IM-P006-07
CTLS Issue 12
19
0.7 mm
(0.028")
Straight edge
Straight edge
Fig. 8
12.
After locating the bellows seal assembly carefully over the plunger and tighten down to a torque of
115 N m.
13.
Check with straight edge again, that with the top of the bellows pressed lightly onto the top of the plunger,
there is a slight clearance - a mere line of light between the straight edge and the top of the bellows (see
Figure 8).
14.
Before reassembling the valve make sure that the gasket faces on both the pilot valve block and the
body are clean and that the main valve spring (
16
) is positioned correctly on top of the main valve head.
15.
Fit new gasket (
15
) and secure the pilot valve block assembly onto the body with the nuts (
11
). Tighten
these nuts to the torques shown in Table 1, page 20.
16.
Refit the 6 mm stainless steel pipework and retighten the union nuts to ensure a steam tight seal.
17.
Refit the two diaphragms (
9
) making sure that they are fitted the same way round as they were removed
and that all contact surfaces are clean. If necessary two new diaphragms can be fitted.
18.
Place the bottom spring plate (
7
) in position and secure the spring housing with the 4 x M10 nuts (
8
)
tightening to a torque of 50 N m.
19.
Replace the spring (
6
) and the top spring plate (
5
) turning the adjustment screw (
1
) until it just locates
on the top spring plate. Replace the cover (
12
) and the 'C' washer (
3
).
20.
Bring the valve back into commission by following as many steps as are necessary in Section 4.1,
'Start-up'.
Table 1
Recommended tightening torques for the pilot valve block securing nuts item (21)
Size of valve
Nut size
Tightening torque
DN15LC, DN15 and DN20
M10
40 N m
DN25 to DN50
M12
60 N m
Note: for DN40 and DN50 valves predating 1996:
M16
110 N m
DN80
M12
80 N m
Summary of Contents for DP143
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