Samson 3372 - Preloading the Springs; Tensioning the Springs

6-2 EB 8313-3 EN
Start-up
Î Before unblocking the actuator stem after
it has become blocked (e.g. due to seiz-
ing up after remaining in the same posi-
tion for a long time), release any stored
energy in the actuator (e.g. spring com-
pression). See 'Relieving the spring com-
pression in the actuator' in the 'Removal'
section.
Risk of actuator damage due to excessively
high or low tightening torques.
Observe the specied torques on tightening
actuator components. Excessively tightened
torques lead to parts wearing out quicker.
Parts that are not tightened far enough may
loosen.
Î Observe the specied tightening torques
(uAB0100).
Risk of actuator damage due to the use of
unsuitable tools.
Î Only use tools approved by SAMSON
(uAB0100).
6.1 Preloading the springs
See Fig.6-1
By preloading the springs in the actuator, the
following can be achieved:
− The thrust is increased (only actuators
with "stem extends")
− In combination with a SAMSON valve:
the actuator travel range can be adapted
to a smaller valve travel range
6.1.1 Tensioning the springs
Risk of actuator damage due to the springs
being tensioned unevenly.
Î Distribute clamping bolts and nuts evenly
around the circumference.
Î Tighten the nuts gradually in a crisscross
pattern.
Only the springs in actuators with 350cm²
area can be preloaded.
1. Distribute the long bolts (A22) evenly
around the circumference.
2. Screw the nuts (A21) with shims (A25)
onto the clamping bolts (A22) until they
rest on the bottom diaphragm case (A2).
3. To tension the springs evenly, tighten the
nuts (A21) gradually in a crisscross pat-
tern until both diaphragm cases (A1, A2)
rest on the diaphragm (A4). Hold the
bolt head stationary with a suitable tool
and apply the tightening torque to the
nuts. Observe tightening torques.
4. Insert the short bolts (A20) through the
intended holes in the diaphragm cases
(A1, A2).
NOTICE
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NOTICE
!
NOTICE
!
Note