Cashco 2296HF - Manual (Page 5)

5 IOM-2296
5. For ATO-FC Reverse Action Units:
a. (Note PA.)
b. Step A. Rotate valve stem (4) CW (viewed
from above) to disengage the ac tu a tor stem
(6) from the plug/stem (4), while holding
the actuator stem (6). Count and record
the num ber of valve stem rev o lu tions for
Step A above. When the dis en gage ment
reach es about 50% of full stroke trav el,
(Note RP.). Step A is com plet ed.
c. Step B. Support the actuator as sem-
bly (AA) from above. Fully loosen
yoke nut (15). Lift the actuator as-
sem bly (AA) up wards ap prox i mate ly
1/4"-3/8" (6-8 mm). Again, rotate valve stem
(4) CW (viewed from above) to dis en gage
the ac tu a tor stem (6) from the plug/stem
(4) while holding the ac tu a tor stem (6).
Count and record the number of valve stem
rev o lu tions for Step B above. This should
allow the stems (6) (4) to fully dis en gage.
NOTE: Take notice of the parts “dan gling
loosely” about the stem (4), the order of their
lo ca tion, and their proper orientation.
d. Fully raise the actuator assembly (AA) from
the valve body assembly (BA). Re move
cautiously to prevent dan gling parts - ,
position indicating washer (16), ac ces so ry
plate ((AP)), yoke nut (15) - from fall ing.
6. For ATC-FO Direct Action Units:
a. Step A. Rotate valve stem (4) CW (viewed
from above) to disengage the ac tu a tor stem
(6). DO NOT rotate the plug/stem (4) down
into the seating surface. Count and record
the number of plug/stem (4) rev o lu tions for
Step A above. When the dis en gage ment
reach es about 75% of full stroke travel,
Step A. is com plet ed.
b. Step B. Support the actuator as sem bly
(AA) from above. Fully loosen yoke
nut (15). Lift the actuator as sem bly
(AA) upwards ap prox i mate ly 1/4" -
3/8" (6-8 mm). Again, rotate plug/stem
(4) CW (viewed from above) to dis en gage
the ac tu a tor stem (6) from the plug/stem
(4), while holding the actuator stem (6).
Count and record the number of plug/stem
rev o lu tions for Step B. This should allow
the stems (6) (4) to fully disengage.
NOTE: Take notice of the parts “dangling
loosely” about the stem (4), the order of their
lo ca tion, and their proper orientation.
c. Fully raise the actuator assembly (AA) from
the valve body assembly (BA). Re move
cau tious ly to prevent dan gling parts - po si-
tion indicating washer (16), ac ces so ry plate
((AP)), yoke nut (15) - from falling.
C. Actuator Replacement:
1. Secure body assembly (BA) in a vice with the
plug/stem (4) oriented ver ti cal ly. Push plug/
stem (4) down until the plug touches the seat-
ing surface in the body (1).
2. Secure the actuator assembly (AA) from above.
Use matchmarks from B.1. previous to assist
with (BA) and (AA) alignment.
3. This procedure assumes that the bonnet (2)
has been installed to the body (1), with stem
jam nuts (17) on the plug/stem (4)
. (Note PA.)
4. Lower actuator assembly (AA) until the plug/
stem (4) penetrates the opening in the yoke
(3). Re po si tion the “dangling parts” - yoke nut
(15), ac ces so ry plate ((AP)) and in di cat ing
washer (16) - over the plug/stem (4). Con tin ue
to lower the actuator assembly (AA) until there
is ap prox i mate ly 1/4" (6 mm) space between
the two stems (6) (4).
5. For ATC-FO: Connect a temporary air supply
hose that has an ad just able airset with gauge
to the ac tu a tor inlet to allow pres sur iza tion.
Slowly pressurize actuator to bring the ac tu a tor
stem (6) to be with in 1/8" (3 mm) of contacting
the plug/stem (4).
6. With hand, lift stem (4) up to touch ac tu a tor stem
(6). Rotate plug/stem (4) CCW (viewed from
above) to en gage w/ ac tu a tor stem (6). Use the
total number of revs en gage ment recorded in
Step V.B.4. as the guide to control engagement
of the stems (6) (4). While en gag ing the stems,
rotate yoke nut (15) as able 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.
7. Hand-tighten yoke nut (15) until fully po si tioned
with the yoke (3) sitting on the bonnet (2).