Cashco 964 - Manual (Page 5)

IOM-964 5
to help stabilize top works, continue to pres-
sur ize the ac tu a tor in 2-3 psi (.15-.20 Bar)
in cre ments in an al ter nat ing se quence with
the distance en gaged until the total num ber
of revs engaged is reached.
8. Hand-tighten yoke nut (17) until fully po si tioned
with the yoke (1) sitting on the bonnet (2).
9. Secure “dangling parts” - ac ces so ry plate
((AP)) and indicator disc (20) - to ac tu a tor
stem (19) with stem jam nuts (18).
10. Properly position the actuator yoke (1) with re-
spect to the body (1), and ham mer rap yoke nut
(17) until tight. (Release tem po rary air source.)
11. Calibrate actuator-to-valve per Sec tion V.
D. Trim Removal and Re place ment:
1. Secure body (1) assembly (BA) in a vise with
actuator assembly (AA) di rect ed up wards.
Place match marks be tween the body (1) and
the bonnet (2).
2. Secure the actuator assembly (AA) with an
over head support capable of ver ti cal ly hoist ing.
3. (Note PA.) Loosen all bonnet stud nuts (17).
4. Ensure actuator support is “taut”; i.e. hold ing
weight of actuator.
5. Remove all bonnet bolting nuts (17).
6. Lift the actuator assembly (AA), to geth er with
bon net (2) and stem as sem bly (3) vertically
out of the valve body (1). NOTE: For ATO-
FC
action units, the re mov al will also pull the
seat ring (11) out si mul ta neous ly. Lay the
topworks assembly down onto a work bench
horizontally. For ATC-FO action units, re move
the seat ring (11) from the body (1) cavity.
7. Turn attention to the removed top works as sem-
bly. Loosen the stem jam nuts (18) by rotating
CCW (viewed from plug end) while se cur ing
the actuator stem (19) with soft-jawed pliers.
8. Loosen stem packing (6) by turn ing nuts (15)
CCW to a point just short of dis en gage ment
of threads.
9. While securing the actuator stem (19) by soft-
jawed pliers, rotate the valve stem as sem bly
(3) CCW (viewed from plug end). Record the
number of rev o lu tions of dis en gage ment in
the box below:
CAUTION
Take extreme care to not mar internal wall surface
of the bonnet (2).
Number of revolutions to disengage valve stem
assembly from actuator stem.
10. Remove packing fl ange nuts (15) with CCW
ro ta tion.
11. Partially withdraw stem/plug as sem bly (3).
Re move position in di ca tor disc (20), both
jam nuts (18), packing fl ange (4), pack ing
follower (5), and ac ces so ry plate ((AP)), if
installed.
12. Fully withdraw stem/plug as sem bly (3).
13. Using a sharp, hooked-end, pick-type tool,
hook and pull the packing rings (6) up and out
of the bonnet’s (2) stuffi ng box individually.
Examine for proper orientation (see Figure
4). Discard old packing (6).
14. Using a sharp pointed tool, remove packing
washer (23) and packing spring (24).
15. Solvent clean all loose parts with suitable
solvent and let dry.
16. Inspect guide bush ing (8) in-place, as the
bush ing (8) is a press fi t into the bonnet (2).
If worn or “scored:
a. Remove bonnet (2) by re mov ing yoke
nut (17).
b. Remove snap-ring (9).
c. Hydraulically press guide bush ing (8)
“out”; press “in” new guide bushing (8)
into bon net (2).
d. Replace snap-ring (9).
e. Reinstall bonnet (2) back to geth er with ac-
tu a tor yoke (1), securing with yoke nut (17).
17. Examine seat ring (11), com po si tion seat
(3.4), stem (3.1) or plug (3) or adapt ers (3.3)
(3.5) for wear. Re place all worn parts.Refer
to Figure 3 for correct composition seat ar-
rangement.