Samson 3241-1-Gas, Mounting And Operating Instructions

Page: 19 / 56

EB 8020-1 EN 19
Design and principle of operation
3.1 Fail-safe positions
The fail‑safe position depends on the mount‑
ed actuator.
Depending on how the compression springs
are arranged in the pneumatic actuator, the
valve has two different fail‑safe positions:
Actuator stem extends (FA)
When the signal pressure is reduced or the
air supply fails, the springs move the
actuator stem downward and close the
valve. The valve opens when the signal
pressure is increased enough to overcome
the force exerted by the springs.
Actuator stem retracts (FE)
When the signal pressure is reduced or the
air supply fails, the springs move the
actuator stem upwards and open the valve.
The valve closes when the signal pressure is
increased enough to overcome the force
exerted by the springs.
The "stem retracts" direction of action is only
permitted for a certain version designated
for valve class E. See Table 9.
3.2 Versions
Actuators
Î
To select a suitable actuator, see Table 6
(valve class D) or Table 9 (valve class E).
3.3 Technical data
The nameplate provides information on the
control valve version (see section 2.1).
3.3.1 Common technical data
− DIN DVGW test mark
The valves were typetested by TÜV (Ger‑
man technical surveillance association)
and received the test mark by DVGW
(German Technical and Scientific Associ‑
ation for Gas and Water) as specified in
Table 5 or Table 8.
− Compliance
The Type 3241G Valve bears both the
CE and EAC marks of conformity.
− Leakage class
Leakage class according to DIN EN 161
Note