, or equivalent, to
the adjusting screw threads (key 12) and screw this
into the yoke (key 9). Replace set screw (key 22). The
set screw should engage the machined thread relief in
the adjusting screw.
A
A
11A0001-A / DOC
Figure 2. Travel Stop Orientation for Size 60
2. With the eared portion up, screw the lower bearing
seat (key 14) all the way onto the adjusting screw.
3. Apply Lubriplate MAG-1 lubricant, or equivalent, to
the thrust bearing (key 13) and position it on the lower
bearing seat (key 14). Lay the lower spring seat (key
11) on top of the thrust bearing assembly.
4. Mount the lower diaphragm case (key 5) to the top
of the yoke (key 9) using the travel stops and cap
screws (keys 7 and 8). Alternate screws and travel
stops on the sizes 30 and 40. See figure 2 for the cor-
rect orientation of the size 60.
5. Position the actuator spring (key 6) on the lower
spring seat.
6. Attach the diaphragm plate (key 4) to the actuator
stem (key 10) with the cap screw (key 3). Apply Lubri-
plate MAG-1 lubricant, or equivalent, to the stem.
Place this assembly, actuator stem first, into the yoke
with the actuator stem through the spring adjustor (key
12).
7. Position the diaphragm (key 2) on the diaphragm
plate (key 4) and align the holes with the lower dia-
phragm casing (key 5). Attach the upper diaphragm
case (key 1) to the lower diaphragm casing (key 5)
using the cap screws and nuts (keys 19 and 20).
When you replace actuator diaphragms
in the field, take care to ensure the dia-
phragm casing bolts are tightened to
the proper load to prevent leakage, but
not crush the material.
Do not use lubricant on these bolts and
nuts. Fasteners must be clean and dry.
Type 656
MOUNTING BOSS
ON ACTUATOR YOKE
A
LOCATE FOUR TRAVEL
STOPS MARKED A
MOUNTING BOX
ON ACTUATOR YOKE
Note
Note
3
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