Samson 3351 - Versions; Additional Fittings; Accessories

EB 8039 EN 3-3
Design and principle of operation
3.1 V
ersions
Standard versionforpressureratingPN16
to40orClass125and300,fail-closeor
fail-open
Type3351 · On/off valve with self-adjusting
PTFEV-ringpackinginvalvesizeDN15to
100(NPS½to4)formediumtemperatures
from–10to+220°C(14to428°F)
Further versions:
− Additionalmanualoverride·DN15to
80(NPS½to3)
− Higher ambient temperatures
− Version without PTFE for the tobacco in-
dustry
− Adjustable packings
− Packings with special materials
3.2 Additionalttings
Strainers
We recommend installing a SAMSON
strainer upstream of the valve. It prevents sol-
id 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.
Test connection
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) at
the test connection.
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.
3.3 Accessories
SAMSON provides mounting kits with addi-
tional parts to mount valve accessories (e.g.
Type3768LimitSwitch,Type3730Position-
er). Specify the item number listed in Table
3-6 to order the suitable mounting kit from
SAMSON.