Samson 250 series, Монтаж и эксплуатация

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10 EB 8053 EN
Troubleshooting
5 Troubleshooting
External leakage can indicate that the pack -
ing is defective or the metal bellows is defec -
tive (in a version with a bellows seal).
If the valve does not close tightly, tight shut-
off may be impaired by dirt stuck between
the seat and plug or by damaged facings.
Î
In this case, remove parts, carefully clean
them and renew them, if necessary.
Î
Before starting any work on the valve
body, first remove the actuator (see sec
-
tion 5.1).
WARNING!
Risk of injury due to process medium
escaping under pressure.
Depressurize the relevant section of
the pipeline and, if necessary, drain
it as well. When used at high tem -
peratures, allow the plant section to
cool down to ambient temperature.
Tip:
Before performing maintenance
work, we recommend removing the
valve from the pipeline or the entire
valve construction when the valve is
welded into the pipeline.
5.1 Removing the actuator
from the valve
1. Mount the stem connector clamps (7) be -
tween the actuator stem and the plug
stem.
2. For fail-close actuators, apply a signal
pressure that is higher than the lower
bench range value (see nameplate) to the
actuator so that the ring nut (8.2) can be
unscrewed.
3. Unscrew the ring nut.
4. Disconnect the signal pressure again.
5. Remove the actuator from the valve yoke.
5.2 Replacing the packing in
standard valves
Note:
Contact your nearest SAMSON sub-
sidiary or the SAMSON After-sales
Service department for information
on suitable lubricants.
Î
See Fig. 1 on page 7
If the packing leaks, replace it as follows:
1. Unscrew the ring nut (5.4) and remove
the yoke (5.3) from the valve bonnet.
2. Unscrew the lock nut (6.2) and stem con -
nector nut (6.1). Unscrew the screw (5.5)
for the anti-rotation fixture. Remove the
anti-rotation fixture (5.6).
3. Undo screws (5) on the valve bonnet. Re -
move the valve bonnet along with the
plug stem (6).
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