Masoneilan VariPak Adjustable Cv Control Valves Instruction Manual
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Follow the procedure described in the "Disassembly/
Reassembly" section of the "Maintenance" chapter on
pages 14 to 18.
- Also change the serial plate (135) or correct the
information on the existing plate.
Caution: If the valve in question includes
a 1/2" or 3/4" NPT threaded end, the
maximum capacity of the body is
respectively limited to trim Nos. 9 to 3
inclusive or 9 to 2 inclusive. A trim No. 9
cannot be installed in a VariPak valve body
designed for a trim No. 0. Likewise, a trim
No. 0 cannot be installed in valve bodies
designed for other trim numbers.
2.2.3 Adjusting the Cv of a Varipak 28002 valve for
each plug and seat ring combination
This is done by moving adjustment knob (24) along
adjustment plate (25) fastened to the top of lever No.
1 (21).
The adjustment plate (25) gives the range of Cv
values offered by the selected plug and seat ring
combination. Carry out this adjustment operation as
follows:
Figure 4 - Adjusting the
Cv
of VariPak 28002 valve for each
plug/seat ring combination
- Loosen adjustment knob (24) and slide it along the
lever to the required value. Tighten the adjustment
knob again firmly.
Note:
- This operation entails moving lever No. 2, either
pneumatically (by allowing air into the actuator),
or manually (by pressing piston clevis (140b) with a
screwdriver or similar tool) so that the slides of the
two levers are perfectly parallel.
- It may be necessary to reset the zero to calibrate the
closure point after changing the Cv.
2.3 ACTUATOR
A single actuator allows VariPak valves to act in
direct Air-to-Close (ATC), or reverse Air-to-Open (ATO).
Valve action can be changed with no additional part
by simply shifting:
- the pivot pin and the attachment hole of the
positioner balance spring clamp for the singlelever
VariPak 28001 valve,
- the two pivot pins for the adjustable-Cv VariPak
28002 valve, then calibrating as required.
Follow the instructions given under "Reversing the
valve action" on page 8.
2.4 HANDWHEEL(Figure 5)
The handwheel is an optional feature located on top
of the cover and fitted with a locking lever. Access
can be gained to it directly without removing any
other parts. It consists of a threaded rod, equipped
with a handwheel (120) and a lever arm stop (122).
The threaded rod rests freely on the actuator bracket
(108) and is guided through the cover (110) by
handwheel bushing (119). The stop consists of a block
screwed onto the threaded rod. The block is guided
by the actuator bracket (108).
Figure 5
