Cashco SCV-30 - Manual (Page 6)

IOM-SCV-30 6
B. Procedure – Reverse Ac tion, ATO-FC:
1. Reference the name plate (40) at tached to
the actuator yoke (3). De ter mine the bench
set ting of the installed range springs (10) from
the name plate (40).
2. Connect a temporary air supply with an in-line
ad just able airset reg u la tor and gauge to the
lower actuator con nec tion. DO NOT LOAD
with any air pressure at this point.
3. To determine when stem/plug (3) begins to
lift out of the seat, touch the stem below the
coupling with one fi nger. (Stem will begin to
move when actuator pressure exceeds the
spring load.)
4. Slowly pressurize the ac tu a tor to a pres sure
equal to the lower pres sure level of the bench
setting; i.e. for 5-15 psig (.34–1.03 Barg) range,
set pressure at 5 psig (.34 Barg). Take note
of pressure reading when the stem fi rst begins
to move.
5. If the loading pressure for the start of stem
movement is below the lower end of the
desired bench setting, then the com bined
stem (3, 6) length is too short.
a. Rotate jam nuts (17) down to base of
threads on upper collar (42a).
b. Increase pressure in actuator to approxi-
mately mid range of the bench setting.
c. Rotate upper collar (42a) CCW to increase
the combined stem length. DO NOT allow
actuator stem (6) to rotate in the actuator.
d. Rotate upper jam nut CW to hold indicator
washer (16) up against stem (6).
e. Release all pressure from the actuator
and repeat Step 4 previous.
6. If the loading pressure for the start of stem
movement is above the lower end of the
desired bench setting, then the com bined
stem (3, 6) length is too long.
a. Rotate jam nuts (17) down to base of
threads on upper collar (42a).
b. Increase pressure in actuator to approxi-
mately mid range of the bench setting.
c. Rotate upper collar (42a) CW to shorten
the combined stem length. DO NOT allow
actuator stem (6) to rotate in the actuator.
d. Rotate upper jam nut CW to hold indicator
washer (16) up against stem (6).
e. Release all pressure from the actuator
and repeat Step 4 previous.
7. After the opening set point pressure has been
established, rotate lower jam nut (17) CW up
tight under the upper jam nut.
8. Release all pressure from the actuator.
9. Observe the location of the in di ca ting washer
(16) to the "C" mark on the in di ca tor plate
(23), mak ing sure to use the “top edge” of the
in di ca ting washer (16) as the ref er ence point.
Adjust indicator plate as needed.
10. Slowly increase the pressure in the actuator
until the indicating washer (16) is in alignment
with the "O" mark on the indicator plate.
11. To limit the up travel at the desired stroke
length, rotate the travel stop nut (52) CW and
secure to bottom of attachment hub (4).
NOTE: Secure the actuator stem (6) by the
fl ats when rotating the travel stop nut.
NOTE: "Stroke" length is indicated on the
nameplate (40), and is the distance between
the "C" and "O" marks of the indicator plate
(23).
NOTE: The proper calibration of the actuator
/ valve unit will occur when at the lower pres-
sure level of bench setting, the valve plug (3)
will just begin to travel from the "C" position.
At the upper level of the bench setting, the
actuator pressure should be within ±8% of
the upper bench range for the desired stroke
length.
12. Release all pressure from actuator.
C. Procedure – Direct Action, ATC-FO:
1. Reference the nameplate (40) attached to
the actuator yoke (3). Determine the bench
set ting of the installed range springs (10) from
the nameplate (40).
2. Connect a temporary air supply with an in-line
ad just able airset regulator and gauge to the
upper actuator con nec tion. DO NOT LOAD
with any air pressure at this point.
3. To determine when stem/plug (3) makes
contact with the seat and travel stops, touch
the stem below the coupling with one fi nger.
(Stem movement will stop when the plug
engages the seat.)
4. Slowly pressurize the ac tu a tor to a pres sure
equal to the upper pres sure lev el of the bench