IM-P117-39
CMGT Issue 1
12
6.4 Repacking the valve:
-
With the valve dismantled, insert the valve internals extractor tool through the upper and
lower sealing rings (
8
and
9
) and lantern bush (
7
) (See Figure 7).
-
Firmly tap to ensure that the tool bottoms out in the bore and with a quarter turn of
the handle carefully remove the two sealing rings (
8
and
9
) and the lantern bush (
7
).
-
Thoroughly clean the sealing rings housing and all the internals.
-
Fit new lower sealing ring (
9
), lantern bush (
7
) and upper sealing ring (
8
), ensuring they
fit perfectly. (
Note:
The lower and upper sealing rings are the same.)
-
Apply a thin layer of graphite based grease to threads only (not to internals and piston).
6.5 Reassembling the valve - See Figure 5:
-
Take the piston valve sub assembly (
6,7,8
and
9
), lightly inserting it into the pipeline
connector body (
1
) and applying an even downwards force using the bonnet
assembly (
2
) over the studs.
-
Fit the belleville washers (
5
) and nuts (
4
) and evenly tighten the bonnet assembly (
2
)
down to a torque of 12 Nm (8.9 lbf ft).
-
The valve handwheel can now be reinstalled as per the instructions in Section 6.1, paying
particular attention to the placement of the washers and torque figures.
-
At this point the backlash of the valve should be tested ensuring it is not more than
¼
of
a turn and that the securing nuts do not turn with the handwheel.
Table 1 Recommended tightening torques
Item
or
mm
N m
lbf ft
4
14
" x 18 UNC
12
8.9
11
10
M6
12
8.9
Summary of Contents for MSC-125
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