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GE Oil & Gas
When the handwheel (120) is turned clockwise, the
stop (122) moves up the threaded rod, compressing the
spring (134) and raising lever No. 2 (22) (VariPak 28002)
or (113) (VariPak 28001). This closes the valve if the valve
is equipped with a direct-action actuator (Air-to-Close)
and opens the valve if it is equipped with a reverse-
action actuator (Air-to- Open).
The valve can be returned to automatic mode (neutral
position), by turning the handwheel counterclockwise
until the stop (122) comes into contact with the bracket
(108).
Note: During this operation, the compression is released
when the stop (122) moves away from the lever (22)
(VariPak 28002) or (113) (VariPak 28001). Continue the
operation until a slight tension reappears, then tighten
the handwheel lock (121).
VariPak actuators are equipped with a limit stop. This
consists of parts (180) and (181), and is designed to
prevent damage to the plug and seat ring assembly
and/or the plug stem in the event of handwheel or
actuator overstroke.
Note: The limit stop is not used with air-to-open valves
fitted with a handwheel, and must be screwed down at
the bottom of the piston.
2.5 REVERSING THE VALVE ACTION
(Figures 5, 6, 26, 27 and 29)
Caution: The valve must be isolated and
pressure vented before disassembly.
A. Loosen and remove cover (110). On valves equipped
with a handwheel, loosen cover screw (109), back
off handwheel lock (121), and turn handwheel (120)
counter-clockwise to release cover (110).
B. Adjust the signal so that the valve closes. Change the
signal slightly so that the plug just moves off the seat
ring. On the VariPak 28002 adjustable-Cv valve, set
the adjustment knob (24) to the minimum Cv setting.
C. Loosen locknut (103) and, using a screwdriver,
turn the plug stem one and three-quarter turns
counter-clockwise. Shut off the signal and the supply
pressure. Slightly tighten locknut (103) against the
clevis.
D. Unlock nut (117) and completely loosen screw (116).
Unhook spring (114) from spring clamp (115).
2.5.1 VariPak 28001 single-lever valve
E. Remove retainer clips (112b) from pin (18), and remove
the pin from lever (113) and plug clevis (104a).
Note: This operation will be simplified by relieving
the load exerted on the plug clevis by the conical
compression spring (106). To do this push against the
plug stem end with a screwdriver while driving out the
pins.
F. Remove the two retainer clips (112a) from the pin (105)
and disengage it to uncouple the lever (113) from the
bracket (108).
G. Refit the levers (113) making sure that the pin (105) is
fitted into the correct holes in the lever and bracket
for the new action of the actuator (see figure 6). Fit
the spring clamp (115) into the corresponding lever
hole.
Note: Ensure that the clevis is correctly positioned before
fitting the lever on the bracket.
H. Couple the plug stem clevis (104a) to the lever (113)
following the normal reassembly procedure (step
I. in the "Reassembly" section on page 17). Then
follow the same procedure as for the VariPak 28002
adjustable-Cv valve as from step L.
2.5.2 VariPak 28002 adjustable-Cv valve (2 levers)
E. Remove retainer clips (112b) from each of the two
pins (184) and remove pins from lever (113) and plug
clevis (104a).
Note: This operation will be simplified by relieving
the load exerted on the plug clevis by the conical
compression spring (106). To do this push against the
plug stem end with a screwdriver while driving out the
pins.
F. Remove the two retainer clips (112a) from pin No. 1
(105) and disengage it to uncouple lever No. 1 from
bracket (108). Loosen adjustment knob (24) and slide
it to the maximum Cv setting. Disengage the smooth
end of the adjustment pin (23) from the groove in lever
No. 2 while removing lever No. 1.
G. Drive out pin No. 3 (18) and remove lever No. 2 (22)
from the bracket.
H. Remove the two screws (26) and refit Cv adjustment
plate (25) after turning it round to comply with the
new action.
I. Refit levers No. 1 and 2 in sequence, making sure that
pins (105) and (108) are fitted into the correct holes
in the levers and bracket for the new action of the
actuator (see figure 6).
