Samson EB 8061 EN, Перевод оригинальной инструкции

Страница: 17 / 92

EB 8061 EN 3-3
Design and principle of operation
3.2 Versions
With insulating section/bellows seal
The modular design allows an insulating sec-
tion or bellows seal to be fitted to the stan-
dard valve version.
Actuators
In these instructions, the preferable combina-
tion with a SAMSON Type 3271 or
Type 3277 Pneumatic Actuator is described.
The pneumatic actuator (with or without
handwheel) can be replaced by another
pneumatic actuator in a different size, but
with the same travel.
Î
Observe the maximum permissible actu-
ator force.
If the travel range of the actuator is larger
than the travel range of the valve, the spring
assembly in the actuator must be preloaded
so that the travel ranges match. See associ -
ated actuator documentation.
The basic pneumatic actuator can be re -
placed by a pneumatic actuator with addi-
tional handwheel or by an electric actuator
(see Information Sheet
u
T 8300).
3.3 Additional fittings
Strainers
We recommend installing a SAMSON
strainer upstream of the valve. It prevents
solid particles in the process medium from
damaging the valve.
Bypass and shut-off valves
We recommend installing a shut-off valve
both upstream of the strainer and down -
stream of the valve and installing a bypass
line. The bypass ensures that the plant does
not need to be shut down for service and re-
pair work on the valve.
Insulation
Control valves can be insulated to reduce
heat energy transfer.
Refer to the instructions in the 'Installation'
section.
Test connection
Versions with bellows seal fitted with a test
connection (G
1 /
8
) at the top flange allow the
sealing ability of the bellows to be moni-
tored.
Particularly for liquids and vapors, we rec-
ommend installing a suitable leakage indica-
tor (e.g. a contact pressure gauge, an outlet
to an open vessel or an inspection glass).
Safety guard
For operating conditions that require in-
creased safety (e.g. in cases where the valve
is freely accessible to untrained staff), a safe-
ty guard must be installed to rule out a crush
hazard arising from moving parts (actuator
and plug stem). Plant operators are responsi-
ble for deciding whether a guard is to be
used. The decision is based on the risk posed
by the plant and its operating conditions.
Noise emissions
Trims with flow dividers can be used to re-
duce noise emission (
u
T 8081).
Note