Samson 3351, Монтаж и эксплуатация

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6 EB 8039 EN
Design and principle of operation
4 Design and principle of oper-
ation
See Fig. 1.
Standard version for pressure rating PN 10
to 40 or Class 150 and 300, fail-close or
fail-open
Type 3351 · On/off valve with self-adjusting
PTFE V-ring packing in nominal size DN 15
to 100 (NPS ½ to 4) for medium tempera
-
tures from –10 to +220 °C (14 to 428 °F)
Type 3351 with bellows seal · On/off valve
with bellows seal and V-ring packing · Valve
size DN 15 to 50 (NPS ½ to 2) · Medium
temperatures from –50 to 250 °C (–58 to
482 °F)
Type 3351 with insulating section · On/off
valve with insulating section and plug stem
sealed by a PTFE V-ring packing · Valve size
DN 15 to 50 (NPS ½ to 2) · Medium tem -
peratures from –50 to +250 °C (–58 to
+482 °F)
Principle of operation
The connected pneumatic control pressure
(5.8) opposes the force of the spring (5.5) to
open or close the valve.
Depending on the design of the valve seat
(2) and where the plug (3) is located inside
the valve, the valve has two different fail-safe
actions which become effective when the
pressure is relieved from the diaphragm
(5.4) or the supply of control pressure fails.
− Fail-close valve: upon failure of the con-
trol pressure, the valve is closed by the
spring.
−
Fail-open valve: upon failure of the con-
trol pressure, the valve is opened by the
spring.
For versions with the optional handwheel (6),
a fail-close valve can be opened and a fail-
open valve can be closed in the event of con-
trol pressure failure.
1 Valve body
1.1 Nuts
1.2 Gasket
2
Seat
3 Plug
3.1 Plug stem
3.2 Lock nut
3.3 Washer
4
Packing
4.1 Spring
4.2 PTFE V-ring packing
4.3 Washer
5
Valve bonnet
5.1 Guide bushing
5.2 Threaded bushing
5.4 Diaphragm
5.5 Spring
5.6 Spring plate
5.7 Top diaphragm case
5.8 Connection for control
pressure
5.9 Nuts and bolts with
washers
6 Handwheel (optional)
7 Bonnet with actuator
(DN 100 only)
7.1 Diaphragm plate
7.2 Nut/lock nut
7.3 Nut
7.4 Flattened area