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B. Loosen the two cap screws (141a) and remove
manifold block (144), spring (158), gasket (146) and its
three O-rings, pilot valve assembly (155 to 157), shims
(145), and O-ring (153).
Caution: Handle the shims carefully (145).
C. Loosen locknut (117) and take-up screw (116), unhook
the spring clamp from lever (22) or (113).
D. Unscrew cap screws (141b) from positioner block (147)
and remove the positioner block from the actuator
bracket.
Remove screws (148) to separate positioner diaphragm
assembly (152) and spring (154) from the positioner
block. Examine all the parts and replace if worn or
damaged.
E. Refit positioner diaphragm assembly (152) and spring
(154) to positioner block and tighten screws (148).
Check that the small signal port Oring is in its recess
in the diaphragm assembly.
F. Reinstall the block assembly on the actuator bracket.
Note: When installing the positioner block (147), turn it
so that when the manifold block (144) is installed, the
gauge(s) is(are) facing in the right direction (figure 22).
Figure 22 - Positioner assembly
Note how the positioner (147) and gasket (146) are oriented
G. Check that gasket (146), three O-rings, and seats are
not worn or damaged and replace if necessary.
H. Fit O-ring (153), shims (145), pilot valve assembly,
gasket (146) and its three O-rings, spring (158) and
manifold block (144). Tighten the screws (141a), refit
tubing (140) and tighten pressure connection nuts
(138a).
Note: The ports in gasket (146) must be aligned with
those in the positioner block (147).
To ensure correct positioner performance, check that all
gaskets are perfectly leaktight.
I. Hook spring clamp (115) to lever (22) or (113). In the
case of VariPack 28001 valve, see figure 6 to position
the spring clamp (115) according to the actuator
required action. Admit the supply pressure and
the signal. Set the start-up pressure following the
instructions given in the "Calibration" chapter. Put
back into service.
Positioner
Signal (Psi)
3-15
or
6-30
or
3-27
7700P
3-9
9-15
7700E
4-20 mA
Figure 23 - Color code for positioner springs
(114 and 154)
5.7 MAINTENANCE OPERATIONS SPECIFIC TO THE
7700E POSITIONER
REFER TO ATEX INSTRUCTION MANUAL
No. 185977 FOR ALL MAINTENANCE ON
THE ELECTRICAL PARTS OF THE 7700E
POSITIONER.
A. Loosen screws (27) and remove I/P module (20).
Note: If damaged, the I/P module must be replaced.
B. Check that O-rings (28, 29 and 30) and their seats are
not worn or damaged.
Note: All worn or damaged parts must be replaced.
C. Fit O-rings (28, 29 and 30) in their recesses on the I/P
module (20). Refit I/P module (20) on manifold block
(144). Tighten screws (27).
Note: To ensure correct positioner performance, check
that all gaskets are perfectly leaktight.
Masoneilan VariPak Adjustable Cv Control Valves Instruction Manual
Spring ref.
Spring color
No.
code
114
Yellow
154
Red
114
White
154
Blue
114
White
154
Green
114
Yellow
154
Red
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