Samson 3351 - Page 16

3-2 EB 8039 EN
Design and principle of operation
DN100version
DN15to80version
with handwheel
Spring
opens
R=47mm
Spring
Closing
R=64mm
Detailed view:
connection for
control pressure
withG¼female
thread
Z
6
5.
7
5.4
5.6
5.5
3.2
3.1
5
5.2
4.2
4
4.3
4.1
5.1
5.9
3.3
3
2
1
5.8
A
B
Z
R
5.8
5.7
7.3
7.1
7.4
7.2
7
Fail-openFail-close
Fail-closeFail-open
1 Valve body
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
Fig.3-1: Functional diagram of Type3351 Pneumatic On/off Valve