Versions; Additional Fittings; Accessories - Samson 3351 Mounting And Operating Instructions

3.1 Versions

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 fittings
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-
EB 8039 EN
Design and principle of operation
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.
3-3