Samson 3241-1, Монтаж и эксплуатация

Страница: 10 / 24

5 Maintenance – Replacing parts
The control valve is subject to natural wear,
especially at the seat, plug and packing.
Depending on the application, the valve
needs to be checked regularly to prevent
against possible failures.
If leakage occurs, this could be caused by a
damaged packing or a defective metal bel-
lows.
If the valve does not seal properly, the tight
shut-off may be impeded by dirt or other im-
purities caught between the seat and plug,
or by damaged seating surfaces.
Remove the parts, clean them thoroughly
and replace them with new ones, if neces-
sary.
Note!
When mounting the bonnet, the large
V-shaped port of the V-port plug must face
towards the valve outlet.
Caution!
Before servicing or disassembling the
control valve, depressurize the con-
cerned section of the plant and drain
it, if necessary, depending on the
medium used. Switch off the signal
pressure for the actuator and remove
the signal pressure line. As valves
are not free of cavities, there might
still be residual medium in the valve.
This applies, in particular, for valve
versions with extension bonnet and
metal bellows seal.
Caution!
On performing any work on the valve, first
shut off the signal pressure, disconnect the
signal pressure line and remove the actua-
tor.
Note!
Suitable seat and special tools as well as the
appropriate tightening torques required for
installation are listed in EB 029 EN (formerly
WA 029 EN). The instructions can be
viewed on the Internet at
www.samson.de/pdf_en/e00290en.pdf.
Removing the actuator:
1. Before disassembling an actuator with
fail-safe action "Actuator stem extends"
and particularly an actuator with
preloaded springs, apply a pressure to
the lower signal pressure connection that
slightly exceeds the lower bench range
value (see nameplate), so that you can
remove the ring nut (8.2). Remove the
stem connector clamps (7) and the ring
nut (8.2).
2. Remove the actuator from the valve bon-
net.
10
EB 8015 EN
Maintenance – Replacing parts